JSON Formatter

Beautify, validate, and minify JSON data with tree view and syntax highlighting

About this tool

The JSON Formatter beautifies, validates, and minifies JSON. Paste any JSON payload to see it formatted with indentation, collapsible trees, and precise error messages when the syntax is wrong. Copy the cleaned output back to your editor or API client.

How to use

Paste JSON into the input panel.
Click Format to pretty-print with two-space indentation.
If the JSON is invalid, read the error banner to see the exact line and column.
Use Minify to collapse everything into a single line for production use.
Copy the result to your clipboard when you are happy.

Common use cases

Inspecting an API response during development.
Shrinking JSON before embedding it in HTML.
Validating a configuration file before committing.
Reading a compact webhook payload from a log.
Pretty-printing JSON returned by an LLM tool call.

Frequently asked questions

What if the JSON contains trailing commas?

Strict JSON does not allow trailing commas. The validator will mark the offending location so you can remove it.

Does it handle comments?

Standard JSON disallows comments. If your file is JSONC, strip comments first or use a JSONC parser elsewhere.

Is my data sent anywhere?

No. Parsing and formatting run locally in your browser.

Can it format very large JSON files?

Yes, up to several megabytes. Extremely large files may freeze the tab because browsers parse synchronously.