How to diff two api responses to identify changes
- Step 1Capture the before and after API responses — Make the API call in both the old and new environment (or before and after a deployment). Copy the response body JSON from each call.
- Step 2Paste both responses — Paste the old response in the left panel and the new response in the right panel. The tool normalizes whitespace and key order before diffing so cosmetic differences do not appear as changes.
- Step 3Review the diff output — The structured diff shows each change: added fields that consumers may not handle, removed fields that consumers depend on, and changed values that may indicate data migrations or bugs.
- Step 4Document breaking changes — Export the diff as a list of field changes. Use this list to update the API changelog and identify which consumer integrations need updates.
Frequently asked questions
How do I tell if a change is breaking?+
Breaking changes include: removing a required field, changing a field's type (string to number), changing a field name, and removing an array element type. Non-breaking additive changes include: adding a new field (consumers ignoring unknown fields are unaffected) and adding new enum values if the consumer handles unknown values gracefully.
How do I diff large paginated responses efficiently?+
Compare a single item from each paginated response rather than the full response — diff item[0] from the old response against item[0] from the new response. This gives you the structural and value diff for a representative object without comparing hundreds of array elements.
Is the API response data transmitted to JAD Apps?+
No. Diffing runs entirely in your browser. API responses including customer data are never transmitted to JAD Apps servers.
Privacy first
Conversion runs locally in your browser. No file is uploaded — only metadata counters are saved for signed-in dashboard stats.