Structural diff of two JSON objects — highlights added, removed, and changed keys.
Compare two JSON objects and instantly see what changed. JSON Diff produces a structural diff that highlights added keys, removed keys, and modified values — no matter how deeply nested the data. Everything runs entirely in your browser, so your data never leaves your device.
Paste the Left JSON
Drop your original JSON object (or array) into the Left pane. Any valid JSON works — nested objects, arrays, primitives.
Paste the Right JSON
Paste the updated version into the Right pane. Use the Swap button to flip the two sides if needed.
Compare
Click Compare to see a color-coded structural diff. Added keys are green, removed keys are red, and modified values show both the old and new value side by side.
No. Both JSON values are parsed and diffed entirely in your browser using JavaScript. Nothing is uploaded, logged, or stored.
A text diff compares line-by-line, so re-ordering keys or reformatting whitespace shows up as a massive diff. JSON Diff parses both sides and compares the structure, so it ignores key order and formatting — you only see real data changes.
Yes. Arrays are compared element-by-element, and moved elements are detected as moves rather than a separate add + remove.
You'll get a clear error message pointing to which side (Left or Right) failed to parse, along with the parser's reason. Fix the syntax and click Compare again.
There's no hard limit — it depends on your browser's memory. JSON files up to several megabytes typically diff without issue.