JSON Diff / Compare
About JSON Diff / Compare
Our free online JSON Diff / Compare tool compares two JSON documents side by side and reports exactly which keys were added, removed, or changed in value - including deeply nested keys, shown with their full path.
This complements the site's JSON Formatter tool (which formats, minifies, and validates a single JSON document) by focusing specifically on comparing two versions of a document. Everything runs locally in your browser; neither document is ever uploaded.
How to Use the JSON Diff / Compare Tool
- Paste your original JSON document into the left panel.
- Paste the updated or second version into the right panel.
- Run the comparison to see a structured list of every key that was added, removed, or changed, with its full nested path shown for context.
- Scan the changed-values list to confirm each modification was intentional before deploying or merging.
- Re-run the comparison after edits to confirm the diff is now clean.
Backend developers use this tool to review what actually changed in an API response between two versions during debugging, especially when a client reports unexpected behavior after a deploy. QA engineers use it to compare an expected fixture against actual output during test failures, and DevOps engineers reach for it when comparing configuration files or environment exports across staging and production. Because the comparison runs locally in your browser rather than on a server, it's safe to use with JSON that contains internal configuration, tokens, or other sensitive data you don't want leaving your machine.
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Frequently asked questions
What counts as a "change" between two JSON documents?
A key present in both but with a different value is 'changed'; a key only in JSON B is 'added'; a key only in JSON A is 'removed'. Nested objects are compared recursively, so a change deep inside a nested structure is reported with its full path (e.g. user.address.city).
Does key order matter?
No - this compares JSON by structure and value, not by the order keys appear in the source text, matching how JSON objects are actually defined (unordered key-value maps).
Is my JSON sent to a server?
No - the comparison runs entirely in your browser; neither document is ever uploaded.
