Regex Tester

How to use the regex tester#

Type a pattern between the slashes and some text below it. Matches are highlighted as you type, and Match details lists every match with its position and capture groups. Fill Replace to preview a find-and-replace (use $1, $2 for groups).

Try the ready-made patterns for emails, Indian mobile numbers, URLs, dates and hex colours, then change them to see what happens.

Regex cheat sheet#

Pattern	Means	Example match
.	any character except newline	a, 7, #
\d / \D	a digit / not a digit	5
\w / \W	letter, digit or _ / anything else	a, Z, _
\s	whitespace	space, tab
[abc] / [^abc]	one of / none of	b
a* a+ a?	0+, 1+, 0 or 1 times	aaa
a{3} a{2,4}	exactly 3 / between 2 and 4	aaa
^ $	start / end of the text (or line with m)
\b	word boundary
(...)	capture group	$1 in replace
(?:...)	group without capturing
`a	b`	a or b

Flags#

• g global: find every match, not just the first.
• i ignore case.
• m multiline: ^ and $ match at line breaks.
• s dot-all: . also matches newlines.

Using regex in code#

const emails = "a@x.com, b@y.org".match(/[\w.]+@[\w.]+/g);
console.log(emails); // ["a@x.com", "b@y.org"]

import re
print(re.findall(r"\d{4}-\d{2}-\d{2}", "Due 2026-10-17 or 2026-11-01"))

This tester uses JavaScript’s regex engine. Python’s re module supports the same core syntax shown above.