Why can't I just diff two JSON responses in my editor?

You can, but a text diff reports key order and whitespace as changes, and two servers rarely serialise in the same order. Comparing decoded structures means only real differences show up, each with the path that reached it.

Every comparison shows differences in timestamps. Can I ignore those?

Yes — that is what the ignore list is for. Add timestamp, requestId, traceId or whatever your API returns, and they are skipped wherever they appear, at any depth.

Are my API keys stored?

No. Headers are used to make the request and nothing else — they are never logged, never written to disk, and never included in the response you get back. They are also dropped if an endpoint redirects to a different origin, so a token can't follow a 302 somewhere you didn't intend.

Does it follow redirects?

Yes, up to five, and every hop is checked before it is made. Requests to private or internal addresses are refused at the hop rather than only at the URL you typed.

Is array order treated as significant?

By default yes, because JSON arrays are ordered and a reordered list can break a client. There is a switch to ignore order when your API genuinely doesn't guarantee it.

API Response Comparator — Diff Two Endpoints

About API Response Comparator

Point it at two endpoints — staging and production, v1 and v2, before and after a deploy — and it calls both and shows exactly what moved: status code, headers, timing, and a field-by-field diff of the JSON bodies. Because it compares parsed structures rather than text, key order and whitespace don't register as changes, and every difference comes with the JSON path that reached it. Ignore the keys that change on every call — timestamp, requestId, traceId — and what's left is the part you actually care about.

Field-by-field JSON diff with a path for every difference
Status, headers and response time compared side by side
Ignore volatile keys like timestamp and requestId
Send your own method, headers and body on each side

How to compare two API responses

1Paste the two URLs you want to compare.
2Add any headers each side needs — an API key, an Accept header.
3List the keys that change every call, so they stop being noise.
4Run the comparison and read the differences by JSON path.

Frequently asked questions

Why can't I just diff two JSON responses in my editor?: You can, but a text diff reports key order and whitespace as changes, and two servers rarely serialise in the same order. Comparing decoded structures means only real differences show up, each with the path that reached it.
Every comparison shows differences in timestamps. Can I ignore those?: Yes — that is what the ignore list is for. Add timestamp, requestId, traceId or whatever your API returns, and they are skipped wherever they appear, at any depth.
Are my API keys stored?: No. Headers are used to make the request and nothing else — they are never logged, never written to disk, and never included in the response you get back. They are also dropped if an endpoint redirects to a different origin, so a token can't follow a 302 somewhere you didn't intend.
Does it follow redirects?: Yes, up to five, and every hop is checked before it is made. Requests to private or internal addresses are refused at the hop rather than only at the URL you typed.
Is array order treated as significant?: By default yes, because JSON arrays are ordered and a reordered list can break a client. There is a switch to ignore order when your API genuinely doesn't guarantee it.