Justools

JSON Formatter

Pretty-print, minify, or validate JSON from APIs and config files so it is easy to read.

Paste JSON below. Nothing is sent to a server.

Free tools that often go together. Everything runs in your browser.

How to use this tool

  1. Paste JSON into the input box.
  2. Click Format for readable indentation, Minify to remove whitespace, or Validate to check syntax.
  3. Copy the output when you are done.

Frequently asked questions

What is a JSON formatter?

JSON is a text format that APIs, config files, and many apps use to store structured data as nested objects and arrays. When JSON is minified or comes back from an API as one long line, it's hard to read by eye. A formatter adds line breaks and indentation to reveal the structure, or does the opposite with Minify to strip whitespace for production use. This tool also validates whether the text is syntactically correct JSON.

Who uses a JSON formatter?

Developers inspecting an API response during debugging, students learning how data is structured in web development, and anyone pasting a config file from a webhook, log, or documentation page that arrived as a single unreadable line.

What is the difference between format and minify?

Format adds line breaks and indentation so nested objects and arrays are easy to read. Minify strips all extra spaces and newlines to produce the smallest valid JSON string, which is what you'd ship in production.

Is my JSON sent to a server?

No. Parsing and formatting happen entirely in your browser tab. We do not log or store what you paste.

Can I format large JSON files?

Very large payloads may slow or freeze the tab because the whole document is held in memory. Split huge files into smaller pieces or use a desktop editor for multi-megabyte logs.

Will this fix invalid JSON?

Validate tells you that parsing failed and roughly where, but it won't guess a missing comma or quote for you. Fix the specific error shown, then format again.

What common JSON errors does this catch?

Trailing commas, missing quotes around keys, unescaped quotes inside strings, and mismatched brackets are among the most common issues Validate will flag.

Processed locally in your browser. Your files are never uploaded to our servers.