About this tool
What is a JSON diff?
A JSON diff compares two JSON documents structurally — not as raw text — and shows added, removed and changed keys, including inside nested objects and arrays. That makes it the right way to review API responses, config changes, or test fixtures.
How to use it
- Paste the original JSON on the left and the modified JSON on the right.
- Differences are highlighted per key path; unchanged branches can be collapsed.
- Both panes validate JSON as you type, with error positions.
Examples
- Comparing staging vs production API responses to spot a renamed field.
- Reviewing a config change: which keys were added, which defaults flipped.
- Checking that a migration preserved every nested value.
Important limitations
- Array order matters by default: reordered arrays show as changes even when the set is identical.
- Huge documents (tens of megabytes) may render slowly; compare focused subtrees instead.
- Semantic equality (1 vs 1.0, key order) depends on JSON semantics, not text.
Privacy
Comparison runs fully in your browser. Pasted JSON — which often contains secrets or personal data — never leaves your device.
Frequently asked questions
How is this different from text diff?
Text diff flags moved commas and reformatting as changes. JSON diff parses both documents and compares the actual data structure.
Does key order matter?
No — objects compare by key, so reordered keys are not reported as changes.
My JSON is invalid — what now?
Each pane shows the parse error and its position; fix it and the diff recomputes live.