Pretty-print, validate and minify the languages you work in — JSON, HTML, CSS, JavaScript, XML and SQL — without leaving the browser. 10 tools in one editor — paste your text once and run any of them, or open any tool on its own page. Everything happens in your browser.
The usual causes are a trailing comma, single quotes instead of double, or an unquoted key. The error message names the problem.
Whitespace, line breaks and comments. The meaning of the code is unchanged, but it is no longer comfortable to read.
No. Formatting and validation both run in your browser.
Large inputs work, but the page is doing the parsing, so a multi-megabyte file will feel slow.