Why is my JSON invalid?

The most common causes: trailing commas, single quotes instead of double quotes, unquoted keys, and comments — none of which strict JSON allows. The error message points at the failing position.

Is it safe to paste sensitive JSON here?

Yes — parsing and formatting happen entirely in your browser; the data is never transmitted or stored.

Minification strips whitespace, shrinking payloads (often 20–40%) for faster network transfer. Use formatted JSON for humans, minified for the wire.

JSON Formatter & Validator

Pretty-print messy JSON, validate its syntax, or minify it for production — with precise error messages when parsing fails. Choose 2-space, 4-space, or tab indentation and optionally sort object keys alphabetically for stable diffs. Everything runs locally, so pasting API responses or config files with sensitive data is safe.

Developer Tools

JSON input

Indentation

Sort keys alphabetically

Result

Private by default

This tool runs entirely in your browser. Your data is never uploaded to a server.

How to use

4 clear steps.

Paste your JSON into the input pane.
Click Format (or Minify) — syntax errors are reported with details.
Optionally sort keys and choose the indentation style.
Copy or download the result.

Good to know

Frequently asked questions

Why is my JSON invalid?: The most common causes: trailing commas, single quotes instead of double quotes, unquoted keys, and comments — none of which strict JSON allows. The error message points at the failing position.
Is it safe to paste sensitive JSON here?: Yes — parsing and formatting happen entirely in your browser; the data is never transmitted or stored.
Why minify JSON?: Minification strips whitespace, shrinking payloads (often 20–40%) for faster network transfer. Use formatted JSON for humans, minified for the wire.