Developer Utility
JSON Diff Checker
Compare two JSON datasets to find added, removed, and changed values. Useful for checking API responses, configuration files, and test data differences.
JSON input
Enter the original JSON and the changed JSON to compare.
Comparison result
Check added, removed, and changed JSON paths and values.
Enter two JSON datasets and click the compare button.
How JSON comparison works
The result is based on parsed JSON structure, paths, and values rather than plain text comparison.
Fields or array items that exist only in the changed JSON. Useful for checking new API fields or settings.
Fields that existed in the original JSON but disappeared from the changed JSON.
Items with the same path but different values or types. Useful for version, response, and setting changes.
Help
What is JSON Diff Checker?
JSON Diff Checker is a free developer utility for comparing two JSON datasets and finding added, removed, or changed values.
Use it for API response comparison, configuration changes, deployment checks, test result comparison, and frontend-backend data contract reviews.
Features
- Compare two JSON structures
- Classify added, removed, and changed values
- Show object and array paths
- Show type differences for strings, numbers, booleans, null, objects, and arrays
- Format both JSON inputs
- Show summary counts
- Copy results and download a report
Use cases
- Check API response changes
- Compare JSON configuration files before and after edits
- Review backend and frontend data structures
- Compare test data with actual response data
- Check JSON changes before and after deployment
- Find missing fields in complex JSON objects
How are JSON differences displayed?
Differences are displayed by JSON path. For example, when user.name changes, the result shows the path with the before and after values.
Can arrays be compared?
Arrays are compared by index, such as items[0] and items[1]. If array order changes, values may be marked as changed even when the same values exist.
When should I use JSON formatting?
Use formatting to make compressed single-line JSON or poorly indented JSON easier to read.
What does type difference mean?
If a value changes from 1 to "1", it may look similar but the type changed from number to string.
What happens if JSON has syntax errors?
Comparison will not run when JSON syntax is invalid. Check missing quotes, trailing commas, and unclosed braces or brackets.
Can I enter sensitive data?
This tool compares JSON in the browser, but it is still recommended to remove or mask passwords, API keys, tokens, and personal information.