Formateador JSON

Pega JSON a la izquierda y obtén una versión embellecida o minificada a la derecha. Los errores de validación muestran la ruta y un mensaje corto. Nada sale de tu navegador — es seguro pegar credenciales. 

// la salida aparece aquí

Inactivo. Pega JSON para comenzar.

About this tool

JSON Formatter pretty-prints, minifies, validates, and analyses JSON in your browser. It detects syntax errors with caret-positioned messages, supports a configurable indent (2 or 4 spaces, tabs), and can sort object keys alphabetically for stable diffs. The analyser reports the top-level shape, the depth of the deepest nested object, the count of keys, the count of arrays, and the total size in bytes and UTF-8 characters. Parsing uses the native JSON.parse, so the tool follows the ECMA-404 spec exactly — no extensions, no comments, no trailing commas.

When to use it

  • Pretty-printing a minified JSON response from curl or a logs dashboard
  • Validating a JSON file before pasting it into a config or shipping it in a release
  • Sorting keys alphabetically to make a config diff easier to read in code review
  • Auditing a JSON document's structure before writing a parser for it

When not to use it

  • You need JSON5, NDJSON, or JSONC with comments and trailing commas — those have separate tools on the site
  • You need to edit a JSON document interactively — paste it into a real editor with JSON support
  • You need to transform JSON with a query (jq) — this formats, it does not query

Frequently asked questions

Does it support JSON5 or comments in JSON?

No. It parses strict ECMA-404 JSON. If your file uses // comments, trailing commas, or unquoted keys, the parser will reject it — those are JSON5 features, not JSON. Use the JSON5-aware tools for that.

How big a JSON file can I paste in?

The tool handles files up to about 5 MB comfortably on a modern laptop. Larger files work but the pretty-print can take a few seconds. The paste buffer is held in memory only — refresh the page and it is gone.

Does it round-trip through the original formatting?

No. Pretty-printing is a one-way operation: the output follows the chosen indent and the chosen key order. If you need lossless round-tripping, the source editor is the right tool.

← Back to the homepage · More guides · More from the blog