JSON Compare

Two JSON documents can look almost identical and still differ in ways that are hard to spot by eye — an extra field, a boolean flipped, a number changed three levels deep. A JSON diff walks both documents key by key and array index by index, reporting exactly which paths were added, removed, or changed, instead of making you scan two walls of text for the one line that moved.

This matters most when comparing API responses across versions, config files across environments, or a request body against an expected fixture in a test. Key order in an object never changes its meaning, so this tool ignores it — only the actual keys and values are compared.

It runs entirely in your browser: both documents are parsed and diffed locally and never sent anywhere, so it is safe to compare a real API response or config containing internal data.

The result is a flat, readable list of paths — user.address.zip, items[2].price — each tagged as added, removed, or changed, with the old and new value shown inline. Copy the report as plain text to paste into a PR description or a bug report.

1. Paste the original JSON into the left panel and the updated version into the right.
2. A colored, line-by-line view appears automatically as you type — red lines were removed or changed on the left, green lines were added or changed on the right.
3. Use Swap sides to flip which document is treated as the original, or Clear to start over.
4. Press Copy report to put the full diff on your clipboard.