How do I test a regex pattern?

Enter your regex pattern in the pattern field and your test string in the text area. All matches are highlighted in real time as you type.

What regex flags are supported?

All standard JavaScript flags: g (global), i (case insensitive), m (multiline), s (dotAll), u (unicode) and y (sticky). Toggle each with one click.

How do I see capture group values?

When your pattern includes capture groups (parentheses), each group's matched value is shown separately, numbered from left to right.

Can I test against multiline text?

Yes. Paste multiline text into the test area. Use the m flag to make ^ and $ match the start and end of each line rather than the entire string.

Is there a library of ready-made patterns?

Yes. Scroll down to the Pattern Library section for 47+ ready-to-use expressions covering email, URL, phone, date, UUID, password and more. Click Load to drop any pattern straight into the tester above.

Is the pattern library free?

Yes. Completely free, works offline.

Regex Tester — Live Matches, Flags & Pattern Library

Test JavaScript regular expressions with live match highlighting, flag toggles and capture groups, or load 47+ ready-made patterns for email, URL, IP and dates.