This regular expression validates if given string is formatted in Base64, additional it accepts new lines, since payload can have new lines in it.

Extract all Steam Keys from a Given String

Awesome explanation of nested lookbacks

Validates hexadecimal color codes based on the following rule set: Optionally starting with a hash. 3 or 6 characters in length. Using the [0-9a-f] character set.

Check if brazilian names are imputed correctly. Ex: Paulo da Silva

Valid and Invalid emails

Validate a Json Web Token (JWT).

validator voor kenteken vb: 11-AA-BB

parse the apache access log

fjk@1Qaa$

Matches version strings.

This regular expression will match an IPv4 address as well as both compressed or uncompressed IPv6 address.

matches both function declarations and expressions in javascript. ex. function name () {...} || function () {}

Validates that a DNS hostname is well-formed only. You will still need to check that the overall length of the hostname, including the implied trailing "." (if not present), does not exceed 255 bytes.