Compact API response
Input: {"name":"AiFolder","free":true}
Result: The same object with readable indentation and line breaks.
JSON Prettify
Format, validate, or minify JSON directly in your browser, choose indentation, upload a .json file, inspect parser errors, copy the result, and download formatted JSON.
About this tool
What is JSON Formatter & Validator?
Format, validate, or minify JSON directly in your browser, choose indentation, upload a .json file, inspect parser errors, copy the result, and download formatted JSON.
Motion showcase
See JSON Formatter & Validator in action
A short visual walkthrough generated from this tool's current workflow.
What you can do
- Prettify valid JSON with 2–8 spaces of indentation
- Minify JSON for compact transport or fixtures
- Validate JSON syntax and surface the parser error instead of silently repairing input
- Show line and column information when the browser parser exposes a character position
- Read a local .json file, copy output, and download the formatted or minified result
How to use JSON Formatter & Validator
- 1Paste JSON or choose a local .json file.
- 2Use Validate to check syntax, or choose Prettify or Minify for the output you need.
- 3If parsing fails, start with the reported parser error and line/column when available.
- 4Review the output, then copy or download it.
- 5Use Save run only when you intentionally want the current input and output stored by AiFolder.
Examples
Invalid trailing comma
Input: {"name":"AiFolder",}
Result: An invalid JSON message; the formatter does not guess how malformed input should be repaired.
Tool facts
- Input
- JSON text or a local .json file
- Output
- Formatted or minified JSON text
- Indentation
- 2–8 spaces
- Syntax validation
- Browser JSON parser
- Account required
- No account is required for formatting, validation, copy, or download
Limitations
- Syntax validation does not prove that the JSON matches an API schema, required fields, or business rules.
- The formatter does not automatically repair malformed JSON because an automatic repair can change the intended data.
- Parser wording varies by browser, so exact error messages and available location details can differ.
Privacy and data handling
Formatting, validation, minification, local file reading, copy, and download run in the browser. The separate Save run action can send the current input and output to AiFolder storage; do not use Save run for secrets or data you do not want stored.
FAQ
JSON Formatter & Validator FAQs
?Why are comments or trailing commas rejected?
The formatter parses JSON, not a JavaScript object literal. Remove comments, trailing commas, and unquoted property names before retrying.
?Should I choose prettify or minify?
Prettify adds indentation for inspection. Minify removes unnecessary whitespace. Neither option is intended to change the parsed values.
?Can large integer IDs change during formatting?
JavaScript number parsing can lose precision for integers beyond its safe range. Keep long identifiers as quoted strings and compare the output before reuse.
JSON workflow
Continue with JSON debugging and conversion
How to format JSON without uploading your data
A practical browser-formatting workflow and privacy checklist.
Common JSON errors and how to fix them
Trailing commas, quotes, escapes, invalid numbers, and parser failures.
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