Compare JSON / YAML — QA & Testing
Compare JSON and YAML by their data, not their text — diff a JSON file straight against a YAML one and see every value that differs. Formatting and key order ignored. Free, private, in-browser.
How to compare json / yaml
- Paste the actual API response on the left — JSON, YAML, or a JavaScript object literal. The format is detected and validated automatically.
- Paste the expected payload or fixture on the right. The two sides don't have to be the same format — check a JSON response against a YAML fixture.
- Keep 'Data' mode on to diff the underlying values, ignoring formatting and key order — or switch to 'Syntax' to assert on the exact text.
Key features
- Compares by data, not text — an unordered or reformatted response still matches
- Differences highlighted live as you type, value by value
- JavaScript object literals ({ x: 2 }) diffed as data alongside strict JSON
- Convert both sides to JSON or YAML in one click, or auto-beautify on the fly
- Runs entirely in your browser — nothing is uploaded. Free, no account
Common uses
- Compare an actual API response against the expected fixture
- Check a JSON response against a YAML fixture without converting either by hand
- Diff two responses across environments to catch a regression
- Verify a mock matches the real endpoint's payload before shipping
Frequently asked questions
How do I compare json / yaml online?
Paste the actual API response on the left — JSON, YAML, or a JavaScript object literal. The format is detected and validated automatically. Paste the expected payload or fixture on the right. The two sides don't have to be the same format — check a JSON response against a YAML fixture. Keep 'Data' mode on to diff the underlying values, ignoring formatting and key order — or switch to 'Syntax' to assert on the exact text.
Are my files private when I use this tool?
Yes. All comparison runs locally in your browser. Your files never leave your device and are never sent to any server — not a policy promise, but an architectural fact. There is no server receiving your data.
No AI means no hallucinations
Compare Files uses a deterministic, logic-based engine — not a language model. It reports every change that is actually in your files, and never invents one.
Your files never leave your device. Everything runs in your browser — no uploads, nothing stored.
No AI, so no hallucinations. A deterministic engine reports every real change and never invents one.
No upload, no server wait. Comparisons run locally and keep working offline once the page has loaded.