DATA / PROCESSED LOCALLY

JSON formatter & validator

Beautify, minify or validate JSON while keeping original numbers intact.

{ }

JSON input

0 charactersUTF-8 text

JSON settings

ActionIndentation

Standard JSON only: no comments or trailing commas. Formatting preserves original number spelling, string escapes, key order and duplicate keys. Validation checks syntax, not a schema.

Local processing · up to 1 MB per input

How it works

Paste your content or open a supported local file.
Choose your settings, then preview or process it.
Copy or download the result. Clear your work when finished.

A few useful details

Syntax validation accepts standard JSON. Formatting keeps original number spelling, string escapes, key order and duplicate keys. It does not validate against a schema.

Up to 1 MB of JSON and 200 nesting levels. Output is capped at 8 million characters, with a shortened on-screen preview for large results. File contents are not saved between visits.

A PRACTICAL GUIDE

When to use JSON formatter & validator

Make JSON readable, remove unnecessary whitespace or check syntax. Formatting preserves the original tokens, including number spelling, string escapes, key order and duplicate keys. This helps inspect a payload without rounding a large identifier during formatting.

Format without rounding an ID

Input: {"id":9007199254740993,"active":true}

Formatted:
{
  "id": 9007199254740993,
  "active": true
}

The original digits remain intact. A downstream application with limited number precision may still round them when parsing.

Frequently asked questions

Are comments and trailing commas allowed?

No. Standard JSON requires double-quoted keys and strings and does not allow comments or trailing commas.

Does it validate a JSON schema?

No. It checks syntax and the tool’s size/depth limits, not field types or business rules. Duplicate keys are retained rather than rejected.

What formatting options are available?

Beautify with two spaces, four spaces or tabs; minify; or validate only. Use up to 1 MB of input and 200 nesting levels. Large outputs have a shortened screen preview.

Still need a hand? Contact the maintainer.