Format JSON online, validate JSON syntax, minify payloads, sort keys and inspect parse errors in your browser.
JSON (JavaScript Object Notation) is a strict text format: keys and string values must use double quotes, there are no trailing commas, comments are not allowed, and the top level is a single object or array. This JSON formatter and validator re-indents valid JSON so the structure is readable and points to the line and column where parsing fails.
Beautify expands the document with consistent indentation and one value per line — ideal for reading and diffing. Minify strips every non-essential character to produce the smallest payload for transport. Sort keys helps compare API responses and configuration files. All parsing runs entirely in your browser; the JSON you paste is not uploaded.
No. Parsing, formatting, minifying, sorting and validation all run client-side in your browser using the native JSON engine. Nothing is sent to a server.
The usual culprits are trailing commas, single quotes instead of double quotes, unquoted keys, or comments — all valid in JavaScript objects but not in JSON. The error message points to the exact line and column where parsing stopped.
It recursively reorders every object's keys alphabetically before formatting. This makes two JSON documents directly comparable in a diff even when the original key order differed.
Everything runs in your browser, so the practical limit is your device memory. Documents up to a few megabytes format instantly; very large files may take a moment to build the tree view.