Free browser-based data tool

JSON Diff & Compare

Compare two JSON documents instantly. Everything stays in your browser.

Your files never leave your computer.All processing happens locally inside your browser.

Validate two pasted or uploaded JSON documents
Find additions, removals, and changed values by path
Download a complete JSON or text comparison report

Upload JSON A

Choose the original or baseline JSON document.

Drop JSON A here

or use the file browser

Upload JSON B

Choose the updated or comparison JSON document.

Drop JSON B here

or use the file browser

Paste and validate both documents

The editors preserve the original documents while validation updates.

JSON A

JSON A is waiting for input.

JSON B

JSON B is waiting for input.

What JSON comparison is

Find structural and value differences by path

JSON comparison recursively checks two parsed documents. Shared properties are compared by name, arrays are compared by index, and every difference receives a readable path with its before and after values.

Developer use cases

Review data changes without editing either source

Compare API responses before and after a release
Review generated fixtures against expected output
Inspect feature-flag or application configuration changes
Check exported records from two environments
Find a changed nested value without scanning manually
Create a portable comparison report for a code review

API testing

Separate meaningful response changes from key order

Paste two response bodies to compare their parsed structure. Property order does not create false differences. Type changes, missing properties, new properties, and changed array positions remain visible with their exact JSON paths.

Configuration comparison

Audit environment settings before deployment

Compare local, staging, or production configuration exports without sending secrets to a server. The tool is read-only: it preserves both originals and does not merge, patch, or rewrite either document.

Examples

Readable paths identify every difference

JSON A	JSON B	Result
`{"version":1}`	`{"version":2}`	`changed $.version`
`{"name":"A"}`	`{"name":"A","active":true}`	`added $.active`
`{"old":true}`	`{}`	`removed $.old`

Data Toolkit

Use every UtilityDock JSON workflow

JSON Formatter & ValidatorPretty print and validate JSON.JSON MinifierRemove unnecessary JSON whitespace.JSON Key SorterNormalize object-key order recursively.JSON to CSVConvert JSON objects into CSV rows.CSV to JSONTurn CSV rows into JSON objects.JSON Lines ConverterConvert JSON arrays and JSONL records.

FAQ

Questions about comparing JSON

Does UtilityDock upload or store either JSON document?

No. Your files never leave your computer. Validation, comparison, display, and report creation all happen locally inside your browser.

Does JSON property order affect the comparison?

No. Object keys are compared by name, so a different property order alone is not reported as a difference.

How are arrays compared?

Version 1 compares arrays by index. Added or removed positions are structural differences, and reordered items may appear as changed values.

What counts as a changed value?

A shared path is changed when its JSON value or type differs, such as 1 versus 2, true versus false, or a string versus an object.

Can this tool merge JSON or create a patch?

No. Version 1 is read-only comparison. It does not merge documents, generate patches, compare schemas, or keep history.