JSON Formatter & Validator
Format, beautify, minify and validate JSON online. Shows the exact line and column of syntax errors. Your data stays in your browser.
Runs in your browser Free · No sign-up
Loading tool…
How to use the JSON Formatter & Validator
- Paste your JSON into the input box – it is validated as you type.
- Choose the indentation and click “Format”, or click “Minify” for a compact version.
- Copy the result or download it as a .json file.
About this tool
Paste JSON from an API response, log file or config and get it neatly indented, or minified for production. If something is wrong, the validator tells you where the error is, so you can fix missing commas or quotes quickly.
- Private: your data is processed on your device and never uploaded.
- Free with no account, limits or watermarks.
- Fast: results appear instantly, even offline once the page has loaded.
Frequently asked questions
Why is my JSON invalid?
Common causes are trailing commas, single quotes instead of double quotes, unquoted keys and comments. JSON allows none of these.
Is it safe to paste API keys or private data?
The tool runs entirely in your browser and sends nothing to a server. Still, it is good practice to remove secrets before sharing JSON anywhere.
Related tools
-
Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to text, with full UTF-8 support and an optional URL-safe mode.
Open tool -
URL Encoder & Decoder
Percent-encode text for URLs and query strings, or decode encoded URLs back to readable text.
Open tool -
UUID Generator
Generate random version 4 UUIDs (GUIDs) in bulk – up to 100 at once, with options for uppercase, hyphens and braces.
Open tool -
Password Generator
Create strong, random passwords with 8–64 characters. Choose letters, digits and symbols and see the estimated strength.
Open tool -
Image Compressor
Compress JPG, PNG and WebP images in your browser. Choose the quality, shrink dimensions and download smaller files – no upload needed.
Open tool -
Image Resizer
Resize images to exact pixel dimensions or by percentage, with or without keeping the aspect ratio. Free, fast and private.
Open tool