JSON Formatter
Format, minify, and validate JSON with syntax highlighting and error reporting
Input
0 chars | 0 linesOutput
0 chars | 0 linesWhat Does This Tool Do?
The JSON Formatter takes raw or minified JSON data and transforms it into a clean, readable format with proper indentation and syntax highlighting. It can also minify formatted JSON into a compact single-line string, and validate whether your JSON is syntactically correct. Everything runs entirely in your browser — no data is sent to any server.
Features
Format & Prettify
Transform compact or messy JSON into a beautifully indented, human-readable structure with your choice of 2 spaces, 4 spaces, or tab indentation.
Minify JSON
Compress formatted JSON into a single-line compact string by removing all unnecessary whitespace, perfect for reducing payload size.
Syntax Highlighting
Output is color-coded to distinguish keys, strings, numbers, booleans, and null values, making it far easier to scan and understand your data.
Error Detection
Instantly validates your JSON and reports precise error messages including the line and position where the syntax problem occurs.
File Drag & Drop
Drop a .json file directly onto the input panel to load its contents instantly, no file dialogs or manual copy-pasting required.
Copy & Download
Copy the formatted output to your clipboard with one click, or download it as a .json file ready to use in your projects.
How to Use
- Enter your JSON data. Paste or type your JSON into the input panel on the left, or drag and drop a .json file onto it.
- Choose your indentation. Select 2 spaces, 4 spaces, or tabs from the dropdown in the toolbar to control formatting style.
- Click Format / Prettify. The formatted and syntax-highlighted JSON will appear in the output panel on the right with line numbers.
- Validate or minify. Use the Validate button to check syntax without reformatting, or click Minify to compress the JSON into a single line.
- Copy or download the result. Click Copy Output to place the formatted JSON on your clipboard, or Download .json to save it as a file.
- Clear and start over. Click the Clear button to reset both panels and begin with new JSON data.
FAQ
Is my JSON data sent to a server?
No. All formatting, minification, and validation happen entirely in your browser using JavaScript. Your data never leaves your device, making this tool safe for sensitive or proprietary JSON.
What is the maximum JSON size this tool can handle?
There is no hard limit imposed by the tool itself. Performance depends on your browser and device, but most modern browsers handle JSON files up to several megabytes without issues.
What does the Validate button do differently from Format?
Validate checks whether the JSON is syntactically correct and updates the status indicator without reformatting the output. Format both validates and reformats the JSON with your chosen indentation.
Can I use this tool to fix invalid JSON?
The tool reports error details including line and character position to help you locate problems, but it does not automatically fix invalid JSON. You will need to correct the syntax manually based on the error message.
What indentation option should I choose?
Two spaces is the most common convention in web development and keeps the output compact. Four spaces offers more visual separation, and tabs let each developer display their preferred width in their own editor.
Does the tool preserve the order of keys in my JSON?
Yes. The formatter preserves the original key order from your input. It does not sort or rearrange keys during formatting or minification.