Does it handle different key order?

Yes — toggle 'Sort keys' on (default). Two JSON objects with the same keys in different order will diff as identical. This is essential when comparing API responses since JSON object key order isn't guaranteed.

Does it work on nested arrays?

Yes. The diff is line-by-line after pretty-printing, so nested arrays and objects show their differences with proper indentation. Arrays are diffed in order — a reordered array WILL show as changed (intentional, since array order is part of JSON's spec).

Does it work for very large JSON?

Up to roughly 1-2MB in each pane runs smoothly. Beyond that, browser performance degrades. For huge files, split them into smaller meaningful chunks.

What if my JSON is broken?

Each side shows its parse error inline (with the specific message and position). Fix the syntax and the diff regenerates automatically. For broken JSON from LLM responses, try the AI JSON Repair tool first.

Yes. The 'Copy diff' button copies a unified-diff format (lines prefixed with +, -, or space) that pastes cleanly into Slack, GitHub, or a PR description.

JSON Diff & Compare

Paste two JSON snippets and instantly see the structural differences. Toggle 'sort keys' to compare structurally (ignoring key order) — useful when comparing API responses, config files, or data dumps where key order varies. Shows a colored line-by-line diff with added/removed counts and a copyable unified diff. Validates each side independently and shows parse errors inline. Everything runs in your browser.

Left JSON

Right JSON

Sort keys (compare structurally, ignore key order)

+4 -2

Diff

 {
-  "city": "Bethesda",
+  "city": "DC",
+  "joined": "2026-05-18",
   "name": "Saurav",
   "tags": [
     "dev",
-    "ai"
+    "ai",
+    "founder"
   ]
 }

Frequently Asked Questions

Does it handle different key order?: Yes — toggle 'Sort keys' on (default). Two JSON objects with the same keys in different order will diff as identical. This is essential when comparing API responses since JSON object key order isn't guaranteed.
Does it work on nested arrays?: Yes. The diff is line-by-line after pretty-printing, so nested arrays and objects show their differences with proper indentation. Arrays are diffed in order — a reordered array WILL show as changed (intentional, since array order is part of JSON's spec).
Does it work for very large JSON?: Up to roughly 1-2MB in each pane runs smoothly. Beyond that, browser performance degrades. For huge files, split them into smaller meaningful chunks.
What if my JSON is broken?: Each side shows its parse error inline (with the specific message and position). Fix the syntax and the diff regenerates automatically. For broken JSON from LLM responses, try the AI JSON Repair tool first.
Can I copy the diff?: Yes. The 'Copy diff' button copies a unified-diff format (lines prefixed with +, -, or space) that pastes cleanly into Slack, GitHub, or a PR description.

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About JSON Diff & Compare

Free online JSON diff tool. Compare two JSON objects side-by-side with structural sorting. See added, removed, and changed keys with colored output. No signup, browser-only. This tool runs entirely in your browser, so your content is not sent to a server. MarkdownMe provides free, fast, and reliable Markdown tools for developers, writers, and anyone who works with Markdown.