JSON Formatter
Format and validate JSON instantly. Free, no login.
JSON was invented by Douglas Crockford in 2001. It was inspired by JavaScript object literals but is now used in virtually every programming language!
How to use the JSON Formatter
Paste raw or minified JSON into the Input panel and click Format to instantly pretty-print it with proper indentation. Use Minify to compress JSON for production use, or Validate to check syntax without transforming the output. The tool shows the number of keys and byte size so you always know what you're working with.
Step-by-step guide
- 1 Paste JSON
Paste your raw, minified, or broken JSON into the Input panel on the left.
- 2 Click Format
Press ⚡ Format or Ctrl+Enter to instantly pretty-print with 2-space indentation.
- 3 Validate
Click Validate to check syntax without modifying the output.
- 4 Copy or Minify
Click Copy to grab the formatted output, or Minify to compress it for production use.
What can you do with this tool?
- Pretty-print minified API responses for debugging
- Validate JSON config files before deployment
- Minify JSON for production payloads to reduce bytes
- Inspect nested JSON structures with readable indentation
- Format JSON copied from browser DevTools network tab
- Check for syntax errors in package.json or tsconfig.json
Why use STB's JSON Formatter?
STB's JSON Formatter is completely free — no account, no email, no credit card. It runs entirely in your browser so your data never leaves your device. Whether you're a developer, student, or just someone who needs a quick json formatter, open this tool and get results in seconds. No ads, no rate limits, no paywalls — just a fast, clean tool from Software That Benefits, a studio dedicated to free tools for developers and students.
Frequently Asked Questions
What is the difference between formatting and minifying JSON?
Formatting (beautifying) adds whitespace, newlines, and indentation to make JSON human-readable. Minifying removes all unnecessary whitespace to produce the smallest possible string — useful for sending JSON over a network where every byte counts.
Why does my JSON fail validation?
Common JSON errors include: trailing commas after the last item in an array or object, single quotes instead of double quotes around strings, unquoted property keys, and comments (JSON does not support comments). The error message in this tool will point to the exact line and character causing the issue.
Can I format very large JSON files?
Yes, within reason. Since the tool runs in your browser, very large files (50MB+) may be slow depending on your device. For files that large, a CLI tool like jq is recommended.
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