What is JSON Formatter?

JSON Formatter is a tool for converting unformatted JSON into readable format with indentation and line breaks. Also called JSON Beautifier, JSON Prettifier, or Pretty Print JSON.

Minified JSON saves space but is unreadable for humans. Formatting adds indentation and line breaks, making the data structure clear. Essential for debugging APIs, analyzing configs, and working with data.

Does the tool validate JSON?

Yes. JSON is fully parsed during formatting. If there are syntax errors (missing comma, quote, bracket), you'll get an error message describing the problem.

Which indent to choose: 2 or 4 spaces?

2 spaces is standard for JavaScript/TypeScript and most web projects. 4 spaces is traditional in Java, C#, Python communities. Tabs are less common. Choose what's standard in your project.

Is key order preserved?

Yes. The tool preserves original object key order. In JSON, key order is technically not guaranteed, but practically all modern parsers preserve it.

Does it work with large files?

Yes, up to 10 MB. For very large JSON (hundreds of megabytes), use command line: jq or python -m json.tool. Web tools are limited by browser memory.

Is it safe to paste confidential data?

Yes. Formatting is done entirely in your browser. Data is not sent to the server. You can verify in DevTools: Network tab won't show any requests with your data.

Is JSON with comments (JSONC) supported?

Standard JSON doesn't support comments. If your file contains comments (// or /**/), it's JSONC — an extension used by VS Code. Remove comments before formatting.

How to format JSON in command line?

Use jq: cat file.json | jq or python: python -m json.tool file.json. In Node.js: node -e "console.log(JSON.stringify(require('./file.json'), null, 2))"

Can I format JSON5 or Hjson?

No. The tool only supports standard JSON (RFC 8259). JSON5 and Hjson are extensions with non-standard syntax requiring separate parsers.

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JSON Formatter

JSON Formatter

Transform minified or unformatted JSON into readable format with proper indentation. Instant syntax validation and formatting right in your browser.

Options

Indent

Number of spaces for indentation

All About JSON Formatting

When you need JSON Formatter

When debugging API responses, analyzing logs, working with config files. Minified JSON saves bandwidth but is completely unreadable. Formatting is the first step to understanding data structure.

JSON in web development

JSON is the standard for data exchange on the web. REST APIs, webpack/vite/eslint configs, package.json, PWA manifests, localStorage data — JSON everywhere. Reading and formatting it is a basic developer skill.

Common JSON errors

Trailing comma (comma after last element), single quotes instead of double, unquoted keys, comments, NaN/Infinity instead of null. All these violate JSON standard and cause parsing errors.

JSON vs JavaScript objects

JSON is stricter: only double quotes, all keys quoted, no trailing comma, no comments, only primitives (strings, numbers, boolean, null, arrays, objects). JavaScript objects are more flexible but not interchangeable.

Tools for working with JSON

VS Code with Prettier extension, jq for command line, JSON Viewer for browser, Postman/Insomnia for APIs. Online formatters are convenient for quick tasks without installation.

How to format JSON

Paste JSON

Enter JSON in the text field or upload a .json file. Files up to 10 MB are supported.

Choose indent

Select indent size: 2 spaces (web standard), 4 spaces (Java/C#), or tabs.

Copy result

Click "Format" and copy the formatted JSON. Syntax errors will show a hint with error position.