Regex tester · ECMAScript

Regular expressions

Uses the ECMAScript (JavaScript) regex engine built into your browser, with the same syntax as JavaScript and TypeScript. Nothing you enter is sent to our server.

Pattern ECMAScript

//g

Test text

–

Matches highlighted

Replace

Replacement: $1, $<name>, $& for the whole match

Matches & groups

#	Position	Match	Groups

Pattern library

Cheat sheet

.: any character (except newline)
\d \w \s: digit, word char, whitespace
\D \W \S: the opposite
\b: word boundary
^ $: start / end (of line with m)
[abc] [^abc]: one of / none of
[a-z0-9]: ranges
* + ?: 0+, 1+, 0 or 1
{3} {2,5}: exactly 3, 2 to 5
*? +?: lazy (as few as possible)
(…): capture group → $1
(?<name>…): named group → $<name>
(?:…): group without capturing
a|b: a or b
(?=…) (?!…): followed / not followed by
(?<=…) (?<!…): preceded / not preceded by
\. \\ \/: escape special characters

Other regex flavours

This tester is ECMAScript. Most patterns carry over, but watch for:

PowerShell / .NET: -match and Select-String ignore case by default (use -cmatch / -CaseSensitive). Otherwise nearly identical; .NET adds atomic groups and inline (?i).
grep -P, PHP, nginx (PCRE): Compatible for the basics. Named groups may also be written (?P<name>…).
grep -E, sed -E, awk (POSIX ERE): No \d \w \s (use [0-9], [[:alnum:]_], [[:space:]]), no lookarounds, no lazy *?, no (?:…).
Python re: Named groups are (?P<name>…); in replacements use \g<name> instead of $<name>.