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Compare two JSON objects side by side. Differences are color-coded: green for additions, red for deletions, and yellow for changes. All processing happens client-side.
A structural diff is the fastest way to answer "what actually changed?" between two API responses, two versions of a configuration file, or the payload your code sends versus the one the docs expect. Because the tool parses both documents before comparing, cosmetic differences like key order, indentation, or minified versus pretty-printed formatting never show up as noise — every reported difference is a real change, listed with the exact JSON path where it occurred.
Typical uses: reviewing what a deploy changed in a config, spotting which field an API started returning differently, or verifying that a migration preserved your data. If one of your documents will not parse, run it through the JSON Validator first to find the syntax error.
FAQ
How does the JSON diff work?
The tool performs a deep comparison of both JSON structures, comparing every key and value recursively. It detects additions (keys in modified but not original), removals (keys in original but not modified), and changes (same key, different value).
Does order matter when comparing?
For objects, key order does not matter — only the values are compared. For arrays, order matters — elements are compared by index position.
Is my JSON uploaded to a server?
No. The diff runs entirely in your browser with JavaScript. Neither JSON document is sent to a server, so it is safe to compare API responses or configuration files that contain sensitive data.
Can I diff large JSON files?
Yes. The tool handles documents up to several megabytes — the limit is your browser's memory. For very large structures the comparison may take a moment to complete.
Why diff JSON instead of plain text?
A plain text diff flags every formatting difference — reordered keys, indentation, trailing whitespace — even when the data is identical. A structural JSON diff parses both documents first, so it only reports real changes to keys and values.