Diff two JSON docs by structure, not by text.
Paste two JSON documents and see exactly what was added, removed and changed — matched by key, so reordered keys and reformatted whitespace don't masquerade as differences. Get the change list, the summary counts, and a ready-to-apply RFC 6902 patch. It all happens in your browser — nothing is uploaded.
A — original
B — changed
FAQ
Is my data sent anywhere?+
No. Both JSON documents are parsed and compared entirely in your browser — they are never sent to a server. We count anonymous, aggregate usage on our own server (a page view, that a diff was run) — never your JSON, its contents, or the patch we produce.
Why is this better than a text diff?+
A text diff compares characters, so it lights up when nothing meaningful changed — a key moved, the file was re-indented, or a serializer ordered things differently. This tool parses both sides and compares the data: object keys are matched by name regardless of order or whitespace, and only real structural changes (added, removed, or replaced values) are reported, each with its JSON Pointer path. The result also converts straight to an RFC 6902 JSON Patch you can apply elsewhere.
How are arrays compared?+
Arrays are compared by index: element 0 against element 0, and so on, so a value that changed in place is reported as a replace at that index. Reordering or inserting an item near the front therefore shows as several positional changes rather than a single move. Smarter array handling — matching elements by an id key, three-way merges, and schema-aware diffs — is on the Pro roadmap. This core diff is free, with no login.