JSON Compare Online
Compare two JSON objects side-by-side and highlight the differences. Supports tree view and raw diff.
Related Tools
Learn more about the JSON Compare
What Does This JSON Comparison Tool Do?
This tool compares two JSON documents and highlights exactly what differs between them — added keys, removed keys, and changed values — including differences nested deep inside objects and arrays, not just at the top level.
Paste the original and modified JSON into the two editors — or drag and drop two .json files, or paste from your clipboard — then click Compare to see a side-by-side diff with additions and removals color-coded. Both inputs are validated first, so a syntax error is caught before it's mistaken for a real difference.
Everything runs locally in your browser; your JSON and files are never sent to a server. It works equally well as a quick JSON diff checker for two small objects and as a JSON comparator for full API responses or config files.
How to Compare JSON
- Add the original JSON. Paste or type the first JSON object into the left editor, or drag and drop a .json file onto it.
- Add the JSON to compare against it. Paste or upload the second JSON document into the right editor — an updated API response, a newer config, or a later export.
- Click Compare. Both inputs are validated first, so a syntax error is caught before it can be mistaken for a real difference.
- Review the diff. Added keys and values are highlighted in green, removed ones in red — including differences nested inside objects and arrays.
JSON Diff
A JSON diff is the set of differences between two JSON documents — the keys that were added or removed, and the values that changed — reported per field rather than line by line. That makes a dedicated JSON diff more useful than a plain text diff for JSON: reordering keys or reformatting whitespace doesn't register as a change, only the actual data does.
This runs as a JSON diff online, entirely client-side, so it works the same whether you're diffing two small objects or two large exported files.
Compare JSON Objects
To compare JSON objects, paste each one into an editor — no file required. This is the fastest path for short snippets: API payloads, config blocks, or objects copied from a debugger. The tool deeply compares nested objects and arrays, so a changed value three levels deep is flagged just as clearly as a top-level one.
Compare JSON Files
To compare JSON files, drag and drop two .json files onto the editors, or click the upload icon in the panel header to browse for them. Files are read directly in your browser and never uploaded to a server, so comparing exported data, snapshots, or config files stays private.
Common Use Cases
API Testing
Compare an expected API response against the actual response to confirm your endpoint returns exactly what it should.
Config Management
Diff configuration files across environments (staging vs. production) to catch unintended drift before it causes an incident.
Debugging
When behavior changes after a data update, comparing the before and after JSON pinpoints exactly which field changed.
Version Tracking
See what changed between two versions of a JSON file — useful for reviewing data exports, snapshots, or generated files.
JSON Comparison Example
Here are two versions of the same JSON object — comparing them flags the changed age and city values, plus the added "TypeScript" skill.
{
"name": "Alice",
"age": 30,
"city": "New York",
"skills": ["JavaScript", "React"]
}{
"name": "Alice",
"age": 31,
"city": "San Francisco",
"skills": ["JavaScript", "React", "TypeScript"]
}JSON Compare vs JSON Formatter
JSON Compare and JSON Formatter solve different problems. JSON Compare diffs two documents against each other and shows what changed. JSON Formatter works on a single document — to beautify, minify, or view it as a tree. If your JSON is unformatted or you're not sure it's valid, run it through JSON Formatter or the JSON Validator first, then come back here to diff it against another version.
Features
Compare
Diff two JSON documents and highlight added, removed, and changed values.
Deep Comparison
Nested objects and arrays are compared at every level, not just the top level.
Upload JSON Files
Drag and drop or upload two .json files to compare them directly, no copy-pasting required.
Paste from Clipboard
Paste JSON directly into either editor with a single click.
Sample Data
Load two sample JSON objects to see how the diff view works.
Looking for other JSON tools? Browse the full JSON tools category, or try JSON Escape/Unescape, JSON Schema Generator, and Text Compare for diffing plain text instead of structured JSON.
How to use
Paste your input in the left editor. The output appears automatically on the right. Use the toolbar buttons to copy, download, or transform the result.
- Paste or type your content in the input editor on the left.
- The formatted output is generated automatically.
- Use Copy, Download, or other actions from the output toolbar.
- Click the expand icon to view the output in fullscreen.
FAQ
Is this JSON compare tool free?
Yes, the JSON compare tool is completely free to use with no limits, signup, or account required.
Is my JSON data uploaded to a server?
No. All comparison happens entirely in your browser, whether you paste JSON or upload files. Your data never leaves your machine.
How does JSON Compare work?
Paste two JSON objects into the left and right editors, then click Compare. Differences are highlighted with added values in green and removed values in red.
Can I compare two JSON files instead of pasting JSON?
Yes. Drag and drop a .json file onto either editor, or click the upload icon in the panel header to browse for one. Files up to 5MB are supported.
Does it support nested JSON?
Yes, JSON Compare deeply compares nested objects and arrays, highlighting differences at every level.
Can I compare large JSON files?
Yes, the comparison runs client-side in the Monaco editor, the same editor used in VS Code, so it handles large documents smoothly.
Does it show differences inside arrays?
Yes, added, removed, or reordered array items are highlighted just like changes inside objects.
Does the tool validate JSON before comparing?
Yes, if either input has a syntax error it is flagged before the comparison runs, so you always compare valid JSON.
Can I use this to compare API responses?
Yes, it’s commonly used to diff an expected API response against an actual one, or to compare config files across environments.
What is the difference between JSON Compare and JSON Formatter?
JSON Compare diffs two JSON documents against each other and highlights what changed between them. JSON Formatter works on a single JSON document to beautify, minify, or validate it. Use JSON Formatter to clean up messy JSON first, then JSON Compare to see how two documents differ.