Developer JSON Tool
Free JSON Formatter & Validator
Beautify, minify and validate JSON directly in your browser. Find syntax errors, copy clean output and download a ready-to-use JSON file without uploading your data.
Format, Minify and Validate JSON Online
Paste JSON into the editor, then format, minify or validate it. Processing happens locally in your browser.
JSON Input
0 characters
Processed Output
0 characters
How To Use
Work with JSON in Three Steps
Format, validate or compress JSON without sending the content to an external service.
Paste your JSON
Add an object, array or other valid JSON value to the input editor.
Choose an action
Beautify the structure, minify it or validate the syntax without changing the data.
Copy or download
Use the clean output in an API request, application or configuration file.
JSON Guidelines
Avoid Common Syntax Errors
These simple checks resolve many invalid JSON problems.
Use double quotes
Property names and string values must use double quotation marks in valid JSON.
Avoid trailing commas
Do not add a comma after the final property or array item.
Match brackets and braces
Every opening brace or bracket must have a matching closing character.
Common Questions
JSON Formatter & Validator FAQs
Quick answers about validation, formatting and browser-based processing.
What does formatting JSON change?
Formatting changes indentation and line breaks for readability. It does not intentionally change the underlying data values.
What does minifying JSON do?
Minifying removes unnecessary spaces and line breaks to produce a smaller JSON string.
Why is my JSON invalid?
Common causes include trailing commas, single quotes, unescaped characters, missing quotation marks and mismatched braces or brackets.
Is my JSON uploaded to a server?
No. The formatter and validator operate locally in your browser using JavaScript.
Can the tool format arrays as well as objects?
Yes. Any valid JSON value supported by JSON.parse can be formatted, including arrays, objects, strings, numbers, booleans and null.
Related Tools
Continue Your Developer Workflow
Use related tools to inspect text, URLs and structured data.
Format and Validate Your JSON Before Using It
Clean the structure, catch syntax errors and download a ready-to-use JSON file.