Beautify

Indent and re-flow JSON for human reading.

Indent

Input

Output

Minify

Strip whitespace to the smallest valid form.

Input

Output

Validate

Check syntax and pinpoint the first error.

Input

Result

Tree View

Expandable / collapsible structure with type colors.

Input

Tree

Everything runs in your browser ??no JSON ever uploaded. Paste or open a local file via the OS clipboard. Files up to ~5??0 MB tend to work smoothly; very large files may slow the browser.

What This Tool Does

Beautify ??re-indents JSON with 2 spaces, 4 spaces, or tabs.
Minify ??removes whitespace to produce the smallest valid JSON. Useful for embedding in URLs, configs, or reducing payload size.
Validate ??uses the browser's native parser; on failure shows the error message and (where the engine provides it) line/column.
Tree View ??renders objects and arrays with collapsible nodes and type-colored values, useful for browsing large nested structures.

JSON Quick Reference

JSON (JavaScript Object Notation) is a text format for data exchange. Strict rules differ slightly from JavaScript object literals:

Keys must be in double quotes ??single quotes are not allowed.
Strings must use double quotes ??backslash-escaped Unicode (횞) is permitted.
No trailing commas in arrays or objects (a common parse-error culprit).
No comments ??line or block comments are invalid in strict JSON.
Numbers don't allow leading + or trailing decimals (+5 and 5. are invalid).
Special values Infinity, NaN, and undefined are not part of JSON.

Common Parse Errors

Unexpected token ??usually a stray comma, missing comma, single quote, or unquoted key.
Unexpected end of input ??a bracket or brace was not closed.
Bad escape ??a backslash followed by something other than ", \, /, b, f, n, r, t, or u+4 hex digits.

Privacy

This page is a single static HTML file. No analytics, no network calls, no upload. Your JSON only exists in the textarea until you close the tab.