JSON Formatter
Beautify, pretty print, and format JSON with customizable indentation. Validate syntax and copy clean JSON for your projects.
JSON formatter — beautify and validate JSON online
A JSON formatter helps developers read, debug, and work with JSON data more efficiently. FormatList's free online JSON formatter takes messy, minified, or poorly formatted JSON and turns it into clean, indented, human-readable JSON in milliseconds.
Whether you're inspecting an API response, debugging a webhook payload, or preparing data for documentation, this tool handles formatting, validation, and syntax checking — all in your browser with nothing uploaded to any server.
Why use a JSON formatter?
- Beautify minified JSON for better readability.
- Validate JSON syntax with real-time error detection.
- Choose indentation: 2 spaces, 4 spaces, or tabs.
- Minify formatted JSON back to a compact string.
- 100% client-side — your data never leaves your browser.
Common use cases
- API development — format API request/response payloads.
- Debugging — read minified JSON from logs and error reports.
- AI prompts — prepare clean JSON for LLM context and tool calls.
- Data export — beautify JSON exports for documentation.
- Configuration files — format JSON config files for readability.
How to use the JSON formatter
- Paste your JSON into the input panel on the left.
- It formats automatically with default 2-space indentation.
- Switch between 2/4 spaces or tab indentation as needed.
- Click Copy to copy the formatted result to your clipboard.
JSON formatter FAQ
What is a JSON formatter?
A JSON formatter takes raw or minified JSON and adds proper indentation, line breaks, and spacing to make it human-readable. It also validates that the JSON syntax is correct.
How do I format JSON online?
Simply paste your JSON into the input panel. It formats automatically as you type with configurable indentation (2 spaces, 4 spaces, or tabs).
Can I minify JSON back?
Yes. Click the Minify button to convert formatted JSON back to a compact, single-line string — useful for API payloads or storage.
Will it validate my JSON?
Yes. If the JSON has syntax errors (missing commas, trailing commas, unescaped quotes), the tool shows an error message explaining what's wrong.
Is my data sent to a server?
No. All formatting and validation happens locally in your browser using JavaScript's built-in JSON parser. Your data never leaves your computer.
Is this tool free?
Yes. Free to use with no signup and no usage limits. Format as much JSON as you need.
Related JSON tools
Format, validate, repair, compare, escape, and transform JSON with these browser-based tools.