diff --git a/clang-tools-extra/clangd/ClangdLSPServer.cpp b/clang-tools-extra/clangd/ClangdLSPServer.cpp
--- a/clang-tools-extra/clangd/ClangdLSPServer.cpp
+++ b/clang-tools-extra/clangd/ClangdLSPServer.cpp
@@ -619,9 +619,10 @@
 
   llvm::json::Object Result{
       {{"serverInfo",
-        llvm::json::Object{{"name", "clangd"},
-                           {"version", llvm::formatv("{0} {1}", versionString(),
-                                                     featureString())}}},
+        llvm::json::Object{
+            {"name", "clangd"},
+            {"version", llvm::formatv("{0} {1} {2}", versionString(),
+                                      featureString(), platformString())}}},
        {"capabilities", std::move(ServerCaps)}}};
   if (Opts.Encoding)
     Result["offsetEncoding"] = *Opts.Encoding;
diff --git a/clang-tools-extra/clangd/Features.h b/clang-tools-extra/clangd/Features.h
--- a/clang-tools-extra/clangd/Features.h
+++ b/clang-tools-extra/clangd/Features.h
@@ -19,6 +19,10 @@
 // Returns a version string for clangd, e.g. "clangd 10.0.0"
 std::string versionString();
 
+// Returns the platform triple for clangd, e.g. "x86_64-pc-linux-gnu"
+// May include both the host and target triple if they differ.
+std::string platformString();
+
 // Returns a string describing the compile-time configuration.
 // e.g. mac+debug+asan+grpc
 std::string featureString();
diff --git a/clang-tools-extra/clangd/Features.cpp b/clang-tools-extra/clangd/Features.cpp
--- a/clang-tools-extra/clangd/Features.cpp
+++ b/clang-tools-extra/clangd/Features.cpp
@@ -9,12 +9,26 @@
 #include "Features.h"
 #include "clang/Basic/Version.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/Host.h"
 
 namespace clang {
 namespace clangd {
 
 std::string versionString() { return clang::getClangToolFullVersion("clangd"); }
 
+std::string platformString() {
+  static std::string PlatformString = []() {
+    std::string Host = llvm::sys::getProcessTriple();
+    std::string Target = llvm::sys::getDefaultTargetTriple();
+    if (Host != Target) {
+      Host += "; target=";
+      Host += Target;
+    }
+    return Host;
+  }();
+  return PlatformString;
+}
+
 std::string featureString() {
   return
 #if defined(_WIN32)
diff --git a/clang-tools-extra/clangd/index/remote/Client.cpp b/clang-tools-extra/clangd/index/remote/Client.cpp
--- a/clang-tools-extra/clangd/index/remote/Client.cpp
+++ b/clang-tools-extra/clangd/index/remote/Client.cpp
@@ -74,6 +74,7 @@
     grpc::ClientContext Context;
     Context.AddMetadata("version", versionString());
     Context.AddMetadata("features", featureString());
+    Context.AddMetadata("platform", platformString());
     std::chrono::system_clock::time_point StartTime =
         std::chrono::system_clock::now();
     auto Deadline = StartTime + DeadlineWaitingTime;
diff --git a/clang-tools-extra/clangd/tool/ClangdMain.cpp b/clang-tools-extra/clangd/tool/ClangdMain.cpp
--- a/clang-tools-extra/clangd/tool/ClangdMain.cpp
+++ b/clang-tools-extra/clangd/tool/ClangdMain.cpp
@@ -679,7 +679,8 @@
   llvm::sys::SetInterruptFunction(&requestShutdown);
   llvm::cl::SetVersionPrinter([](llvm::raw_ostream &OS) {
     OS << versionString() << "\n"
-       << "Features: " << featureString() << "\n";
+       << "Features: " << featureString() << "\n"
+       << "Platform: " << platformString() << "\n";
   });
   const char *FlagsEnvVar = "CLANGD_FLAGS";
   const char *Overview =