JSON Formatter & Validator
Paste messy JSON to beautify, minify, and validate it instantly. Everything runs in your browser, so your data never leaves your machine.
JSON engine. Nothing is uploaded or logged.About the JSON Formatter & Validator
The JSON Formatter & Validator pretty-prints, minifies, and validates JSON so you can read it clearly and confirm it is well-formed before using it. It is built for developers, WordPress and API integrators, and anyone working with config files, REST responses, or data exports. Everything runs 100% in your browser using the native JSON engine, so your data stays private and is never uploaded.
How it works
- Paste or type your JSON into the input area.
- Choose an indent style (2 spaces, 4 spaces, or tab) and click Beautify to format it, or Minify to compress it.
- Review the syntax-highlighted output along with the key/item count and byte size; if the JSON is invalid, read the error message to find the problem.
- Click Copy to grab the formatted result.
Features
- Beautify (pretty-print) and minify with one click.
- Validation with clear error messages, including line and column when the browser provides them.
- Syntax highlighting and selectable indentation: 2 spaces, 4 spaces, or tab.
- Live key/item count and byte size so you can see the structure and weight at a glance.
- One-click copy of the output.
Frequently asked questions
Is my data uploaded anywhere?
No. All formatting and validation happen entirely in your browser using its native JSON engine. Nothing is sent to a server or logged.
What's the difference between beautify and minify?
Beautify pretty-prints your JSON with indentation and line breaks so it's easy to read. Minify removes all unnecessary whitespace to produce the smallest valid JSON, which is useful for storage or transfer.
Why is my JSON invalid?
Common causes are trailing commas, missing or mismatched quotes and brackets, single quotes instead of double quotes, or unquoted keys. The error message points to the issue, and shows the line and column when your browser provides that detail.
Does it work offline?
Once the page has loaded, the formatting and validation run locally in your browser, so the tool keeps working without an active connection.
Is there a size limit?
There is no fixed limit set by the tool. Because processing happens in your browser, very large files are constrained only by your device's available memory and may format more slowly.