JSONBlitz Compare is a free, privacy-first, client-side JSON diff tool. Paste two JSON documents and get a semantic structural diff — ignoring key order, matching array elements by identity key, and showing added, removed, and modified fields with three-state color coding. Nothing ever leaves your browser.
Unlike text-based diff tools, JSONBlitz Compare parses both documents first and compares the data structure. Objects with the same keys and values in different order are correctly identified as identical.
When arrays contain objects with a shared id, _id, uuid, key, sku, or name field, JSONBlitz Compare matches elements by that key value instead of position. Reordering an array no longer produces a flood of false positives.
Export the diff as a standard RFC 6902 JSON Patch document — a machine-readable list of add, remove, and replace operations. Useful for applying diffs programmatically or as input to JSON Patch libraries.
Add timestamp, requestId, updatedAt, or any other field to the ignore list. The comparison re-runs instantly. Wildcard patterns like *.updatedAt match the field at any depth. Useful for comparing API responses that include request-specific metadata.