JSON Diff Checker
Compare two JSON documents and see exactly what was added, removed, or changed — ignoring key order and formatting differences.
🔒 Processed locally in your browser
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How to use
- Paste your original JSON into the "JSON A" box on the left (or top, on mobile).
- Paste the JSON you want to compare it against into the "JSON B" box on the right (or below it, on mobile).
- The diff result updates live underneath as soon as both boxes contain valid JSON — there's no button to press.
- Each difference is listed with its path, an Added/Removed/Changed label, and the before and/or after value.
Features
- Structural (semantic) diff, not a text diff — key order and formatting never trigger false differences
- Reports added, removed, and changed values using clear dot/bracket path notation like user.address[0].city
- Updates live as you type or paste — no button to press
- Shows a clear parse-error message for invalid JSON instead of crashing
- 100% client-side — your JSON never leaves your browser
Frequently asked questions
How is this different from a regular text diff?
A text diff compares JSON line by line, so it would flag every line as different if key order or indentation changes, even when the underlying data is identical. This tool parses both documents and compares the actual data structure, so it only reports real differences in values, and ignores key order and formatting entirely.
What do "added", "removed", and "changed" mean?
"Added" means a path exists in JSON B but not JSON A. "Removed" means a path exists in JSON A but not JSON B. "Changed" means the path exists in both, but the value is different (including when the type differs, like a number in A versus a string in B).
How are array elements compared?
Arrays are compared index by index. If an element at the same index differs, it's reported as changed at that index's path (e.g. tags[2]). If one array is longer, the extra trailing elements are reported as added or removed.
Does my JSON get uploaded anywhere?
No. Both documents are parsed and compared entirely in your browser and are never sent to a server or stored anywhere.
What happens if my JSON is invalid?
The tool shows a clear parse-error message under the box with the problem instead of crashing, so you can fix the syntax and try again.