Regular Expression

Flavor

Test String

Enter a pattern to see its explanation.

No matches

^ — Start of string, or start of line with the m flag
$ — End of string, or end of line with the m flag
\b — Word boundary
\B — Not a word boundary
* — Zero or more times
+ — One or more times
? — Zero or one time
{n} — Exactly n times
{n,} — At least n times
{n,m} — Between n and m times
. — Any character except line terminators
\d — Any digit character (0-9)
\D — Any non-digit character
\w — Any word character (letter, digit, underscore)
\W — Any non-word character
\s — Any whitespace character
\S — Any non-whitespace character
[abc] — Any one of the characters a, b, or c
[^abc] — Any character except a, b, or c
[a-z] — Any character in the range a to z
(abc) — Capturing group
(?:abc) — Non-capturing group
(?<name>abc) — Named capturing group
\1 — Backreference to capture group 1
| — Alternation (OR)
g — Global — find all matches instead of stopping after the first
i — Case-insensitive matching
m — Multiline (JS) / Dotall (Ruby/Python) — ^ and $ match line boundaries or . matches newlines, depending on flavor
s — Dotall — . also matches newlines
u — Unicode — enables full unicode matching
x — Extended (Ruby/Python) — ignore whitespace and allow # comments in the pattern
y — Sticky — matches only from lastIndex