Regex Tester & Explainer
Test a regular expression, live
A regex tester lets you check a pattern against sample text and see exactly what it matches. Type a pattern and some text below — matches highlight instantly, capture groups are listed, and each token in your pattern is explained in plain English. Everything runs in your browser; nothing is uploaded.
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Frequently asked questions
What is a regex tester?
A regex tester lets you type a regular expression and sample text, then instantly highlights matches and shows capture groups — so you can confirm a pattern works before putting it in code.
What does \d mean in a regular expression?
\d matches any single digit 0–9. Its opposite \D matches any non-digit. Similarly \w matches word characters and \s matches whitespace.What's the difference between the g, i, and m flags?
g (global) finds all matches; i (ignore case) makes matching case-insensitive; m (multiline) makes ^ and $ match each line.