JSON Formatter
Format, beautify and validate JSON online with clean indentation.
Auto-fix broken JSON: When on, invalid JSON is repaired automatically before running: “Remove” drops the broken property, “Set null” keeps its key with a null value.
Output will appear here...About JSON Formatter
A JSON formatter (also called a JSON beautifier or pretty-printer) takes minified, escaped, or messy JSON and re-indents it into clean, readable structure — turning a single unreadable line into a document you can actually scan. This JSON formatter runs online, entirely in your browser: paste your JSON and the formatted output appears instantly, with your choice of 2-space or 4-space indentation. Every keystroke is validated, so syntax errors are caught with the exact position of the problem, and the optional auto-repair can fix common mistakes like trailing commas and single quotes for you.
It's the everyday tool for developers debugging REST API responses, config files, and log payloads. Because formatting runs locally with no upload, even private API responses and payloads containing sensitive data never leave your machine — there's no server on the other end to see them. Pair it with the JSON Minifier to compress the result back down for production, the JSON Validator to lint before shipping, or the JSON Viewer when a document is so deeply nested that a collapsible tree beats indented text.
How to Use
- 1Paste your JSON — minified, escaped, or messy — into the input area.
- 2Pick 2-space or 4-space indentation; the formatted output updates instantly as you type.
- 3If the JSON is invalid, the error message points at the exact character — fix it by hand or enable Auto-repair to fix common mistakes automatically.
- 4Copy the beautified result to your clipboard or download it as a .json file.
Common Use Cases
- Making a minified API response readable while debugging an integration
- Pretty-printing JSON from logs or a browser network tab to find one field fast
- Cleaning up config files and fixtures before committing them for review
- Formatting JSON before sharing it, so the recipient gets a readable document
Frequently Asked Questions
What indentation options does the JSON formatter support?
You can pretty-print JSON with 2-space or 4-space indentation. If you instead need to compress JSON onto a single line, use the JSON Minifier.
Why does my JSON show as invalid?
The most common causes are trailing commas, single quotes instead of double quotes, unquoted keys, or a missing bracket. The formatter points to the exact character where parsing failed so you can fix it fast — or enable Auto-repair broken JSON to fix them automatically and drop any unparseable property.
Does formatting change my JSON data?
No. Formatting only changes insignificant whitespace — indentation and line breaks between tokens. Every key, value, and the structure itself stays byte-for-byte equivalent, so the formatted document parses to exactly the same data.
What is the difference between a JSON formatter and a JSON validator?
A formatter re-indents the document for readability and validates as a side effect; a validator only checks correctness and reports errors. This formatter does both — it won't format invalid JSON silently, it shows you where parsing failed. For a dedicated lint pass, use the JSON Validator.
Can this JSON formatter handle large files?
Yes. Because everything runs locally in your browser, there's no upload limit — the practical ceiling is your device's memory. Multi-megabyte API dumps format fine; for very large, deeply nested documents the JSON Viewer's collapsible tree is often easier to navigate than flat text.
Is JSON Formatter free to use?
Yes. JSON Formatter is completely free with no sign-up, no subscription, and no usage limits. Every tool on CodeUtilityKit is free forever.
Is my data safe when I use JSON Formatter?
Absolutely. JSON Formatter runs entirely in your browser. Your input is processed locally with JavaScript and is never sent to, stored on, or logged by any server — so it is safe even for private or sensitive data.
Features
- Run JSON Formatter instantly, right in your browser
- 100% private — your data never leaves your device
- Copy the result to your clipboard in one click
- Free and unlimited with no account or sign-up
- Clear, friendly error messages when something is wrong
- Works on desktop and mobile, even offline after first load