RegexpLint

RegexpLint helps you understand and analyze regular expressions.
We graphically render regular expressions and point out common pitfalls.

Enter a regular expression or try example 1 · example 2 · example 3

Use the table below as a cheat sheet:

`[abc]`	a, b or c	`.`	any single character	`a?`	zero or one of a
`[^abc]`	any character except a, b, or c	`\s`	whitespace	`a*`	zero or more of a
`[a-z]`	range a-z	`\S`	non-whitespace	`a+`	one or more of a
`[a-zA-Z]`	a-z or A-Z	`\d`	any digit	`a{n}`	exactly n of a
`^`	anchor at start of line	`\D`	any non-digit	`a{n,}`	n or more of a
`$`	anchor at end of line	`\w`	any word character (letter, number, underscore)	`a{n,m}`	between n and m of a
`(...)`	capture everything enclosed	`\W`	any non-word character	`a*?`	zero or more of a (non greedy)
`(a\|b)`	a or b	`\b`	any word boundary	`(a)...\1`	back reference
`(?=a)`	look ahead (positive)	`(?!a)`	look ahead (negative)	`\B`	any non-word boundary