JSON Formatter & Validator
Paste JSON to format, validate, and minify instantly. Real-time error detection, 2 or 4-space indent, one-click copy.
Formatted JSON will appear here…About This Tool
Format and validate JSON without leaving your browser
Paste any JSON — from an API response, a config file, or a log — and get instant formatting with syntax validation. Errors are caught in real time with the exact message from the parser so you can fix them immediately.
Need to encode the result for a URL? Use the URL Encoder. Working with text? Try the Word Counter.
Real-Time Validation
Errors are shown instantly as you type, with the exact parser message.
Format & Minify
Prettify for readability or minify to a single line for APIs.
2 or 4-Space Indent
Choose your preferred indentation style from the toolbar.
100% Private
No upload — your JSON is processed locally in your browser.
Quick Start
How to Format JSON
Paste Your JSON
Paste raw, minified, or malformed JSON into the input panel. Validation runs automatically as you type.
Choose Indent Size
Select 2-space or 4-space indentation. The output updates instantly.
Copy or Minify
Click Copy to grab the formatted output, or Minify to collapse it to a single line for use in code.
Use Cases
When to Use JSON Formatter
Formatting and validating JSON is an everyday task for developers, testers, and anyone working with APIs or data.
Debug API Responses
Paste raw minified JSON from an API response and pretty-print it to find issues quickly.
Validate JSON Syntax
Check whether a JSON string is valid before using it in a configuration file or codebase.
Minify for Production
Minify a formatted JSON file to reduce payload size before deploying to a production API.
Config File Editing
Pretty-print a minified config file so you can read and edit it comfortably before re-minifying.
Mock Data Inspection
Format JSON mock data files to verify structure and spot missing or mistyped keys.
Data Analysis Prep
Format raw JSON data exports from databases or tools before parsing or analysing them.
FAQ
Frequently Asked Questions
Does this upload my JSON anywhere?
No. All formatting and validation happens locally in your browser. Your data never leaves your device.
What counts as valid JSON?
Double-quoted keys and strings, no trailing commas, no comments, correct nesting of {} and []. The validator shows the exact error if something is wrong.
What is the difference between Format and Minify?
Format adds indentation for readability. Minify removes all whitespace — useful for APIs and config files.
Why is my JSON showing an error?
Common causes: trailing commas, single-quoted strings, unquoted keys, or missing brackets. The error message will tell you exactly what went wrong.