any character, line breaks included
Matches any character, line breaks included. It is anchored at both ends, so the whole string has to match. There are no capture groups.
Pattern
/^a.b$/s- Match scope
- the whole string
- Capture groups
- 0
- Flags
- s · dot matches newline
- What it catches in the first example
- a\nb
Try it yourself
Type any text and the parts this expression catches are highlighted. It runs in your browser and is never sent anywhere.
a
b
1 match
Examples that match
- a\nb
- axb
Examples that do not match
- ab
Other expressions in this group
^\u00e9$a character written by code point^Hellotext that starts with this wordworld$text that ends with this word^cat$exactly this word and nothing else\bcat\bthe word on its own, not inside another\Bcatthe word only inside another word^cat$a match that ignores capitals^bthe start of each line, not just the textHow to read this
- With ^ and $ around it, the whole string must match; without them the match can sit anywhere. Always anchor an expression you use for validation.
- Round brackets ( ) capture what they wrap. When you only need grouping, write (?: ) so the numbering of later groups does not shift.
- Every expression here is checked against its examples. Even so, "looks like an email" and "is a real inbox" remain different questions.
- Nested open-ended repeats such as (a+)+ can blow up on certain inputs. Look for that shape before pasting someone else’s expression into your code.
Frequently asked questions
Q. What is the regex for any character, line breaks included?
^a.b$, with the s flag.
Q. Which strings match?
Text like a\nb matches; text like ab does not.
Q. Does the whole string have to match?
Yes. It is wrapped in ^ and $, so nothing but a full match passes.
Q. How do I use what it caught?
There are no capture groups, so only the whole match (match[0]) comes back. Wrap the part you need in brackets to capture it.