logoJSON Reader

JSON Formatter — Format, Validate & Beautify JSON Online

A JSON formatter turns messy or minified JSON into clean, properly indented text. Paste your JSON below and click Format to beautify it instantly — then validate, auto-fix errors, minify, or explore it as a tree, graph, or table, and copy or download the result. Free, private (runs in your browser), no signup.

How to format JSON online

  1. Paste your JSON into the editor, or upload / drag-and-drop a .json file.
  2. Click Format to beautify it with clean indentation.
  3. Use Fix JSON to auto-repair errors, or Minify to compact it.
  4. Switch to Tree, Graph, or Table to inspect the structure.
  5. Click Copy or Download to save the result.

Why use JSON Reader's formatter?

Beautify & minify

One-click pretty-print or compact your JSON to a single line.

Validate & auto-fix

Catch syntax errors instantly and repair common mistakes automatically.

Tree, graph & table views

Explore nested JSON visually and edit it inline.

Transform tools

Stringify, unescape, parse nested JSON, and sort keys.

JSONPath filter

Query and extract exactly the values you need.

100% private

Everything runs in your browser — nothing is uploaded.

What is a JSON formatter?

JSON (JavaScript Object Notation) is a lightweight data format used across APIs, config files, and databases. Raw JSON is often minified onto a single line, which is hard to read. A JSON formatter re-indents that data with consistent spacing and line breaks so its structure is obvious, while a validator confirms the syntax is correct. JSON Reader combines both with a full editor, visual tree and graph views, and one-click transforms — all running locally for speed and privacy.

Related JSON tools

JSON ViewerJSON ValidatorJSON MinifierJSON to CSVJSON CompareXML to JSON

Frequently Asked Questions

Everything you need to know about JSON Reader

Yes. JSON Reader's formatter is completely free with no signup and no usage limits — format, validate, and beautify as much JSON as you like.
Yes. All formatting, validation, and conversion runs entirely in your browser. Your JSON is never uploaded to a server.
Formatting (beautifying) adds indentation and line breaks to make JSON readable. Validating checks that the JSON is syntactically correct and points you to any errors.
Click Fix JSON. It automatically repairs common problems such as trailing commas, single quotes, unquoted keys, and missing brackets.
Yes. Switch to the Tree, Graph, or Table tabs to explore your JSON structure visually, then jump back to the Editor at any time.
You can upload or drag-and-drop JSON files up to 50 MB.