Compare JSON
Compare two JSON files online with a semantic diff. Key order, indentation, and formatting are ignored; arrays compare ordered or as sets. Free, with no upload.
Files never leave your browser.
About JSON Diff
Compares two JSON documents structurally, ignoring formatting and key order. Reports added, removed, and changed properties at the path level, so noise from whitespace and key ordering never appears in the result.
How to use
- Paste or load your two JSON documents into the left and right editors. Parse errors are highlighted immediately.
- Under Array comparison pick Ordered, As a set, or By key. By key pairs array items by the value of a key you name, so a moved item shows as a move instead of a delete plus an insert.
- Toggle Sort keys to ignore key-ordering differences inside objects.
Try a sample
Loads two versions of a package.json with version bumps and a new dependency. A common diff pattern.
What this tool doesn't handle
- JSON with comments or trailing commas is not accepted. Paste through a JSON5 formatter first if needed.
- Deep equality is structural only; types like Dates or BigInts are not part of standard JSON and behave as strings.
Frequently asked questions
Do my files ever leave my browser?
No. Every comparison runs locally in your browser. Nothing you paste, drop, or load is uploaded to a server; the tool keeps working even if you go offline after the page loads.
Is this tool free to use?
Yes. All DiffResolver tools are free, with no account, sign-up, or installation. Because processing happens on your device, there are no server-imposed usage limits.
Does the order of keys matter when comparing JSON?
No. Objects are compared structurally, so the same properties in a different order show no difference. For arrays it is configurable: Ordered mode treats reordering as a change, As a set ignores it.
Why is my JSON rejected with a parse error?
The input must be strict JSON: double-quoted keys, no comments, no trailing commas. Config dialects that look like JSON (JSON5, JSONC) need converting before comparison.
Can I diff a minified API response against a pretty-printed one?
Yes, formatting is irrelevant. Both documents are parsed first, so minified and pretty-printed JSON compare as equal whenever the underlying data matches.
Is there a file size limit?
No server limit applies, because nothing is uploaded. The memory of your device sets the practical limit. Above 10 MB for text, 40 MB for images, 100 MB for documents, or 500 MB for archives, the tool warns you that the work can be slow, but it never blocks the file.
Does this tool work offline?
Yes. The browser keeps a copy of the tool after the first visit, so a page you opened before still works without a network. You can also install DiffResolver as an app from the browser menu. Installation stays optional; the site works the same in a normal tab.
Where is my data stored?
Your files are stored nowhere. They stay in the memory of the page and are gone when you close the tab. Only what you save yourself stays in this browser: a snapshot, your tool options, and your theme. To remove it, open Settings and select Clear all local data.