JSON Formatter - JSON Validator and Formatter
Validate, format and minify your JSON data
Drag and drop JSON file here
Maximum file size: 5MB (.json files)Usage Examples
100% client-side processing. Your data never leaves your browser.
Repair fixes: single quotes, unquoted keys, trailing commas, comments, missing commas, unbalanced brackets.
Usage Examples
API Response Format
Make complex JSON API responses readable and organized.
{"users":[{"id":1,"name":"John","active":true}]}...
Repair Broken JSON
Fix single quotes, unquoted keys, trailing commas, comments and more.
{name: 'John', age: 30, // comment}...
JSON Minification
Optimize JSON file by reducing its size.
{\n "data": {\n "name": "example"\n }\n}...
Features
JSON Validation
Check if your JSON format is valid
Auto Fix
Automatically detect and fix JSON errors
Pretty Formatting
Format JSON in readable format
Minify
Reduce JSON size by removing spaces
How to Use?
Enter JSON
Paste your JSON data into the input area.
Validate and Fix
Check your JSON format. If there are errors, use "Fix" button for automatic correction.
Format/Minify
Click format to make it readable or minify to reduce size.
Use Result
Copy the result or download as a file.
Frequently Asked Questions
What is JSON Formatter?
You paste a JSON response from an API and it is all one line. Good luck reading that. This tool takes that mess and turns it into something you can actually scan through with proper indentation and line breaks. It also catches syntax errors before they waste your time in production.
Key Features
Real-time validation tells you exactly where the problem is -- missing comma on line 42, unmatched bracket, that kind of thing. The auto-fix handles common headaches like single quotes, unquoted keys, and trailing commas. You can pretty-print with 2 or 4 space indentation, or minify everything down to one line when size matters. Drag and drop .json files if you prefer that over copy-paste.
Common JSON Use Cases
If you work with REST or GraphQL APIs, you deal with JSON all day. Same goes for config files like package.json, tsconfig, or ESLint configs. Debugging a webhook payload? Inspecting a MongoDB document? Formatting the raw data is always the first step to figuring out what went wrong.
JSON Formatting Best Practices
Stick with 2 or 4 spaces for indentation -- tabs render differently everywhere. Use camelCase for keys in JS projects, snake_case for Python. Always validate before deploying because one missing comma can break everything. Keep nesting under 4-5 levels deep, and commit the pretty-printed version to git so your diffs actually make sense.
JSON Formatter vs Other Tools
No install, no account, no downloads. Just open the page and paste your JSON. Command-line tools like jq are powerful but you lose the visual feedback -- syntax highlighting and clickable errors make a real difference when you are scanning a large response. Everything runs in the browser so there is zero server latency.
Security and Privacy
Your data stays on your machine. All the parsing, validation, and formatting happens in your browser using JavaScript. Nothing hits a server, nothing gets logged, nothing is stored. So yes, it is safe for API keys, tokens, and anything else you would rather keep private.