JSON Formatter and Validator

Format a JSON blob for humans, squash it for wire transfer, or find out exactly where a syntax error is hiding — all inside your browser.

How to use

1. Paste JSON from an API response, a log line or a config file.
2. Pretty-print adds two-space indentation; Minify collapses to a single line.
3. Validate reports the first error with a line and column so you can jump straight to it.

Frequently asked questions

Which JSON dialect?

Standard JSON (RFC 8259). Trailing commas and single quotes are not accepted by the browser parser this tool uses.

Will very large JSON crash the tab?

Multi-megabyte payloads work but are slow to render. For huge files, minify first, then only pretty-print the section you need.

Is my data sent to Keyzzone?

No. Parsing and formatting run entirely in this page.