REGEX LAB

PCREGo

EXAMPLES

QUICK REFERENCE

Anchors

^start of line / string

$end of line / string

\bword boundary

\Bnon-word boundary

Characters

.any char (s flag: incl. \n)

\d / \Ddigit / non-digit

\w / \Wword char / non-word

\s / \Swhitespace / non-ws

[abc]character class

[^abc]negated class

[a-z]range

Quantifiers

* + ?0+, 1+, 0-1 (greedy)

{n}exactly n

{n,m}n to m (greedy)

*? +? ??lazy (non-greedy)

Groups

(abc)capture group

(?:abc)non-capturing

(?P<n>abc)named capture

Lookaround · PCRE

(?=abc)positive lookahead

(?!abc)negative lookahead

(?<=abc)positive lookbehind

(?<!abc)negative lookbehind

Backrefs · PCRE

\1 \2backref in pattern

$1 $2backref in replace

${name}named group in replace

PATTERN

TEST STRING

REPLACE

■ 2 matches

HIGHLIGHTED

The quick brown fox
jumps over the lazy dog
Pack my box with five dozen liquor jugs

MATCHES

quick

4–9

↳ group 1: "quick"

lazy

35–39

↳ group 1: "lazy"

PCRE-compatible engine (regexp2/v2) — backreferences, lookahead/lookbehind, atomic groups, Unicode. Flags: i=case-insensitive m=multiline s=dot-matches-newline.