Question 1

What is a regular expression (regex)?

Accepted Answer

A regular expression is a pattern used to match text. It is widely used for email validation, data extraction, string replacement, and more.

Question 2

What do the g, i, m, s flags mean?

Accepted Answer

g (global) matches all occurrences, i (case-insensitive) ignores case, m (multiline) matches across lines, and s (dotAll) makes "." match newlines too.

Question 3

Is my data sent to a server?

Accepted Answer

No. All regex processing happens in your browser. No data is sent externally.

Question 4

What are capture groups?

Accepted Answer

Capture groups are parts of a pattern enclosed in parentheses (). They let you extract portions of matched text and reference them as $1, $2, etc. in replacements.

🔍 Regex Tester

FAQ

Related Tools