JSON Compare
Compare two JSON objects side-by-side. Instantly spot differences in API responses, configs, and data structures.
JSON compare — find differences instantly
A JSON compare tool helps you quickly spot differences between two JSON objects. FormatList's free online JSON diff viewer shows side-by-side comparison with color-coded additions and removals.
Why compare JSON?
- API development — compare request/response payloads between API versions.
- Debugging — find what changed in JSON configurations or data structures.
- Code review — verify JSON changes before merging to production.
- Data migration — compare JSON exports to validate transformations.
JSON compare FAQ
How does the JSON compare tool work?
It parses both JSON inputs, formats them consistently, and uses Monaco's built-in diff editor to show a side-by-side comparison with color-coded additions (green) and removals (red).
Does it ignore key order?
Yes. Both JSON objects are parsed and re-stringified with sorted keys before comparison, so structural differences are highlighted — not cosmetic ordering changes.
Can I compare large JSON files?
Yes. The Monaco editor handles large files efficiently. However, for extremely large files, performance may vary depending on your browser and device.
Is my data sent to a server?
No. All comparison happens locally in your browser. Your JSON data never leaves your computer.
Can I copy the diff results?
Yes. Click 'Copy diff' in the toolbar to copy the comparison result as a text diff to your clipboard.
Related JSON tools
Format, validate, repair, compare, escape, and transform JSON with these browser-based tools.