JSON Formatter & Validator
Format, validate, and explore JSON data in real-time. Paste your JSON and get instant, beautiful output with syntax highlighting and error detection.
Paste JSON to get started
Or click Sample to try with example data
Free & open tool — no signup required. Your data never leaves your browser.
What Is a JSON Formatter?
JSON (JavaScript Object Notation) is the most widely used data interchange format on the web. A JSON Formatter takes compact or poorly-structured JSON and transforms it into a clean, human-readable format with proper indentation. This makes it dramatically easier to read, debug, and understand complex data structures — whether you're working with API responses, configuration files, or database exports.
How to Use This Tool
- 1Paste your JSON into the left editor panel — or click Sample to load example data.
- 2Formatted output appears instantly in the right panel with syntax highlighting. If your JSON has errors, you'll see the exact line and column where the problem is.
- 3Copy or download the result. Switch between Code and Tree views, or Minify for the smallest output.
Common JSON Errors
Trailing commas
JSON does not allow commas after the last item — e.g., {"a": 1,} is invalid.
Unquoted keys
All keys must be double-quoted strings: {name: "test"} should be {"name": "test"}.
Single quotes
JSON requires double quotes for strings. 'hello' is invalid; use "hello".
Missing brackets
Every { needs a }, and every [ needs a ]. Mismatched pairs cause parse failures.
Invalid escape sequences
Only specific escape characters are valid in JSON strings: \n, \t, \\, \", \/, \b, \f, \uXXXX.