Toolest

JSON Formatter

Format and validate JSON for debugging, APIs and config files.

Updates instantly as you type

01 / Fast steps

  1. Paste your raw or minified JSON.
  2. The formatted, validated output appears as you type.
  3. Copy the pretty JSON or download it as a file.

02 / Best for

  • Make minified API responses readable while debugging.
  • Validate config files before committing them.
  • Clean up JSON copied from logs, network tabs or documentation.

03 / Why here

  • Formats and validates in one step, live as you type.
  • Runs entirely in your browser, so API payloads and credentials never leave your device.

04 / Keep in mind

  • Invalid JSON is rejected with an error rather than auto-repaired.
  • Extremely large documents may be slow to format in the browser.

Tool connections

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Good to know

Questions & answers

01

Is my JSON uploaded anywhere?

No. Parsing and formatting happen locally in your browser, so API responses, tokens and internal data never leave your device.

02

Why is my JSON reported as invalid?

Common causes are trailing commas, single quotes instead of double quotes, unquoted keys and comments, none of which are allowed in strict JSON.

03

Can it minify JSON too?

This page focuses on pretty-printing and validation. For structure comparison use the JSON Diff Checker, or convert to other formats with JSON to CSV and JSON to XML.

04

Is JSON Formatter free to use?

Yes, JSON Formatter is completely free, with no sign-up and no usage limits. It runs entirely in your browser, so your data never leaves your device.