JSON Diff — Compare JSON Online
Spot every difference between two JSON objects instantly. Colour-coded additions, removals, and changes — with JSON Patch export for programmatic application.
How to Use the JSON Diff — Compare JSON Online
- 1
Paste the first JSON document into the left panel above.
- 2
Paste the second JSON document into the right panel.
- 3
JSON Flash immediately highlights differences: green for added, red for removed, yellow for changed.
- 4
Click any highlighted difference to jump to the corresponding line in both panels.
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Switch to "JSON Patch" view to export the diff as an RFC 6902 patch document.
Key Features
Deep Structural Diff
Compares every nested key and value — not just top-level properties. Full JSON path shown for each difference.
Colour-Coded Changes
Added keys are green, removed keys are red, changed values are yellow — consistent with Git diff conventions.
JSON Patch Export
Export the diff as an RFC 6902 JSON Patch document — apply it programmatically with any JSON Patch library.
Flexible Comparison
Toggle key-order and array-order sensitivity independently to match the semantics of your data.
Why JSON Flash?
- Ignores JSON object key order by default — spec-correct comparison.
- Three view modes: side-by-side, unified, and JSON Patch list.
- RFC 6902 JSON Patch export for programmatic diff application.
- Runs entirely in your browser — both JSON documents stay private.
- Free for files up to 5 MB per side.
Frequently Asked Questions
What is a JSON diff tool?
A JSON diff tool compares two JSON documents and highlights the differences — added keys, removed keys, and changed values — making it easy to spot exactly what changed between two API responses, config versions, or database records.
How does JSON Flash compare JSON?
JSON Flash performs a deep structural comparison. It identifies added properties (green), removed properties (red), and changed values (yellow) at every level of nesting, with the full JSON path to each difference.
Does the diff ignore key order?
Yes. JSON objects are unordered by specification, so JSON Flash ignores property order when comparing. {"a":1,"b":2} and {"b":2,"a":1} are considered identical.
Does the diff ignore array order?
By default, array order matters — [1,2] and [2,1] are different. Enable "Ignore array order" to compare arrays as sets, useful for comparing API responses where item order is non-deterministic.
Can I see the diff as a JSON Patch?
Yes. JSON Flash can export the diff as a JSON Patch document (RFC 6902) — an array of add, remove, replace, move, copy, and test operations. This is machine-readable and can be applied to the original document programmatically.
What view modes are available?
JSON Flash offers three views: Side-by-side (left vs. right panels with inline highlighting), Unified diff (Git-style), and JSON Patch list (machine-readable RFC 6902 patch operations).
Can I diff large JSON files?
Free users can diff files up to 5 MB each. Pro users can diff files up to 50 MB per side using a streaming diff engine that avoids blocking the browser UI.
Can I share a diff with a colleague?
Pro users can generate a shareable diff link that encodes both JSON documents and the diff result. The link expires after 24 hours for security.
Related Tools
Unlock Pro — unlimited AI, 10 MB files, API access
Starting at $4/mo · 14-day money-back guarantee
- ✦Diff files up to 50 MB per side with streaming mode
- ✦Shareable diff links (24 h expiry)
- ✦Ignore specific keys during comparison
- ✦Apply JSON Patch operations directly in the editor
- ✦API endpoint for automated diff pipelines