Developer tool
JSON Compare
Paste two JSON values to compare them side by side. Both inputs are formatted consistently before the diff, so layout differences don't appear as changes.
Compare JSON changes
Side-by-side comparison helps when an API response changed, a config file was edited, or two webhook examples need a final check. Both inputs are parsed first, so invalid JSON is caught before the diff appears.
After parsing, both sides are beautified with the same indentation and differing lines are highlighted for a quick review.
Both JSON values stay in your browser — nothing is sent to a server, which makes it safe to compare payloads that include tokens, environment credentials, or user data.
Practical examples
- Compare an old API response with a new response from staging.
- Review a changed JSON configuration before committing it.
- Check whether a fixture update changed values or only formatting.
- Verify that a webhook payload from a test event matches the format the handler expects.
- Find breaking changes between two API versions by comparing a sample response from each.
Related JSON tools
Validate each side with the JSON Validator, inspect nested fields with the JSON Viewer, or prepare compact output with the JSON Minifier.
FAQ
How does JSON Compare find differences?
It parses both inputs, formats them consistently, then highlights lines that differ side by side.
Does key order matter?
Object key order is preserved from the parsed input, so differently ordered objects may appear different.
Can it compare invalid JSON?
No. Both inputs must parse as valid JSON before the diff is shown.
Is either JSON value uploaded?
No. Parsing, formatting, and comparison run locally in your browser.
What is it best for?
API responses, webhook payloads, config files, test fixture changes, and spotting breaking changes between two API versions.
Can I compare large JSON payloads?
The comparison runs entirely in your browser, so large API responses and nested JSON objects can be reviewed without uploading data to a server. Performance may vary depending on browser memory and device resources.
Can I use this to find breaking changes between two API versions?
Yes. Paste a sample response from the old version on one side and the new version on the other. Added fields, removed keys, and changed values each show up as highlighted lines.