Diff JSON
Diff structurel entre deux documents JSON — clés ajoutées, supprimées, modifiées et changements de valeur côte à côte.
Saisissez une entrée ci-dessus pour voir le résultat.
What is this for?
A plain-text diff on JSON tells you which lines changed; a structural diff tells you which data points changed. They're often very different — a re-formatted document with no semantic change is "every line different" to a text diff but "no changes" here. This tool walks both JSON trees and reports each path where they differ, using RFC 6901 JSON Pointer syntax (/users/0/name) so the output is unambiguous regardless of formatting.
When to use it
- Comparing two API responses to see what actually changed in a release, ignoring whitespace/key-order noise.
- Diffing config files before/after a migration to confirm only the intended fields moved.
- Generating an RFC 6902 JSON Patch document to ship to a system that supports it (PATCH endpoints, JSON-Merge-Patch fallbacks).
- Eyeballing two test fixtures to see what makes one fail when the other passes.
Common gotchas
- Array compare mode matters. "By index" reports an inserted element as remove+add for everything after it. "By value" treats arrays as sets, missing genuine reorderings. Pick the one that matches how your data is meant to be ordered.
- Number-vs-string isn't structural.
{"id": 1}and{"id": "1"}show as a change because the types differ. Normalise types before diffing if that matters. - RFC 6902 is a one-way patch, not a merge. Apply it with a real RFC 6902 implementation, not by string-replacement.
- Big trees get noisy. If the diff is hundreds of operations long, you're probably comparing two unrelated documents — re-check the inputs.