Regex Tester
Test regular expressions against sample text with real-time match highlighting.
Regular expressions (regex) are patterns used to match character combinations in strings. They are essential for text searching, validation, and manipulation in programming. This tool lets you test patterns against sample text and see matches highlighted in real-time.
Common regex syntax:
. = any character
\d = digit (0-9)
\w = word character (a-z, A-Z, 0-9, _)
\s = whitespace
* = 0 or more
+ = 1 or more
? = 0 or 1
[abc] = character class
^/$ = start/end of string
() = capture group1. Match email addresses
Given: Pattern: [\w.+-]+@[\w-]+\.[\w.-]+
[\w.+-]+ matches the local part (before @)
@ matches the literal @ symbol
[\w-]+\.[\w.-]+ matches the domain
Result: Matches: user@example.com, john.doe+tag@mail.co.uk
2. Extract phone numbers
Given: Pattern: \d{3}[-.]?\d{3}[-.]?\d{4}
\d{3} matches 3 digits
[-.]? optionally matches dash or dot separator
Repeats for all groups
Result: Matches: 555-123-4567, 555.123.4567, 5551234567
3. Validate hex colors
Given: Pattern: ^#?([0-9A-Fa-f]{3}|[0-9A-Fa-f]{6})$
^#? optionally matches leading #
[0-9A-Fa-f]{3} matches 3-digit shorthand
| or [0-9A-Fa-f]{6} matches full 6-digit
Result: Matches: #FFF, #FF5733, aabbcc