Semantic JSON comparison
Whitespace, indentation, and object-property order do not create noise in the default comparison. A string, number, boolean, null, empty array, and missing property are all treated as meaningfully different states.
Private browser-based JSON diff
JSON Compare Online
Compare two JSON files side by side and instantly find added, removed, changed, and moved values. Your data is processed locally and never uploaded.
Your JSON stays in this browser. Files are read directly from your device.
Comparison settings
Object rules
Array rules
Match by key works with arrays of objects. The tool warns before it falls back to positions.
Advanced
Original JSON
Original JSON
Paste JSON or drop a .json file here.
Modified JSON
Modified JSON
Paste JSON or drop a .json file here.
Comparison results
Differences you can act on
Ready to compare.
0Additions
0Removals
0Changed values
0Type changes
0Moved items
Compare JSON without guessing what changed
JSON Compare is built for the practical work behind an API response, configuration update, or data migration. It compares the structure and values, not just the way the text happens to be formatted.
Array rules that match the job
Use position for ordered results, ignore order for tag-like collections, or match object records by an identity property such as id or uuid. Duplicate and missing identity values are called out.
Local by design
The comparison worker runs in the browser. There is no account, automatic cloud save, or document upload step. Clear the editors when you are done to remove the in-page copy.
Where JSON comparison helps most
API testing
Check expected and actual responses, then focus on the exact property that changed instead of scanning two large payloads line by line.
Environment config
Compare development, staging, and production settings while keeping formatting differences out of the way.
Migration review
Review transformed data, find missing fields, and export a clean change summary for a ticket, pull request, or handoff.
Version checks
Match arrays of records by a stable key when order is not important but the identity and values of each record are.
JSON Compare FAQ
Does JSON Compare upload my files?
No. JSON Compare reads, parses, compares, merges, and exports data in your browser. Choosing a file only lets your browser read that local file; it is not sent to Compare2Lists for processing.
Why can two JSON files look different but have no differences?
Semantic comparison ignores formatting, line endings, and object-property order by default. If the underlying values are the same, there is nothing to fix.
What is the difference between array modes?
By position compares each index. Ignore order treats arrays as collections while keeping duplicate counts. Match by key is designed for arrays of objects, such as API records with an id or uuid.
Can I export a JSON Patch?
Yes. After a comparison, export an RFC 6902 JSON Patch, a Markdown summary, a JSON change list, or CSV. Keys containing slashes and tildes are escaped in patch paths.
Can I merge one change without overwriting everything?
Yes. Each listed difference has directional merge controls. The tool updates only the document you choose and keeps an undo history for merge actions during the current session.
What happens if my JSON is invalid?
The editor points out the parse problem before comparison. Empty editors are treated as empty, not as an error, and comparison remains disabled until both documents are valid JSON.
Related comparison tools
Compare URLs
Inspect URL paths, parameters, and fragments without making a network request.
Open toolCompare Two Texts
Compare pasted paragraphs, writing revisions, and snippets when a text diff is the right fit.
Open toolCompare Two Lists
Compare pasted list values and find unique entries, shared items, and duplicates.
Open toolCompare Two Files
Review ordinary text and code files line by line when semantic JSON comparison is not the right fit.
Open toolYAML Compare
Compare YAML mappings, sequences, scalar types, and multi-document streams locally.
Open toolXML Compare
Compare XML semantically when namespaces, attributes, and element structure matter.
Open toolBrowse all comparison tools
See the full collection of browser-based comparison and list tools.
Open tool