DEV JSON

JSON Formatter and Validator

Paste JSON to validate its syntax and format it with two or four spaces. The data stays in your browser and is not uploaded.

✓ Free to use✓ Files stay on your device✓ No signup required

Format JSON

Paste a JSON value or document to validate it.

JSON input

Indentation

Enter JSON to check its syntax.

Formatted output

HOW IT WORKS

JSON Formatter and Validator in three steps

Choose your input.Select a file, type your content or enter image dimensions.
Adjust the options.Pick the format, size or quality that fits your task.
Download or copy.Check the result, then save it to your device.

PRACTICAL NOTES

Validate and format JSON data

Paste a JSON value or document and select the indentation. The tool reports browser parser errors and formats valid JSON. It does not send your data to a server.

HELP & ANSWERS

Frequently asked questions

Does the formatter upload JSON?+

No. Formatting and validation run in your browser.

Can it format invalid JSON?+

No. The page reports a syntax error until the input is valid JSON.

Can I choose indentation?+

Yes. Choose two or four spaces for the formatted output.