JSON Formatter
Format, validate, minify and browse JSON as a tree — instantly, in your browser.
Free Online JSON Formatter, Validator and Beautifier
JSON is easy for machines to read and painful for humans the moment it arrives as one long unbroken line. This free online JSON formatter takes minified, escaped or badly indented JSON and turns it into clean, readable, properly indented output in a single click - no signup, no upload, and no server-side size limit.
The same tool works in both directions. Use Format when you need to pretty print JSON for reading, reviewing or documenting an API response, and Minify when you need to strip every space and newline before shipping a config file, a payload or a database value. Because the parser runs inside your browser, the result appears the moment you stop typing.
What a JSON formatter actually does
A JSON beautifier parses the text you paste, builds the object tree in memory, and then serialises it back out with consistent indentation, the original key order preserved and correct escaping applied. That round trip is also the validation step: invalid JSON cannot be parsed, so the tool reports the error instead of quietly producing broken output. Every format is therefore also a JSON lint check.
How to format JSON online
- Paste your JSON into the input pane, or type it directly.
- Choose an indent style - 2 spaces, 4 spaces or a tab. Two spaces is the default in most JavaScript and TypeScript projects; four spaces is more common in Python and Java codebases.
- Click Format to beautify the document, or Minify to compress the same data down to a single line.
- Read the result in the output pane and click Copy to put it on your clipboard.
- Switch the output to Tree to explore the JSON as a collapsible tree - values are colour-coded by type, and each object or array can be folded away or expanded with Expand all and Collapse all.
Format or minify - which one do you need?
| What you are doing | Best option |
|---|---|
| Reading an API response or a log entry | Format |
| Committing a config file to Git so diffs stay readable | Format |
| Cutting payload size before sending data over the network | Minify |
| Storing JSON in an environment variable or a single database column | Minify |
JSON errors this validator catches
- Trailing commas after the last item of an object or array - legal in JavaScript, illegal in JSON.
- Single quotes around keys or string values; JSON accepts double quotes only.
- Unquoted keys copied straight out of a JavaScript object literal.
- Unescaped line breaks, tabs or backslashes inside string values.
- Comments - JSON has no comment syntax, so
//and/* */break the parse. - Truncated payloads with a missing closing brace or bracket.
Who uses an online JSON beautifier
- Backend and frontend developers inspecting REST or GraphQL responses while debugging.
- QA engineers comparing expected and actual payloads inside a test report.
- DevOps engineers editing
package.json,tsconfig.json,composer.jsonor Kubernetes manifests. - Data analysts reading exports from an analytics platform or a webhook log.
- Technical writers pasting example responses into API documentation.
Is it safe to paste JSON here?
Yes. Nothing you type leaves the page. The formatter is plain JavaScript running in your own browser tab, so access tokens, customer records and internal API responses are never uploaded, logged or stored on a server. That matters when the payload you are debugging contains personal data or credentials, and it means the tool keeps working even after you lose your connection.
Tips for large or awkward JSON
- If the input came from a log file, remove any timestamp or log-level prefix first - the parser needs the text to start at
{or[. - NDJSON (one object per line) is not a single JSON document; format one line at a time.
- A response beginning with
)]}'carries an anti-hijacking prefix that must be stripped before parsing. - Very large documents can be slow to render - minify first, then format only the section you actually care about.
- Numbers larger than 2^53 lose precision in JavaScript; keep them as strings if exactness matters.
Format JSON in VS Code, Notepad++ or from the command line
| Where | How |
|---|---|
| VS Code | Open the file and press Shift+Alt+F (Format Document); the indent follows Editor: Tab Size |
| Notepad++ | Install the JSTool plugin from Plugins Admin, then Plugins, JSTool, JSFormat |
| Command line | python -m json.tool input.json, or jq . input.json if jq is installed |
| JavaScript | JSON.stringify(obj, null, 2) to pretty print, JSON.stringify(obj) to minify |
| Python | json.dumps(obj, indent=2, ensure_ascii=False) |
| PHP | json_encode($data, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE) |
The online formatter wins when the JSON is already on your clipboard, when you are on a machine without your editor set up, or when you want the tree view to find one key inside a large response.
Related tools
Working with API payloads usually means touching more than one format. Decode bearer tokens with the JWT decoder, convert escaped values with the URL encoder and decoder, handle embedded binary with the Base64 encoder, and verify payload integrity with the hash generator. To generate TypeScript, Go or Python types from a JSON sample, use JSON to Types; the guide on typing API responses in TypeScript shows the whole workflow.