Field-level JSON comparison
Find added, removed, changed, and type-mismatched fields with their exact JSON paths.
Public HTTPS APIs only · Requests are not saved
Free REST API response comparator
Compare two API responses side by side.
Find JSON field, value, type, status code, body, and response-time differences before release.
AGET
Environment A
Baseline or current API
Headers & body
BGET
Environment B
Candidate or migrated API
Headers & body
Ready to compare
Run the pre-filled sample, or replace both URLs with your own endpoints.
Free API testing tool
Compare REST API responses before you release
API Comparator sends the same request to two public HTTPS endpoints and shows the differences that matter during migrations, upgrades, regression testing, and environment validation.
Status, body, and timing checks
Compare HTTP status codes, response bodies, and request duration in one report.
No saved request history
Comparison requests are processed for the current run and are not stored as a user history.
When an API response comparison helps
- Validating a monolith-to-microservice migration
- Comparing development, test, and production-like environments
- Checking backward compatibility after an API change
- Finding response-time or payload regressions
Continue testing your API
Use the JSON test data generator to create payloads, or read the step-by-step API response comparison guide.
If a request fails, the online log and stack trace explainer can turn common Java, Spring, Kubernetes, Node.js, and Python errors into practical next steps.
API comparison questions
What does API Comparator check?
It checks status codes, response bodies, JSON field paths, values, data types, and request duration for two endpoints.
Can I compare POST or PUT requests?
Yes. Select POST, PUT, or PATCH and add JSON headers and request bodies for both environments.
Does API Comparator store my requests?
No request history is saved. Use only endpoints and test data that you are authorized to send over the public internet.