JSON Array Comparator
Compare two JSON lists or objects, detect differences, and use ergonomic filters.
About: JSON Array Comparator
This JSON comparator puts two lists side by side and shows what only exists on one side, what both share, and how similar they are. Use it to check that one export holds the same IDs as another, find entries that went missing after a migration, or compare two API responses. With arrays of objects, you pick which shared keys to compare. Everything is computed in your browser, so the data never leaves your machine.
Features
- Compares arrays of plain values (strings, numbers, booleans) by membership, so order and duplicates don't affect the result.
- Detects the keys two objects have in common and compares only the keys you select.
- Options to ignore case and accents, plus a strict mode that tells the number 1 apart from the string "1".
- Split or unified diff with added and removed counts, a similarity percentage and a search filter.
- Each list can be renamed and browsed as a tree, with search across keys and values.
How to use it
- Paste your first JSON into the left panel and the second into the right panel, renaming them if you like.
- Open the advanced options to ignore case or accents, or to turn off strict comparison.
- Click Analyze to get the diff, or pick the common keys to compare when your lists contain objects.
- Filter the diff or switch between split and unified views to read the differences.
Questions about usage
No. The comparison runs entirely in your browser and nothing is uploaded. The content of both panels is stored in the page URL, so opening the same link later brings back the same comparison.
No. For arrays of plain values, the tool checks whether each value is present, not where it sits. Duplicates are merged. The diff lists values in alphabetical order and marks the ones found only in A or only in B.
Paste both and click Analyze: the tool lists the keys found in the first object on each side. Tick the ones you care about and run the comparison on those keys. You get the number of equal keys, a similarity score and a line diff of the values that differ.