A complete regex syntax reference — character classes, anchors, quantifiers, groups, lookaround, and flags. Click Try it on any row to open it live in the Regex Tester.

Character Classes

Match a single character from a category or a custom set.

Syntax	Matches
.	Any character except a newline.	Try it →
\d	Any digit (0-9).	Try it →
\D	Any non-digit character.	Try it →
\w	Any word character: letters, digits, or underscore.	Try it →
\W	Any non-word character.	Try it →
\s	Any whitespace: space, tab, or newline.	Try it →
\S	Any non-whitespace character.	Try it →
[abc]	Any one character from the set — here, a, b, or c.	Try it →
[^abc]	Any character NOT in the set.	Try it →
[a-z]	Any character in the range a to z.	Try it →

Anchors

Match a position in the text rather than a character.

Syntax	Matches
^	Start of the string — or start of each line, with the Multiline flag.	Try it →
$	End of the string — or end of each line, with the Multiline flag.	Try it →
\b	A word boundary — the position between a word character and a non-word character.	Try it →
\B	NOT a word boundary.	Try it →

Quantifiers

Control how many times the preceding token can repeat.

Syntax	Matches
*	0 or more of the preceding token.	Try it →
+	1 or more of the preceding token.	Try it →
?	0 or 1 of the preceding token (makes it optional).	Try it →
{n}	Exactly n times.	Try it →
{n,}	n or more times.	Try it →
{n,m}	Between n and m times, inclusive.	Try it →
*? +? ??	Lazy (non-greedy) versions of *, +, and ? — match as few characters as possible instead of as many.	Try it →

Groups & Alternation

Group parts of a pattern together, or match one of several options.

Syntax	Matches
(...)	Capturing group — remembers the text it matched so you can extract it.	Try it →
(?:...)	Non-capturing group — groups a pattern without remembering the matched text.	Try it →
(?<name>...)	Named capturing group — like (...), but accessible by name instead of position.	Try it →
\|	Alternation — matches whatever is on either side of it (like OR).	Try it →
\1	Backreference — matches the exact same text that capturing group 1 already matched.	Try it →

Lookaround

Zero-width assertions — check what's nearby without including it in the match.

Syntax	Matches
(?=...)	Positive lookahead — matches only if followed by the pattern, without consuming it.	Try it →
(?!...)	Negative lookahead — matches only if NOT followed by the pattern.	Try it →
(?<=...)	Positive lookbehind — matches only if preceded by the pattern.	Try it →
(?<!...)	Negative lookbehind — matches only if NOT preceded by the pattern.	Try it →

Flags

Modifiers placed after the closing slash of a regex (e.g. /pattern/gi) that change how it matches.

Syntax	Matches
g	Global — find all matches instead of stopping at the first one.
i	Case-insensitive — ignore uppercase/lowercase differences.
m	Multiline — makes ^ and $ match the start/end of each line, not just the whole string.
s	Dot matches newline — makes . also match line break characters.
u	Unicode mode — treats the pattern as full Unicode code points.
y	Sticky — matches only starting at the exact lastIndex position, without scanning ahead.

Escaping Special Characters

These characters are special to regex — prefix any of them with a backslash to match them literally: . * + ? ^ $ { } ( ) | [ ] \

Syntax	Matches
\.	Escapes a special character so it matches literally — here, a literal dot.	Try it →

Regex Cheat Sheet