Loading tool…
Beautify, minify, sort, repair and validate JSON with precise error location, a collapsible tree view and path queries.
Paste or type your input here, JSON Formatter is loading…
JSON Formatter makes JSON readable, valid, and tidy. Paste a minified or messy blob and it beautifies the structure with consistent indentation; paste clean JSON and it can minify it down to a compact single line. Either way, a live validator checks that the JSON is well-formed.
When something is wrong, the formatter doesn't just say 'invalid', it shows where and why, flagging the line and the specific issue. Since JSON is stricter than JavaScript object notation, that usually means a trailing comma, single quotes, an unquoted key, or a missing bracket, all of which the tool helps you find fast.
Everything happens in your browser, which matters for developers: API responses, tokens, and configuration files often contain sensitive data you don't want to paste into a server-side tool. Here, nothing is uploaded. A collapsible tree view also makes large, deeply nested payloads easy to explore.
It sits alongside the other ToolsMonk developer utilities, JSON to YAML, JSON to TypeScript, and JSON Minifier, so you can format a payload, inspect it, and convert it into the exact shape your code needs, all locally and for free.
| Price | Free, no signup, no paywall, no watermark |
|---|---|
| Works on | Any modern browser: desktop, tablet, and mobile |
| Processing | In your browser, files never leave your device |
| Account required | None |
| Category | Developer Tools |
Paste your JSON into the input area, or load it from a file
Choose your indentation and click Format to beautify, or Minify to compact it
If the JSON is invalid, the tool highlights the error location and message so you can fix it
Copy or download the cleaned-up result
Beautify minified JSON with proper indentation, or minify formatted JSON back to a compact single line
Real-time syntax validation that pinpoints the line and reason for an error
Adjustable indentation (2 spaces, 4 spaces, or tabs) to match your codebase style
Collapsible tree view to navigate large, deeply nested objects
One-click copy and download of the formatted output
100% in-browser, your JSON, including API payloads, never leaves your device
Making a minified API response readable while debugging requests and webhooks
Validating a config or data file to catch the exact syntax error breaking your build
Cleaning up and re-indenting JSON before committing it to a repository
Minifying JSON to reduce payload size before embedding it in code or a request
If validation fails, check the very end of the JSON first, a trailing comma after the last array or object item is the single most common error
Use the tree view to verify structure quickly: a key that should hold an array but shows an object is an easy bug to miss in raw text
Minify JSON before pasting it into source code or a URL parameter, then keep a beautified copy for yourself to read
Common questions about this tool, its workflow, and what to expect before you use it.
IETF
Defines valid JSON, which is what the validator checks your input against.
No ratings yet. Be the first to say how JSON Formatter worked for you.
Reviews appear here once our team has read them, so everything you see is from someone who signed in and used the tool.
Get notified about new tools, features, and tips. No spam, unsubscribe anytime.
One of our pages answered 2,318,515 bytes and 82.7% of that was props serialized into the HTML, not content. Here is how Client Component props get shipped twice, the projection that cut the page by 76%, and the measuring mistake that first told us everything was fine.
Read the guide 8 min readJSON is the universal data format powering APIs, configs, and databases. Everything you need to know about JSON formatting, validation, beautification, and best practices, with free online tools to speed up your workflow.
Read the guide 7 min readJSON Web Tokens power authentication in millions of web applications. Understand how JWTs work, their structure, security considerations, and best practices for implementing stateless authentication in your projects.
Read the guide 8 min readMessy, inconsistent code is harder to read, debug, and maintain. Learn how code beautification tools and consistent formatting standards improve code quality, team collaboration, and long-term maintainability.
Read the guide 6 min readUTF-8-safe Base64 encode & decode with a URL-safe variant, line-wrapping and file-to-Base64 (data URI).
Open toolEncode and decode URLs and components, with a live breakdown of query parameters.
Open toolDecode and inspect a JWT's header, payload and claims with human-readable timestamps and live expiry status.
Open toolGenerate MD5, SHA-1, SHA-256, SHA-384, SHA-512 and HMAC digests for text or files.
Open toolTest and debug regular expressions with live match highlighting, capture groups, replace and example patterns.
Open toolMinify HTML, strip comments and whitespace while protecting pre/script/style, with a size-saved readout.
Open toolMinify CSS, remove comments and whitespace safely (strings and data URIs preserved) with a size-saved readout.
Open toolConvert JSON to YAML and YAML back to JSON, bidirectional, no server round-trip.
Open toolWriting a roundup or tutorial? Embed the live JSON Formatter so readers use it right on your page, or drop in a ready-made card that links to it. Free to use, always.
Preview
Beautify, minify, sort, repair and validate JSON with precise error location, a collapsible tree view and path queries.
Use JSON Formatter free →Live tool (iframe)
Readers use the real, working tool right on your page, with a small credit line underneath.
Embed card (HTML)