Validation notes
JSON does not allow trailing commas, comments, unquoted keys, or single-quoted strings. Duplicate keys are accepted by JavaScript parsers, but the last value wins when parsed.
Input
Output
Formatted output will appear here.
JSON stays on this device. Validation, minifying, key sorting, string escaping, downloads, and the tree view run locally in your browser.
Input
Output
Formatted output will appear here.
Prettify, validate, or paste JSON to inspect it as a tree.
Paste or import JSON above and click Prettify to reformat it with consistent indentation and spacing — free, in your browser, with nothing uploaded to a server. Powered by Prettier.
JSON does not allow trailing commas, comments, unquoted keys, or single-quoted strings. Duplicate keys are accepted by JavaScript parsers, but the last value wins when parsed.
Formatting runs locally and works best for files your browser can comfortably hold in memory. For very large JSON, minify first only if you need a compact copy.
Need to convert Markdown instead? Try the free Markdown to Word/HTML/PDF converter.
Need to run some numbers? Try the free online calculators.
Paste JSON and use Prettify, Minify, Validate, Sort keys, or the JSON string escape tools. Valid JSON can also be inspected in the collapsible tree view.
Yes. The validator reports a best-effort line and column for syntax errors, including common issues like trailing commas.
No. Formatting, validation, minifying, key sorting, string escaping, copying, and downloads run entirely in your browser.
JavaScript formatter · TypeScript formatter · CSS formatter · YAML formatter · C formatter · C++ formatter · VBScript formatter
We use cookies to show ads via Google AdSense. See our Privacy Policy for details.