JSON Formatter / Validator
Last updated: 2026-06-25
The JSON formatter is a free tool that beautifies a JSON string with readable indentation, minifies it to a single line, and validates it to tell you where syntax errors are.
Everything runs in your browser and the JSON you enter is never sent to or stored on a server.
JSON input
Result
How to use
- Enter JSON — paste the JSON string you want to format or validate into the input box.
- Choose an action — click Beautify (indent), Minify, or Validate. You can also pick the indentation width.
- Review and copy — the result area shows the formatted JSON or the error position (line, column), and the copy button copies the result.
What beautify, minify and validate do
JSON (JavaScript Object Notation) is a lightweight format that represents data as key-value pairs. When working with API responses or config files, JSON minified to one line is hard to read, while indented JSON is readable but larger. This tool converts the same data into whichever form you need and checks whether the syntax is valid.
| Action | Result | Main use |
|---|---|---|
| Beautify | Adds indentation and line breaks | Code review, debugging, readability |
| Minify | Removes whitespace and line breaks, one line | Smaller transfer size, storage |
| Validate | Shows syntax errors and their position | Debugging errors, input validation |
Both beautify and minify read the structure with JSON.parse() and re-serialize it with JSON.stringify(). Key order and values are preserved, and invalid JSON is not converted — an error message is shown instead. If you need encoding, use the Base64 encoder/decoder; for hashing, use the SHA hash generator.
Frequently asked questions (FAQ)
Is the JSON I enter sent to a server?
No. This JSON formatter does all parsing and formatting in the browser (client side) with JavaScript. The JSON you enter is never sent to or stored on a server, so you can safely work with sensitive data.
What is JSON minify?
Minifying removes all whitespace, line breaks and indentation to put the JSON on a single line. The meaning stays the same but the size shrinks, which is better for network transfer and storage. Beautifying does the opposite, adding indentation for readability.
How is the error position shown?
If there is a JSON syntax error, the tool analyzes the message thrown by JavaScript's JSON.parse and shows the approximate line and column of the problem. This helps you quickly find missing commas, quotes or closing brackets.
Can I change the indentation width?
Yes. You can choose 2 spaces, 4 spaces or a tab. Format to match your team's code style and then copy the result.
Related tools & guides
Last updated: 2026-06-25