Paste JSON.
Adjust the settings for your task.
JSON Formatter
Format, minify and validate JSON directly in your browser.
JSON is processed locally in your browser.
How to use
Choose an action.
Run the tool with its primary action.
Fix an error or copy the result.
Use the result or run it again.
ABOUT THE TOOL
Online JSON Formatter - format and validate
Format, minify and validate JSON directly in your browser.
When it helps
- Readable API response
- Config file validation
How to get a result
- Paste JSON.
- Choose an action.
- Fix an error or copy the result.
How to find common JSON errors quickly
Paste the complete object or array and run formatting. Valid input becomes indented immediately. Invalid input produces an error instead of silently changing the data.
Start near the reported position
A parser often notices a problem just after the character that caused it. Check the preceding property for a missing comma or quote, then verify that every opening brace and bracket has a matching closing character.
- Property names and string values need double quotes.
- Objects use braces and arrays use brackets.
- Items are separated by commas, with no trailing comma at the end.
- JSON does not support comments or JavaScript expressions.
Formatting does not change the data model
Pretty printing changes whitespace, while minification removes unnecessary whitespace. Neither action should change keys, values, or array order. Review sensitive production data before pasting it into any browser tool, even when processing is local.
Frequently asked questions
What does the JSON formatter do?
It validates JSON, expands it with readable indentation, or minifies it into a compact string.
Does my JSON leave the browser?
No. Formatting and validation run locally, so pasted data is not sent to the ToolChill server.
Will it explain invalid JSON?
Yes. The tool reports a parsing error so you can locate common problems such as missing commas, quotes, or brackets.
Does it support comments in JSON?
No. Standard JSON does not allow comments, trailing commas, or unquoted property names. Remove them before validation.