JSON Formatter
Format, minify and validate JSON live — with lenient repair (comments, trailing commas, single quotes), tab indent, precise code-frame errors and a structure summary.
About this ToolHow it works, benefits & use casesTap to collapse
This JSON formatter beautifies, minifies and validates JSON the moment you paste it. Switch between Beautify and Minify with a single toggle: beautify re-indents with 2, 4 or 8 spaces or tabs and can sort object keys alphabetically, while minify strips every byte of optional whitespace. A lenient repair mode lets you feed in near-JSON — single quotes, unquoted keys, trailing commas and // or /* */ comments are normalised before formatting, and a banner tells you when a repair happened. When the input is genuinely invalid, you get a precise code-frame error with the line, column and a caret-marked snippet pointing at the problem. Each successful format produces a structure summary — root type, total keys, maximum nesting depth, and counts of objects, arrays, strings, numbers, booleans and nulls, plus the input byte size. Presets and a local history menu remember your settings and recent inputs, all in the browser.
How to Use
- 1Choose Beautify or Minify with the mode toggle at the top.
- 2In Beautify mode, pick your indentation (2, 4 or 8 spaces or tab) and optionally turn on "Sort keys alphabetically".
- 3Enable "Repair (lenient)" if your input has comments, trailing commas, single quotes or unquoted keys.
- 4Paste your JSON into the input panel — it formats live — or click "Load example" (the example matches your repair setting).
- 5Press "Format JSON" or "Minify JSON" to validate, then copy, download, or share the result.
- 6Read the JSON summary below the output, and recall earlier inputs from the history menu or save option sets as presets.
Key Benefits
- Beautify and minify from one tool with an instant mode toggle
- Lenient repair accepts comments, trailing commas, single quotes and unquoted keys
- Precise code-frame errors with line, column and a caret-marked snippet
- Optional alphabetical key sorting and 2/4/8-space or tab indentation
- Structure summary: root type, key count, max depth, and per-type element counts
- Local history of recent inputs and savable option presets
- Live formatting plus copy, download and shareable URLs — entirely in-browser
Common Use Cases
- Cleaning up an unreadable single-line API response into indented JSON
- Repairing hand-written config or JSON5-style snippets into strict JSON
- Pinpointing a syntax error in a large payload using the line/column code frame
- Normalising key order with alphabetical sorting before diffing two files
- Inspecting the shape of an unfamiliar payload via the structure summary
Options
Accept comments, trailing commas, single quotes, unquoted keys
0 characters · live
Paste JSON above to format it live.
Quick Reference: JSON Formatting Tips
Standard Format
Use 2-space indentation for readability
Validate First
Always validate JSON before formatting
Sort Keys
Enable key sorting for consistent output
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With "Repair (lenient)" enabled, the formatter accepts input that strict JSON.parse would reject: line and block comments, trailing commas, single-quoted strings and unquoted object keys. The input is normalised into valid JSON before formatting, and a green banner appears confirming that a repair was applied.
In Beautify mode you can indent with 2, 4 or 8 spaces, or with a tab character. Minify mode ignores indentation entirely and removes all optional whitespace to produce the smallest valid JSON.