diff --git a/llvm/utils/TableGen/jupyter/LLVM_TableGen.ipynb b/llvm/utils/TableGen/jupyter/LLVM_TableGen.ipynb
--- a/llvm/utils/TableGen/jupyter/LLVM_TableGen.ipynb
+++ b/llvm/utils/TableGen/jupyter/LLVM_TableGen.ipynb
@@ -316,6 +316,50 @@
     "%args\n",
     "class Thing <int A, int B> {}"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "9e04969a",
+   "metadata": {},
+   "source": [
+    "The `%json` magic can be used to show the records as JSON. This is equivalent to `%args --dump-json` with the added benefit that we format the output for you."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "id": "21d3283b",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "{\n",
+      "    \"!instanceof\": {\n",
+      "        \"Root\": [\n",
+      "            \"thing\"\n",
+      "        ]\n",
+      "    },\n",
+      "    \"!tablegen_json_version\": 1,\n",
+      "    \"thing\": {\n",
+      "        \"!anonymous\": false,\n",
+      "        \"!fields\": [],\n",
+      "        \"!name\": \"thing\",\n",
+      "        \"!superclasses\": [\n",
+      "            \"Root\"\n",
+      "        ]\n",
+      "    }\n",
+      "}"
+     ]
+    }
+   ],
+   "source": [
+    "%reset\n",
+    "%json\n",
+    "class Root {}\n",
+    "def thing : Root {}"
+   ]
   }
  ],
  "metadata": {
diff --git a/llvm/utils/TableGen/jupyter/LLVM_TableGen.md b/llvm/utils/TableGen/jupyter/LLVM_TableGen.md
--- a/llvm/utils/TableGen/jupyter/LLVM_TableGen.md
+++ b/llvm/utils/TableGen/jupyter/LLVM_TableGen.md
@@ -150,3 +150,30 @@
     class Thing <int A, int B> {}
                             ^
 
+
+The `%json` magic can be used to show the records as JSON. This is equivalent to `%args --dump-json` with the added benefit that we format the output for you.
+
+
+```tablegen
+%reset
+%json
+class Root {}
+def thing : Root {}
+```
+
+    {
+        "!instanceof": {
+            "Root": [
+                "thing"
+            ]
+        },
+        "!tablegen_json_version": 1,
+        "thing": {
+            "!anonymous": false,
+            "!fields": [],
+            "!name": "thing",
+            "!superclasses": [
+                "Root"
+            ]
+        }
+    }
diff --git a/llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py b/llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py
--- a/llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py
+++ b/llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py
@@ -2,6 +2,7 @@
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
+import json
 import os
 import shutil
 import subprocess
@@ -20,6 +21,7 @@
     The supported magic is:
     * %args - to set the arguments passed to llvm-tblgen.
     * %reset - to reset the cached code and magic state.
+    * %json - to emit records as JSON.
 
     These are "cell magic" meaning it applies to the whole cell. Therefore
     it must be the first line, or part of a run of magic lines starting
@@ -126,24 +128,24 @@
 
         return "\n".join(code_lines), magic
 
-    def get_code_and_args(self, new_code):
-        """Get the code that do_execute should use, taking into account
-        the code from any cached cells.
-
-        Returns the code to compile and the arguments to use to do so.
+    def get_code_and_magic(self, new_code):
+        """Get the code that do_execute should use, and the magic
+        to run it with.
 
         >>> k._previous_code = ""
         >>> k._previous_magic = {}
-        >>> k.get_code_and_args("")
-        ('', [])
-        >>> k.get_code_and_args("%args 1\\nSome code")
-        ('Some code', ['1'])
-        >>> k.get_code_and_args("%args 2\\nSome more code")
-        ('Some code\\nSome more code', ['2'])
-        >>> k.get_code_and_args("%reset\\n%args 3 4\\nSome new code")
-        ('Some new code', ['3', '4'])
-        >>> k.get_code_and_args("%reset\\nSome new code")
-        ('Some new code', [])
+        >>> k.get_code_and_magic("")
+        ('', {})
+        >>> k.get_code_and_magic("%args 1\\nSome code")
+        ('Some code', {'args': ['1']})
+        >>> k.get_code_and_magic("%args 2\\nSome more code")
+        ('Some code\\nSome more code', {'args': ['2']})
+        >>> k.get_code_and_magic("")
+        ('Some code\\nSome more code\\n', {'args': ['2']})
+        >>> k.get_code_and_magic("%reset\\n%args 3 4\\nSome new code")
+        ('Some new code', {'args': ['3', '4']})
+        >>> k.get_code_and_magic("%reset\\nSome new code")
+        ('Some new code', {})
         """
         new_code, new_magic = self.get_magic(new_code)
 
@@ -155,13 +157,17 @@
             self._previous_code += ("\n" if self._previous_code else "") + new_code
             self._previous_magic.update(new_magic)
 
-        return self._previous_code, self._previous_magic.get("args", [])
+        return self._previous_code, self._previous_magic
 
     def do_execute(
         self, code, silent, store_history=True, user_expressions=None, allow_stdin=False
     ):
         """Execute user code using llvm-tblgen binary."""
-        all_code, args = self.get_code_and_args(code)
+        all_code, magic = self.get_code_and_magic(code)
+
+        args = magic.get("args", [])
+        if magic.get("json") is not None:
+            args.append("--dump-json")
 
         with tempfile.TemporaryFile("w+") as f:
             f.write(all_code)
@@ -180,8 +186,15 @@
                     self.iopub_socket, "stream", {"name": "stderr", "text": got.stderr}
                 )
             else:
+                out = got.stdout
+                if magic.get("json") is not None:
+                    j = json.loads(out)
+                    out = json.dumps(j, indent=4)
+
                 self.send_response(
-                    self.iopub_socket, "stream", {"name": "stdout", "text": got.stdout}
+                    self.iopub_socket,
+                    "stream",
+                    {"name": "stdout", "text": out},
                 )
 
         return {