JSON Diff
Compare two JSON documents and see what changed.
🔒 Runs entirely in your browser — nothing is uploaded.
✅ No differences
How JSON Diff works
How does the JSON diff comparison work?
Both inputs are parsed and re-serialized with JSON.stringify(value, null, 2) so they share the same formatting, then compared line by line using the same longest-common-subsequence algorithm classic tools like diff and git diff use. Lines only in JSON A are marked removed, lines only in JSON B are marked added, and a blank placeholder is inserted on the other side so both columns stay vertically aligned.
What is this useful for?
It is good for comparing two versions of an API response or config file side by side and immediately seeing which lines actually changed between requests or deployments, the same way you would read a git diff.
What happens if a key just moved instead of changed?
The tool specifically looks for matching "key": names on both sides before falling back to plain text similarity, so a field that was reordered - even a field whose value also changed at the same time - still lands on one row with just the differing part highlighted, instead of showing as an unrelated remove-and-add pair.