JSON Formatter makes JSON (JavaScript Object Notation) readable. Paste a compact API response, configuration file or log entry, and it is re-indented into a clean, nested structure. The validator tells you whether the JSON is correct, and if it isn't, it shows the line and column of the error.
You can also minify JSON to strip all whitespace before shipping it, and sort object keys alphabetically to make two JSON documents easier to compare. Everything runs locally, so API keys and private data in your JSON never leave your browser.
How to use the JSON Formatter tool
- Paste your JSON into the box.
- Click Format / Beautify to indent it, or Minify to compact it.
- If it's invalid, read the error message. The problem character is highlighted.
- Copy the result.
Features
- Beautify with 2 spaces, 4 spaces or tabs.
- Minify for the smallest payload.
- Validation with line and column numbers.
- Optional alphabetical key sorting.
- 100% client-side, so it's safe for sensitive data.
Tips for best results
Common JSON errors are trailing commas after the last item, single quotes instead of double quotes, unquoted keys, and comments, none of which are allowed in strict JSON. When comparing two API responses, enable Sort keys on both, then paste them into Text Compare to see the real differences.
Compatibility and limits
The JSON Formatter tool is built for developers, testers, students and anyone who handles data. It runs in every modern browser, needs no installation or extension, and keeps working offline once the page has loaded. Because nothing is sent to a server, it's safe to use with production data, access tokens and internal configuration files.
Privacy: your files never leave your device
The data you enter is processed entirely in your browser with JavaScript. Nothing is sent to a server, which makes the tool safe for API responses, tokens, configuration files and other sensitive developer data.
Frequently asked questions
What does a JSON formatter do?
It adds indentation and line breaks so nested JSON data is easy for people to read, without changing the data itself.
How do I find an error in my JSON?
Click Validate. The message shows the error with its line and column, and the problem position is selected in the editor.
Is my JSON sent to a server?
No. Parsing and formatting happen in your browser.
Does sorting keys change my data?
Only the order of keys in objects changes. Values and array order stay the same.
Can it handle large files?
Yes. Several megabytes of JSON are formatted almost instantly on most devices.