JSON Formatter & Validator
Format, validate and beautify JSON online. Find syntax errors by line and column, repair broken JSON and explore it as a tree — all in your browser.
How it works
- 1
Paste or open your data
Paste text, drop a file onto the editor or click Open file. Load sample shows how the tool works.
- 2
Adjust the options
The result updates as you type. Change the options to get exactly the output you need.
- 3
Copy or download
Copy the result to the clipboard or download it as a file.
Why PixNudge
Nothing is uploaded
Your data is processed in your browser and never sent to a server, so API keys, tokens and customer data stay private.
Instant, even for large files
There is no round trip to a server: results appear as you type, and files of several megabytes are handled smoothly.
Exact numbers
Long numbers such as 64-bit IDs are kept exactly as written instead of being rounded.
Frequently asked questions
How do I format JSON online?
Paste your JSON into the input box, drop a .json file onto it or click Open file. It is formatted automatically. Choose 2 spaces, 4 spaces or tabs for the indent, then copy or download the result.
How do I find the error in invalid JSON?
The validator shows the line and column of the first syntax error and underlines it in the editor. Click Show error to jump to it. Common causes are a missing comma, a trailing comma, single quotes and keys without quotes.
What does Repair do?
Repair fixes common problems automatically: it adds missing quotes and commas, removes trailing commas and comments, converts single quotes and Python values such as True and None, and closes unfinished brackets.
Are long numbers kept exactly?
Yes. Numbers are kept exactly as written, so long IDs such as 12345678901234567890 are not rounded the way many other tools round them.
Is my JSON sent to a server?
No. Formatting and validation run in your browser and your data never leaves your device, so it is safe to use with API responses and configuration files that contain private data.