Checks for valid UK/British postcodes. There was another on here that had for some reason been upvoted, but it was actually incorrect as it worked on none of my valid own postcodes! Namely that it assumed two letters and a number (BS3) when you can have variations (M20). Allows for an optional spac...

1-15 alphanumeric login name

Matches text within quotes (", ') and escapes the charecters.

Matches any valid JSON object, matches recursively. Passes all JSON test cases I found.

From a (fairly large) list of User Agent strings, extract the OS, Browser, and Device Type.

Captures all fields from a CSV file's line. Can be customized with user-defined field separator and protecting character.

Email address, most used cases

This regex matches only when all the following are true: password must contain 1 number (0-9) password must contain 1 uppercase letters password must contain 1 lowercase letters password must contain 1 non-alpha numeric number...

Attempts to mimic Google search box behavior, returning an array with the separated search strings (that keep the +/- indicator for following operations)

Validates IPv4 IP Address

A quite neat regular expression for URLs, e-mails..., I found on Matthew O'Riordan's blog.

Matches distorted email addresses and converts them back to real ones.