JSON Formatter & Validator PRO
Format, validate, and minify JSON instantly. Free online JSON formatter with syntax highlighting, error detection, and copy support.
What is a JSON formatter?
A JSON formatter (also called a JSON beautifier or prettifier) takes minified JSON — one long unreadable line — and expands it into an indented, structured layout you can actually read. It also validates that your JSON is syntactically correct and tells you exactly where errors are.
JSON (JavaScript Object Notation) is the most common data format for APIs, configs, and databases. When you debug an API response or a config file, a good JSON formatter is the first tool you reach for.
Why every developer needs one
API responses arrive minified. Configuration files are often one line. Logs contain embedded JSON. Without a formatter, spotting a missing comma or quote in a 10,000-character JSON blob is nearly impossible. Our validator pinpoints the error position, and the beautifier makes the structure visible at a glance.
Everything runs client-side — paste sensitive API payloads with total privacy.
How to Use
- Paste your JSON into the input box
- Click Format for indented, readable output
- Click Minify to compress to one line
- Copy the result or fix errors flagged by the validator