diff --git a/libcxx/docs/Status/RangesAlgorithms.csv b/libcxx/docs/Status/RangesAlgorithms.csv
--- a/libcxx/docs/Status/RangesAlgorithms.csv
+++ b/libcxx/docs/Status/RangesAlgorithms.csv
@@ -11,10 +11,10 @@
 Search,equal,Not assigned,n/a,Not started
 Search,lexicographical_compare,Not assigned,n/a,Not started
 Search,partition_point,Christopher Di Bella,`D105794 <https://llvm.org/D105794>`_,Under review
-Search,lower_bound,Christopher Di Bella,`D105795 <https://llvm.org/D105795>`_,Under review
-Search,upper_bound,Christopher Di Bella,`D105795 <https://llvm.org/D105795>`_,Under review
+Search,lower_bound,Nikolas Klauser,`D121964 <https://llvm.org/D121964>`_,✅
+Search,upper_bound,Nikolas Klauser,`D121964 <https://llvm.org/D121964>`_,✅
 Search,equal_range,Christopher Di Bella,n/a,Not started
-Search,binary_search,Christopher Di Bella,n/a,Not started
+Search,binary_search,Nikolas Klauser,`D121964 <https://llvm.org/D121964>`_,✅
 Search,min,Nikolas Klauser,`D119589 <https://llvm.org/D119589>`_,✅
 Search,max,Nikolas Klauser,`D122002 <https://llvm.org/D122002>`_,✅
 Search,minmax,Nikolas Klauser,`D120637 <https://llvm.org/D120637>`_,✅
diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -66,6 +66,7 @@
   __algorithm/pop_heap.h
   __algorithm/prev_permutation.h
   __algorithm/push_heap.h
+  __algorithm/ranges_binary_search.h
   __algorithm/ranges_copy.h
   __algorithm/ranges_copy_backward.h
   __algorithm/ranges_copy_if.h
@@ -75,6 +76,7 @@
   __algorithm/ranges_find.h
   __algorithm/ranges_find_if.h
   __algorithm/ranges_find_if_not.h
+  __algorithm/ranges_lower_bound.h
   __algorithm/ranges_max.h
   __algorithm/ranges_max_element.h
   __algorithm/ranges_min.h
@@ -84,6 +86,7 @@
   __algorithm/ranges_mismatch.h
   __algorithm/ranges_swap_ranges.h
   __algorithm/ranges_transform.h
+  __algorithm/ranges_upper_bound.h
   __algorithm/remove.h
   __algorithm/remove_copy.h
   __algorithm/remove_copy_if.h
diff --git a/libcxx/include/__algorithm/ranges_binary_search.h b/libcxx/include/__algorithm/ranges_binary_search.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_binary_search.h
@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H
+#define _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H
+
+#include <__algorithm/ranges_lower_bound.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __binary_search {
+struct __fn {
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<_Iter, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter __first, _Sent __last, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __ret = ranges::__lower_bound_impl(__first, __last, __value, __comp, __proj);
+    return __ret != __last && !std::invoke(__comp, __value, std::invoke(__proj, *__first));
+  }
+
+  template <forward_range _Range, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range&& __r, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __first = ranges::begin(__r);
+    auto __last = ranges::end(__r);
+    auto __ret = ranges::__lower_bound_impl(__first, __last, __value, __comp, __proj);
+    return __ret != __last && !std::invoke(__comp, __value, std::invoke(__proj, *__first));
+  }
+};
+} // namespace __binary_search
+
+inline namespace __cpo {
+  inline constexpr auto binary_search = __binary_search::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H
diff --git a/libcxx/include/__algorithm/ranges_lower_bound.h b/libcxx/include/__algorithm/ranges_lower_bound.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_lower_bound.h
@@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___ALGORITHM_RANGES_LOWER_BOUND_H
+#define _LIBCPP___ALGORITHM_RANGES_LOWER_BOUND_H
+
+#include <__algorithm/half_positive.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/advance.h>
+#include <__iterator/concepts.h>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Iter, class _Sent, class _Type, class _Proj, class _Comp>
+_LIBCPP_HIDE_FROM_ABI constexpr
+_Iter __lower_bound_impl(_Iter __first, _Sent __last, const _Type& __value, _Comp& __comp, _Proj& __proj) {
+  using __diff_t = typename iterator_traits<_Iter>::difference_type;
+  __diff_t __len = std::distance(__first, __last);
+
+  while (__len != 0) {
+    __diff_t __len2 = std::__half_positive(__len);
+    _Iter __m = __first;
+    std::advance(__m, __len2);
+    if (std::invoke(__comp, std::invoke(__proj, *__m), __value)) {
+      __first = ++__m;
+      __len -= __len2 + 1;
+    } else {
+      __len = __len2;
+    }
+  }
+
+  return __first;
+}
+
+namespace __lower_bound {
+struct __fn {
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<_Iter, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
+    return ranges::__lower_bound_impl(__first, __last, __value, __comp, __proj);
+  }
+
+  template <forward_range _Range, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __r,
+                                         const _Type& __value,
+                                         _Comp __comp = {},
+                                         _Proj __proj = {}) const {
+    return ranges::__lower_bound_impl(ranges::begin(__r), ranges::end(__r), __value, __comp, __proj);
+  }
+};
+} // namespace __lower_bound
+
+inline namespace __cpo {
+  inline constexpr auto lower_bound = __lower_bound::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_LOWER_BOUND_H
diff --git a/libcxx/include/__algorithm/ranges_upper_bound.h b/libcxx/include/__algorithm/ranges_upper_bound.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_upper_bound.h
@@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___ALGORITHM_RANGES_UPPER_BOUND_H
+#define _LIBCPP___ALGORITHM_RANGES_UPPER_BOUND_H
+
+#include <__algorithm/ranges_lower_bound.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __upper_bound {
+struct __fn {
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<_Iter, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return !std::invoke(__comp, __rhs, __lhs); };
+    return __lower_bound_impl(__first, __last, __value, __comp_lhs_rhs_swapped, __proj);
+  }
+
+  template <forward_range _Range, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __r,
+                                         const _Type& __value,
+                                         _Comp __comp = {},
+                                         _Proj __proj = {}) const {
+    auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return !std::invoke(__comp, __rhs, __lhs); };
+    return __lower_bound_impl(ranges::begin(__r), ranges::end(__r), __value, __comp_lhs_rhs_swapped, __proj);
+  }
+};
+} // namespace __upper_bound
+
+inline namespace __cpo {
+  inline constexpr auto upper_bound = __upper_bound::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_UPPER_BOUND_H
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -238,6 +238,37 @@
     requires indirectly_copyable<iterator_t<R>, I>
     constexpr ranges::copy_backward_result<borrowed_iterator_t<R>, I>
       ranges::copy_backward(R&& r, I result);                                               // since C++20
+
+  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
+           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
+    constexpr I upper_bound(I first, S last, const T& value, Comp comp = {}, Proj proj = {}); // since C++20
+
+  template<forward_range R, class T, class Proj = identity,
+           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
+             ranges::less>
+    constexpr borrowed_iterator_t<R>
+      upper_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});                     // since C++20
+
+  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
+           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
+    constexpr I lower_bound(I first, S last, const T& value, Comp comp = {},
+                                    Proj proj = {});                                          // since C++20
+  template<forward_range R, class T, class Proj = identity,
+           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
+             ranges::less>
+    constexpr borrowed_iterator_t<R>
+      lower_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});                     // since C++20
+
+  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
+           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
+    constexpr bool binary_search(I first, S last, const T& value, Comp comp = {},
+                                         Proj proj = {});                                     // since C++20
+  template<forward_range R, class T, class Proj = identity,
+           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
+             ranges::less>
+    constexpr bool binary_search(R&& r, const T& value, Comp comp = {},
+                                         Proj proj = {});                                     // since C++20
+
 }
 
     constexpr bool     // constexpr in C++20
@@ -955,6 +986,7 @@
 #include <__algorithm/pop_heap.h>
 #include <__algorithm/prev_permutation.h>
 #include <__algorithm/push_heap.h>
+#include <__algorithm/ranges_binary_search.h>
 #include <__algorithm/ranges_copy.h>
 #include <__algorithm/ranges_copy_backward.h>
 #include <__algorithm/ranges_copy_if.h>
@@ -964,6 +996,7 @@
 #include <__algorithm/ranges_find.h>
 #include <__algorithm/ranges_find_if.h>
 #include <__algorithm/ranges_find_if_not.h>
+#include <__algorithm/ranges_lower_bound.h>
 #include <__algorithm/ranges_max.h>
 #include <__algorithm/ranges_max_element.h>
 #include <__algorithm/ranges_min.h>
@@ -973,6 +1006,7 @@
 #include <__algorithm/ranges_mismatch.h>
 #include <__algorithm/ranges_swap_ranges.h>
 #include <__algorithm/ranges_transform.h>
+#include <__algorithm/ranges_upper_bound.h>
 #include <__algorithm/remove.h>
 #include <__algorithm/remove_copy.h>
 #include <__algorithm/remove_copy_if.h>
diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
--- a/libcxx/include/module.modulemap
+++ b/libcxx/include/module.modulemap
@@ -294,6 +294,7 @@
       module pop_heap                 { private header "__algorithm/pop_heap.h" }
       module prev_permutation         { private header "__algorithm/prev_permutation.h" }
       module push_heap                { private header "__algorithm/push_heap.h" }
+      module ranges_binary_search     { private header "__algorithm/ranges_binary_search.h" }
       module ranges_copy              { private header "__algorithm/ranges_copy.h" }
       module ranges_copy_backward     { private header "__algorithm/ranges_copy_backward.h" }
       module ranges_copy_if           { private header "__algorithm/ranges_copy_if.h" }
@@ -303,6 +304,7 @@
       module ranges_find              { private header "__algorithm/ranges_find.h" }
       module ranges_find_if           { private header "__algorithm/ranges_find_if.h" }
       module ranges_find_if_not       { private header "__algorithm/ranges_find_if_not.h" }
+      module ranges_lower_bound       { private header "__algorithm/ranges_lower_bound.h" }
       module ranges_max               { private header "__algorithm/ranges_max.h" }
       module ranges_max_element       { private header "__algorithm/ranges_max_element.h" }
       module ranges_min               { private header "__algorithm/ranges_min.h" }
@@ -312,6 +314,7 @@
       module ranges_mismatch          { private header "__algorithm/ranges_mismatch.h" }
       module ranges_swap_ranges       { private header "__algorithm/ranges_swap_ranges.h" }
       module ranges_transform         { private header "__algorithm/ranges_transform.h" }
+      module ranges_upper_bound       { private header "__algorithm/ranges_upper_bound.h" }
       module remove                   { private header "__algorithm/remove.h" }
       module remove_copy              { private header "__algorithm/remove_copy.h" }
       module remove_copy_if           { private header "__algorithm/remove_copy_if.h" }
diff --git a/libcxx/test/libcxx/algorithms/ranges_robust_against_copying_comparators.pass.cpp b/libcxx/test/libcxx/algorithms/ranges_robust_against_copying_comparators.pass.cpp
--- a/libcxx/test/libcxx/algorithms/ranges_robust_against_copying_comparators.pass.cpp
+++ b/libcxx/test/libcxx/algorithms/ranges_robust_against_copying_comparators.pass.cpp
@@ -96,8 +96,8 @@
     //(void)std::ranges::all_of(a, UnaryTrue(&copies)); assert(copies == 0);
     //(void)std::ranges::any_of(first, last, UnaryTrue(&copies)); assert(copies == 0);
     //(void)std::ranges::any_of(a, UnaryTrue(&copies)); assert(copies == 0);
-    //(void)std::ranges::binary_search(first, last, value, Less(&copies)); assert(copies == 0);
-    //(void)std::ranges::binary_search(a, value, Less(&copies)); assert(copies == 0);
+    (void)std::ranges::binary_search(first, last, value, Less(&copies)); assert(copies == 0);
+    (void)std::ranges::binary_search(a, value, Less(&copies)); assert(copies == 0);
     //(void)std::ranges::clamp(value, value, value, Less(&copies)); assert(copies == 0);
     (void)std::ranges::count_if(first, last, UnaryTrue(&copies)); assert(copies == 0);
     (void)std::ranges::count_if(a, UnaryTrue(&copies)); assert(copies == 0);
@@ -142,8 +142,8 @@
     //if (!std::is_constant_evaluated()) { (void)std::ranges::inplace_merge(a, mid, Less(&copies)); assert(copies == 0); }
     //(void)std::ranges::lexicographical_compare(first, last, first2, last2, Less(&copies)); assert(copies == 0);
     //(void)std::ranges::lexicographical_compare(a, b, Less(&copies)); assert(copies == 0);
-    //(void)std::ranges::lower_bound(first, last, value, Less(&copies)); assert(copies == 0);
-    //(void)std::ranges::lower_bound(a, value, Less(&copies)); assert(copies == 0);
+    (void)std::ranges::lower_bound(first, last, value, Less(&copies)); assert(copies == 0);
+    (void)std::ranges::lower_bound(a, value, Less(&copies)); assert(copies == 0);
     //(void)std::ranges::make_heap(first, last, Less(&copies)); assert(copies == 0);
     //(void)std::ranges::make_heap(a, Less(&copies)); assert(copies == 0);
     //(void)std::ranges::max(value, value, Less(&copies)); assert(copies == 0);
@@ -226,8 +226,8 @@
     //(void)std::ranges::unique(a, Equal(&copies)); assert(copies == 0);
     //(void)std::ranges::unique_copy(first, last, first2, Equal(&copies)); assert(copies == 0);
     //(void)std::ranges::unique_copy(a, first2, Equal(&copies)); assert(copies == 0);
-    //(void)std::ranges::upper_bound(first, last, value, Less(&copies)); assert(copies == 0);
-    //(void)std::ranges::upper_bound(a, value, Less(&copies)); assert(copies == 0);
+    (void)std::ranges::upper_bound(first, last, value, Less(&copies)); assert(copies == 0);
+    (void)std::ranges::upper_bound(a, value, Less(&copies)); assert(copies == 0);
 
     return true;
 }
diff --git a/libcxx/test/libcxx/private_headers.verify.cpp b/libcxx/test/libcxx/private_headers.verify.cpp
--- a/libcxx/test/libcxx/private_headers.verify.cpp
+++ b/libcxx/test/libcxx/private_headers.verify.cpp
@@ -103,6 +103,7 @@
 #include <__algorithm/pop_heap.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/pop_heap.h'}}
 #include <__algorithm/prev_permutation.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/prev_permutation.h'}}
 #include <__algorithm/push_heap.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/push_heap.h'}}
+#include <__algorithm/ranges_binary_search.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_binary_search.h'}}
 #include <__algorithm/ranges_copy.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_copy.h'}}
 #include <__algorithm/ranges_copy_backward.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_copy_backward.h'}}
 #include <__algorithm/ranges_copy_if.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_copy_if.h'}}
@@ -112,6 +113,7 @@
 #include <__algorithm/ranges_find.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_find.h'}}
 #include <__algorithm/ranges_find_if.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_find_if.h'}}
 #include <__algorithm/ranges_find_if_not.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_find_if_not.h'}}
+#include <__algorithm/ranges_lower_bound.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_lower_bound.h'}}
 #include <__algorithm/ranges_max.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_max.h'}}
 #include <__algorithm/ranges_max_element.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_max_element.h'}}
 #include <__algorithm/ranges_min.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_min.h'}}
@@ -121,6 +123,7 @@
 #include <__algorithm/ranges_mismatch.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_mismatch.h'}}
 #include <__algorithm/ranges_swap_ranges.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_swap_ranges.h'}}
 #include <__algorithm/ranges_transform.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_transform.h'}}
+#include <__algorithm/ranges_upper_bound.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/ranges_upper_bound.h'}}
 #include <__algorithm/remove.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/remove.h'}}
 #include <__algorithm/remove_copy.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/remove_copy.h'}}
 #include <__algorithm/remove_copy_if.h> // expected-error@*:* {{use of private header from outside its module: '__algorithm/remove_copy_if.h'}}
diff --git a/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/binary.search/ranges.binary_search.pass.cpp b/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/binary.search/ranges.binary_search.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/binary.search/ranges.binary_search.pass.cpp
@@ -0,0 +1,173 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-has-no-incomplete-ranges
+
+// template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
+//          indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
+//   constexpr bool ranges::binary_search(I first, S last, const T& value, Comp comp = {},
+//                                        Proj proj = {});
+// template<forward_range R, class T, class Proj = identity,
+//          indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
+//            ranges::less>
+//   constexpr bool ranges::binary_search(R&& r, const T& value, Comp comp = {},
+//                                        Proj proj = {});
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <ranges>
+
+#include "almost_satisfies_types.h"
+#include "test_iterators.h"
+
+struct NotLessThanComparable {};
+
+template <class It, class Sent = It>
+concept HasLowerBoundIt = requires(It it, Sent sent) { std::ranges::binary_search(it, sent, 1); };
+
+static_assert(HasLowerBoundIt<int*>);
+static_assert(!HasLowerBoundIt<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>);
+static_assert(!HasLowerBoundIt<ForwardIteratorNotDerivedFrom>);
+static_assert(!HasLowerBoundIt<ForwardIteratorNotIncrementable>);
+static_assert(!HasLowerBoundIt<NotLessThanComparable*>);
+
+template <class Range>
+concept HasLowerBoundR = requires(Range range) { std::ranges::binary_search(range, 1); };
+
+static_assert(HasLowerBoundR<std::array<int, 1>>);
+static_assert(!HasLowerBoundR<ForwardRangeNotDerivedFrom>);
+static_assert(!HasLowerBoundR<ForwardRangeNotIncrementable>);
+static_assert(!HasLowerBoundR<UncheckedRange<NotLessThanComparable*>>);
+
+template <class Pred>
+concept HasLowerBoundPred = requires(int* it, Pred pred) {std::ranges::binary_search(it, it, 1, pred); };
+
+static_assert(HasLowerBoundPred<std::ranges::less>);
+static_assert(!HasLowerBoundPred<IndirectUnaryPredicateNotCopyConstructible>);
+static_assert(!HasLowerBoundPred<IndirectUnaryPredicateNotPredicate>);
+
+template <class It>
+constexpr void test_iterators() {
+  { // simple test
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      std::same_as<bool> auto ret = std::ranges::binary_search(It(a), It(a + 6), 3);
+      assert(base(ret));
+    }
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      std::same_as<bool> auto ret = std::ranges::binary_search(range, 3);
+      assert(base(ret));
+    }
+  }
+
+  { // check that the predicate is used
+    int a[] = {6, 5, 4, 3, 2, 1};
+    assert(std::ranges::binary_search(It(a), It(a + 6), 2, std::ranges::greater{}));
+    auto range = std::ranges::subrange(It(a), It(a + 6));
+    assert(std::ranges::binary_search(range, 2, std::ranges::greater{}));
+  }
+
+  { // check that the projection is used
+    int a[] = {1, 2, 3, 4, 5, 6};
+    assert(std::ranges::binary_search(It(a), It(a + 6), 0, {}, [](int i) { return i - 3; }));
+    auto range = std::ranges::subrange(It(a), It(a + 6));
+    assert(std::ranges::binary_search(range, 0, {}, [](int i) { return i - 3; }));
+  }
+
+  { // check that true is returned with multiple matches
+    int a[] = {1, 2, 2, 2, 3};
+    assert(std::ranges::binary_search(It(a), It(a + 5), 2));
+    auto range = std::ranges::subrange(It(a), It(a + 5));
+    assert(std::ranges::binary_search(range, 2));
+  }
+
+  { // check that false is returned if all elements compare less than
+    int a[] = {1, 2, 3, 4};
+    assert(!std::ranges::binary_search(It(a), It(a + 4), 5));
+    auto range = std::ranges::subrange(It(a), It(a + 4));
+    assert(!std::ranges::binary_search(a, 5));
+  }
+
+  { // check that false is returned if no element compares less than
+    int a[] = {1, 2, 3, 4};
+    assert(!std::ranges::binary_search(It(a), It(a + 4), 0));
+    auto range = std::ranges::subrange(It(a), It(a + 4));
+    assert(!std::ranges::binary_search(range, 0));
+  }
+
+  { // check that a single element works
+    int a[] = {1};
+    assert(std::ranges::binary_search(It(a), It(a + 1), 1));
+    auto range = std::ranges::subrange(It(a), It(a + 1));
+    assert(std::ranges::binary_search(range, 1));
+  }
+
+  { // check that an even number of elements works and that searching for the first element works
+    int a[] = {1, 2, 7, 8, 10, 11};
+    assert(std::ranges::binary_search(It(a), It(a + 6), 1));
+    auto range = std::ranges::subrange(It(a), It(a + 6));
+    assert(std::ranges::binary_search(range, 1));
+  }
+
+  { // check that an odd number of elements works and that searching for the last element works
+    int a[] = {1, 2, 7, 10, 11};
+    assert(std::ranges::binary_search(It(a), It(a + 5), 11));
+    auto range = std::ranges::subrange(It(a), It(a + 5));
+    assert(std::ranges::binary_search(range, 11));
+  }
+
+  { // check that it works when all but the searched for elements are equal
+    int a[] = {1, 2, 2, 2, 2};
+    assert(std::ranges::binary_search(It(a), It(a + 5), 1));
+    auto range = std::ranges::subrange(It(a), It(a + 5));
+    assert(std::ranges::binary_search(range, 1));
+  }
+}
+
+constexpr bool test() {
+  test_iterators<int*>();
+  test_iterators<forward_iterator<int*>>();
+  test_iterators<bidirectional_iterator<int*>>();
+  test_iterators<random_access_iterator<int*>>();
+  test_iterators<contiguous_iterator<int*>>();
+
+  { // check that std::invoke is used
+    struct S { int check; int other; };
+    S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+    assert(std::ranges::binary_search(a, a + 6, 4, {}, &S::check));
+    assert(std::ranges::binary_search(a, 4, {}, &S::check));
+  }
+
+  { // check that an empty range works
+    std::array<int, 0> a;
+    assert(!std::ranges::binary_search(a.begin(), a.end(), 1));
+    assert(!std::ranges::binary_search(a, 1));
+  }
+
+  { // check that a non-const operator() works
+    struct Func {
+      constexpr bool operator()(const int& i, const int& j) { return i < j; }
+    };
+    int a[] = {1, 6, 9, 10, 23};
+    assert(std::ranges::binary_search(a, 6, Func{}));
+    assert(std::ranges::binary_search(a, a + 5, 6, Func{}));
+  }
+
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}
diff --git a/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/lower.bound/ranges.lower_bound.pass.cpp b/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/lower.bound/ranges.lower_bound.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/lower.bound/ranges.lower_bound.pass.cpp
@@ -0,0 +1,273 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-has-no-incomplete-ranges
+
+// template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
+//          indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
+//   constexpr I ranges::lower_bound(I first, S last, const T& value, Comp comp = {},
+//                                   Proj proj = {});
+// template<forward_range R, class T, class Proj = identity,
+//          indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
+//            ranges::less>
+//   constexpr borrowed_iterator_t<R>
+//     ranges::lower_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <ranges>
+
+#include "almost_satisfies_types.h"
+#include "test_iterators.h"
+
+struct NotLessThanComparable {};
+
+template <class It, class Sent = It>
+concept HasLowerBoundIt = requires(It it, Sent sent) { std::ranges::lower_bound(it, sent, 1); };
+
+static_assert(HasLowerBoundIt<int*>);
+static_assert(!HasLowerBoundIt<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>);
+static_assert(!HasLowerBoundIt<ForwardIteratorNotDerivedFrom>);
+static_assert(!HasLowerBoundIt<ForwardIteratorNotIncrementable>);
+static_assert(!HasLowerBoundIt<NotLessThanComparable*>);
+
+template <class Range>
+concept HasLowerBoundR = requires(Range range) { std::ranges::lower_bound(range, 1); };
+
+static_assert(HasLowerBoundR<std::array<int, 1>>);
+static_assert(!HasLowerBoundR<ForwardRangeNotDerivedFrom>);
+static_assert(!HasLowerBoundR<ForwardRangeNotIncrementable>);
+static_assert(!HasLowerBoundR<UncheckedRange<NotLessThanComparable*>>);
+
+template <class Pred>
+concept HasLowerBoundPred = requires(int* it, Pred pred) {std::ranges::lower_bound(it, it, 1, pred); };
+
+static_assert(HasLowerBoundPred<std::ranges::less>);
+static_assert(!HasLowerBoundPred<IndirectUnaryPredicateNotCopyConstructible>);
+static_assert(!HasLowerBoundPred<IndirectUnaryPredicateNotPredicate>);
+
+template <class It>
+constexpr void test_iterators() {
+  { // simple test
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      std::same_as<It> auto ret = std::ranges::lower_bound(It(a), It(a + 6), 3);
+      assert(base(ret) == a + 2);
+    }
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      std::same_as<It> auto ret = std::ranges::lower_bound(range, 3);
+      assert(base(ret) == a + 2);
+    }
+  }
+
+  { // check that the predicate is used
+    {
+      int a[] = {6, 5, 4, 3, 2, 1};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 6), 2, std::ranges::greater{});
+      assert(base(ret) == a + 4);
+    }
+    {
+      int a[] = {6, 5, 4, 3, 2, 1};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      auto ret = std::ranges::lower_bound(range, 2, std::ranges::greater{});
+      assert(base(ret) == a + 4);
+    }
+  }
+
+  { // check that the projection is used
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 6), 0, {}, [](int i) { return i - 3; });
+      assert(base(ret) == a + 2);
+    }
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      auto ret = std::ranges::lower_bound(range, 0, {}, [](int i) { return i - 3; });
+      assert(base(ret) == a + 2);
+    }
+  }
+
+  { // check that the last lower bound is returned
+    {
+      int a[] = {1, 2, 2, 2, 3};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 5), 2);
+      assert(base(ret) == a + 1);
+    }
+    {
+      int a[] = {1, 2, 2, 2, 3};
+      auto range = std::ranges::subrange(It(a), It(a + 5));
+      auto ret = std::ranges::lower_bound(range, 2);
+      assert(base(ret) == a + 1);
+    }
+  }
+
+  { // check that end is returned if all elements compare less than
+    {
+      int a[] = {1, 2, 3, 4};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 4), 5);
+      assert(base(ret) == a + 4);
+    }
+    {
+      int a[] = {1, 2, 3, 4};
+      auto range = std::ranges::subrange(It(a), It(a + 4));
+      auto ret = std::ranges::lower_bound(range, 5);
+      assert(base(ret) == a + 4);
+    }
+  }
+
+  { // check that the first element is returned if no element compares less than
+    {
+      int a[] = {1, 2, 3, 4};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 4), 0);
+      assert(base(ret) == a);
+    }
+    {
+      int a[] = {1, 2, 3, 4};
+      auto range = std::ranges::subrange(It(a), It(a + 4));
+      auto ret = std::ranges::lower_bound(range, 0);
+      assert(base(ret) == a);
+    }
+  }
+
+  { // check that a single element works
+    {
+      int a[] = {1};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 1), 1);
+      assert(base(ret) == a);
+    }
+    {
+      int a[] = {1};
+      auto range = std::ranges::subrange(It(a), It(a + 1));
+      auto ret = std::ranges::lower_bound(range, 1);
+      assert(base(ret) == a);
+    }
+  }
+
+  { // check that an even number of elements works
+    {
+      int a[] = {1, 3, 6, 6, 7, 8};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 6), 6);
+      assert(base(ret) == a + 2);
+    }
+    {
+      int a[] = {1, 3, 6, 6, 7, 8};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      auto ret = std::ranges::lower_bound(range, 6);
+      assert(base(ret) == a + 2);
+    }
+  }
+
+  { // check that an odd number of elements works
+    {
+      int a[] = {1, 3, 6, 6, 7};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 5), 6);
+      assert(base(ret) == a + 2);
+    }
+    {
+      int a[] = {1, 3, 6, 6, 7};
+      auto range = std::ranges::subrange(It(a), It(a + 5));
+      auto ret = std::ranges::lower_bound(range, 6);
+      assert(base(ret) == a + 2);
+    }
+  }
+
+  { // check that it works when all but the searched for element are equal
+    {
+      int a[] = {1, 6, 6, 6, 6, 6};
+      auto ret = std::ranges::lower_bound(It(a), It(a + 6), 1);
+      assert(base(ret) == a);
+    }
+    {
+      int a[] = {1, 6, 6, 6, 6, 6};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      auto ret = std::ranges::lower_bound(range, 1);
+      assert(base(ret) == a);
+    }
+  }
+}
+
+constexpr bool test() {
+  test_iterators<int*>();
+  test_iterators<forward_iterator<int*>>();
+  test_iterators<bidirectional_iterator<int*>>();
+  test_iterators<random_access_iterator<int*>>();
+  test_iterators<contiguous_iterator<int*>>();
+
+  { // check that std::invoke is used for the projections
+    {
+      struct S { int check; int other; };
+      S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+      auto ret = std::ranges::lower_bound(a, a + 6, 4, {}, &S::check);
+      assert(ret == a + 3);
+    }
+    {
+      struct S { int check; int other; };
+      S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+      auto ret = std::ranges::lower_bound(a, 4, {}, &S::check);
+      assert(ret == a + 3);
+    }
+  }
+
+  { // check that std::invoke is used for the predicate
+    struct S {
+      int check;
+      int other;
+
+      constexpr bool compare(const S& s) const {
+        return check < s.check;
+      }
+    };
+    {
+      S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+      auto ret = std::ranges::lower_bound(a, a + 6, S{4, 0}, &S::compare);
+      assert(ret == a + 3);
+    }
+    {
+      S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+      auto ret = std::ranges::lower_bound(a, S{4, 0}, &S::compare);
+      assert(ret == a + 3);
+    }
+  }
+
+  { // check that an empty range works
+    {
+      std::array<int, 0> a;
+      auto ret = std::ranges::lower_bound(a.begin(), a.end(), 1);
+      assert(ret == a.end());
+    }
+    {
+      std::array<int, 0> a;
+      auto ret = std::ranges::lower_bound(a, 1);
+      assert(ret == a.end());
+    }
+  }
+
+  { // check that ranges::dangling is returned
+    [[maybe_unused]] std::same_as<std::ranges::dangling> auto ret = std::ranges::lower_bound(std::array{1, 2}, 1);
+  }
+
+  { // check that an iterator is returned with a borrowing range
+    int a[] = {1, 2, 3};
+    std::same_as<int*> auto ret = std::ranges::lower_bound(std::views::all(a), 1);
+    assert(ret == a);
+  }
+
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}
diff --git a/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/upper.bound/ranges.upper_bound.pass.cpp b/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/upper.bound/ranges.upper_bound.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/algorithms/alg.sorting/alg.binary.search/upper.bound/ranges.upper_bound.pass.cpp
@@ -0,0 +1,272 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-has-no-incomplete-ranges
+
+// template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
+//          indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
+//   constexpr I ranges::upper_bound(I first, S last, const T& value, Comp comp = {}, Proj proj = {});
+// template<forward_range R, class T, class Proj = identity,
+//          indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
+//            ranges::less>
+//   constexpr borrowed_iterator_t<R>
+//     ranges::upper_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <ranges>
+
+#include "almost_satisfies_types.h"
+#include "test_iterators.h"
+
+struct NotLessThanComparable {};
+
+template <class It, class Sent = It>
+concept HasUpperBoundIt = requires(It it, Sent sent) { std::ranges::upper_bound(it, sent, 1); };
+
+static_assert(HasUpperBoundIt<int*>);
+static_assert(!HasUpperBoundIt<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>);
+static_assert(!HasUpperBoundIt<ForwardIteratorNotDerivedFrom>);
+static_assert(!HasUpperBoundIt<ForwardIteratorNotIncrementable>);
+static_assert(!HasUpperBoundIt<NotLessThanComparable*>);
+
+template <class Range>
+concept HasUpperBoundR = requires(Range range) { std::ranges::upper_bound(range, 1); };
+
+static_assert(HasUpperBoundR<std::array<int, 1>>);
+static_assert(!HasUpperBoundR<ForwardRangeNotDerivedFrom>);
+static_assert(!HasUpperBoundR<ForwardRangeNotIncrementable>);
+static_assert(!HasUpperBoundR<UncheckedRange<NotLessThanComparable*>>);
+
+template <class Pred>
+concept HasUpperBoundPred = requires(int* it, Pred pred) {std::ranges::upper_bound(it, it, 1, pred); };
+
+static_assert(HasUpperBoundPred<std::ranges::less>);
+static_assert(!HasUpperBoundPred<IndirectUnaryPredicateNotCopyConstructible>);
+static_assert(!HasUpperBoundPred<IndirectUnaryPredicateNotPredicate>);
+
+template <class It>
+constexpr void test_iterators() {
+  { // simple test
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      std::same_as<It> auto ret = std::ranges::upper_bound(It(a), It(a + 6), 3);
+      assert(base(ret) == a + 3);
+    }
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      std::same_as<It> auto ret = std::ranges::upper_bound(range, 3);
+      assert(base(ret) == a + 3);
+    }
+  }
+
+  { // check that the predicate is used
+    {
+      int a[] = {6, 5, 4, 3, 2, 1};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 6), 2, std::ranges::greater{});
+      assert(base(ret) == a + 5);
+    }
+    {
+      int a[] = {6, 5, 4, 3, 2, 1};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      auto ret = std::ranges::upper_bound(range, 2, std::ranges::greater{});
+      assert(base(ret) == a + 5);
+    }
+  }
+
+  { // check that the projection is used
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 6), 0, {}, [](int i) { return i - 3; });
+      assert(base(ret) == a + 3);
+    }
+    {
+      int a[] = {1, 2, 3, 4, 5, 6};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      auto ret = std::ranges::upper_bound(range, 0, {}, [](int i) { return i - 3; });
+      assert(base(ret) == a + 3);
+    }
+  }
+
+  { // check that the last upper bound is returned
+    {
+      int a[] = {1, 2, 2, 2, 3};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 5), 2);
+      assert(base(ret) == a + 4);
+    }
+    {
+      int a[] = {1, 2, 2, 2, 3};
+      auto range = std::ranges::subrange(It(a), It(a + 5));
+      auto ret = std::ranges::upper_bound(range, 2);
+      assert(base(ret) == a + 4);
+    }
+  }
+
+  { // check that end is returned if all elements compare less than
+    {
+      int a[] = {1, 2, 3, 4};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 4), 5);
+      assert(base(ret) == a + 4);
+    }
+    {
+      int a[] = {1, 2, 3, 4};
+      auto range = std::ranges::subrange(It(a), It(a + 4));
+      auto ret = std::ranges::upper_bound(range, 5);
+      assert(base(ret) == a + 4);
+    }
+  }
+
+  { // check that the first element is returned if no element compares less than
+    {
+      int a[] = {1, 2, 3, 4};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 4), 0);
+      assert(base(ret) == a);
+    }
+    {
+      int a[] = {1, 2, 3, 4};
+      auto range = std::ranges::subrange(It(a), It(a + 4));
+      auto ret = std::ranges::upper_bound(range, 0);
+      assert(base(ret) == a);
+    }
+  }
+
+  { // check that a single element works
+    {
+      int a[] = {1};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 1), 1);
+      assert(base(ret) == a + 1);
+    }
+    {
+      int a[] = {1};
+      auto range = std::ranges::subrange(It(a), It(a + 1));
+      auto ret = std::ranges::upper_bound(range, 1);
+      assert(base(ret) == a + 1);
+    }
+  }
+
+  { // check that an even number of elements works
+    {
+      int a[] = {1, 3, 6, 6, 7, 8};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 6), 6);
+      assert(base(ret) == a + 4);
+    }
+    {
+      int a[] = {1, 3, 6, 6, 7, 8};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      auto ret = std::ranges::upper_bound(range, 6);
+      assert(base(ret) == a + 4);
+    }
+  }
+
+  { // check that an odd number of elements works
+    {
+      int a[] = {1, 3, 6, 6, 7};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 5), 6);
+      assert(base(ret) == a + 4);
+    }
+    {
+      int a[] = {1, 3, 6, 6, 7};
+      auto range = std::ranges::subrange(It(a), It(a + 5));
+      auto ret = std::ranges::upper_bound(range, 6);
+      assert(base(ret) == a + 4);
+    }
+  }
+
+  { // check that it works when all but the searched for element are equal
+    {
+      int a[] = {1, 6, 6, 6, 6, 6};
+      auto ret = std::ranges::upper_bound(It(a), It(a + 6), 1);
+      assert(base(ret) == a + 1);
+    }
+    {
+      int a[] = {1, 6, 6, 6, 6, 6};
+      auto range = std::ranges::subrange(It(a), It(a + 6));
+      auto ret = std::ranges::upper_bound(range, 1);
+      assert(base(ret) == a + 1);
+    }
+  }
+}
+
+constexpr bool test() {
+  test_iterators<int*>();
+  test_iterators<forward_iterator<int*>>();
+  test_iterators<bidirectional_iterator<int*>>();
+  test_iterators<random_access_iterator<int*>>();
+  test_iterators<contiguous_iterator<int*>>();
+
+  { // check that std::invoke is used for the projections
+    {
+      struct S { int check; int other; };
+      S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+      auto ret = std::ranges::upper_bound(a, a + 6, 4, {}, &S::check);
+      assert(ret == a + 4);
+    }
+    {
+      struct S { int check; int other; };
+      S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+      auto ret = std::ranges::upper_bound(a, 4, {}, &S::check);
+      assert(ret == a + 4);
+    }
+  }
+
+  { // check that std::invoke is used for the predicate
+    struct S {
+      int check;
+      int other;
+
+      constexpr bool compare(const S& s) const {
+        return check < s.check;
+      }
+    };
+    {
+      S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+      auto ret = std::ranges::upper_bound(a, a + 6, S{4, 0}, &S::compare);
+      assert(ret == a + 4);
+    }
+    {
+      S a[] = {{1, 6}, {2, 5}, {3, 4}, {4, 3}, {5, 2}, {6, 1}};
+      auto ret = std::ranges::upper_bound(a, S{4, 0}, &S::compare);
+      assert(ret == a + 4);
+    }
+  }
+
+  { // check that an empty range works
+    {
+      std::array<int, 0> a;
+      auto ret = std::ranges::upper_bound(a.begin(), a.end(), 1);
+      assert(ret == a.end());
+    }
+    {
+      std::array<int, 0> a;
+      auto ret = std::ranges::upper_bound(a, 1);
+      assert(ret == a.end());
+    }
+  }
+
+  { // check that ranges::dangling is returned
+    [[maybe_unused]] std::same_as<std::ranges::dangling> auto ret = std::ranges::upper_bound(std::array{1, 2}, 1);
+  }
+
+  { // check that an iterator is returned with a borrowing range
+    int a[] = {1, 2, 3};
+    std::same_as<int*> auto ret = std::ranges::upper_bound(std::views::all(a), 1);
+    assert(ret == a + 1);
+  }
+
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}
diff --git a/libcxx/test/std/library/description/conventions/customization.point.object/niebloid.compile.pass.cpp b/libcxx/test/std/library/description/conventions/customization.point.object/niebloid.compile.pass.cpp
--- a/libcxx/test/std/library/description/conventions/customization.point.object/niebloid.compile.pass.cpp
+++ b/libcxx/test/std/library/description/conventions/customization.point.object/niebloid.compile.pass.cpp
@@ -63,7 +63,7 @@
 //static_assert(test(std::ranges::adjacent_find, a));
 //static_assert(test(std::ranges::all_of, a, odd));
 //static_assert(test(std::ranges::any_of, a, odd));
-//static_assert(test(std::ranges::binary_search, a, 42));
+static_assert(test(std::ranges::binary_search, a, 42));
 //static_assert(test(std::ranges::clamp, 42, 42, 42));
 //static_assert(test(std::ranges::copy, a, a));
 //static_assert(test(std::ranges::copy_backward, a, a));
@@ -94,7 +94,7 @@
 //static_assert(test(std::ranges::is_sorted, a));
 //static_assert(test(std::ranges::is_sorted_until, a));
 //static_assert(test(std::ranges::lexicographical_compare, a, a));
-//static_assert(test(std::ranges::lower_bound, a, 42));
+static_assert(test(std::ranges::lower_bound, a, 42));
 //static_assert(test(std::ranges::make_heap, a));
 //static_assert(test(std::ranges::max, a));
 static_assert(test(std::ranges::max_element, a));
@@ -146,7 +146,7 @@
 //static_assert(test(std::ranges::transform, a, a, triple));
 //static_assert(test(std::ranges::unique, a));
 //static_assert(test(std::ranges::unique_copy, a, a));
-//static_assert(test(std::ranges::upper_bound, a, 42));
+static_assert(test(std::ranges::upper_bound, a, 42));
 
 // [memory.syn]
 
diff --git a/libcxx/test/support/almost_satisfies_types.h b/libcxx/test/support/almost_satisfies_types.h
--- a/libcxx/test/support/almost_satisfies_types.h
+++ b/libcxx/test/support/almost_satisfies_types.h
@@ -139,4 +139,43 @@
 static_assert(!std::movable<WeaklyIncrementableNotMovable>);
 static_assert(!std::weakly_incrementable<WeaklyIncrementableNotMovable>);
 
+// almost a forward_iterator
+class ForwardIteratorNotDerivedFrom {
+public:
+  using difference_type = long;
+  using value_type = int;
+  using iterator_category = std::input_iterator_tag;
+
+  ForwardIteratorNotDerivedFrom& operator++();
+  ForwardIteratorNotDerivedFrom operator++(int);
+  const int& operator*() const;
+  bool operator==(const ForwardIteratorNotDerivedFrom&) const = default;
+};
+
+using ForwardRangeNotDerivedFrom = UncheckedRange<ForwardIteratorNotDerivedFrom>;
+
+static_assert(std::input_iterator<ForwardIteratorNotDerivedFrom>);
+static_assert(std::incrementable<ForwardIteratorNotDerivedFrom>);
+static_assert(std::sentinel_for<ForwardIteratorNotDerivedFrom, ForwardIteratorNotDerivedFrom>);
+static_assert(!std::forward_iterator<ForwardIteratorNotDerivedFrom>);
+
+class ForwardIteratorNotIncrementable {
+public:
+  using difference_type = long;
+  using value_type = int;
+  using iterator_category = std::forward_iterator_tag;
+
+  ForwardIteratorNotIncrementable& operator++();
+  int operator++(int);
+  const int& operator*() const;
+  bool operator==(const ForwardIteratorNotIncrementable&) const = default;
+};
+
+using ForwardRangeNotIncrementable = UncheckedRange<ForwardIteratorNotIncrementable>;
+
+static_assert(std::input_iterator<ForwardIteratorNotIncrementable>);
+static_assert(!std::incrementable<ForwardIteratorNotIncrementable>);
+static_assert(std::sentinel_for<ForwardIteratorNotIncrementable, ForwardIteratorNotIncrementable>);
+static_assert(!std::forward_iterator<ForwardIteratorNotIncrementable>);
+
 #endif // ALMOST_SATISFIES_TYPES_H