Free JSON Formatter & Validator
Make JSON easier to read, check whether it is valid, or minify it for compact output. Paste your data, choose an output style and process it locally in your browser.
Syntax validation only — this does not check API rules or JSON Schema. Processing stays in your browser.
Private: your files are processed in your browser and are never uploaded to our server.
How to use
- Paste or type JSON in the input box.
- Choose Pretty, Minified or Validate only.
- Select Format / Validate to check the input and view the result or a useful error location.
- Copy the result or download it as a .json file.
Format and validate JSON locally
JSON (JavaScript Object Notation) is a text format commonly used for configuration files and data exchange. This tool uses your browser’s built-in JSON parser to validate and format the text.
Your input is processed in this browser tab and is not sent to SindhTools. The tool does not fetch remote schemas or validate your data against an application-specific schema.
Formatting changes whitespace, not the meaning of valid JSON. Minifying removes unnecessary whitespace. Keep sensitive data out of shared computers and clear the input when finished.
Frequently asked questions
What does this JSON tool do?
It checks JSON syntax, formats valid JSON with indentation, minifies it, and lets you copy or download the result.
Is my JSON uploaded?
No. Parsing and formatting happen locally in your browser; the tool does not upload the text.
Does it validate against a JSON Schema?
No. It checks JSON syntax only, not whether the data matches a particular API or JSON Schema.
Why does my JSON fail validation?
Common causes include trailing commas, single-quoted strings, missing quotes around property names, and comments. Standard JSON requires double quotes and does not allow comments.
Can I minify JSON?
Yes. Choose Minified to remove extra whitespace while preserving the data structure.
Can I download the output?
Yes. Use Download JSON to save the result as a .json file.