Formalint

Browser-based developer tools

Regex Tester

Test JavaScript regular expressions, inspect matches and review capture groups without sending text to a backend.

Open JWT decoder

Pattern

Ready

Matches

Ready

JSON FormatterValidate and inspect JSON XML FormatterFormat and convert XML Timestamp ConverterUnix time and ISO dates

Reference notes

Regex checks for everyday parsing

JavaScript flavor

Formalint uses the browser's JavaScript regular expression engine, so results match what front-end code and many Node.js tools will produce.

Capture groups

Each match lists capture groups so you can quickly confirm whether your parser extracts the fields you expect.

Local test data

Input stays in the browser in this static release, which keeps small debugging samples fast and convenient.