Regex Editor & Tester

This regex captures the file extension from a string by matching a literal dot followed by any number of non-dot characters anchored to the end of the input. For example, on 'archive.tar.gz' it captures '.gz', since it matches only everything after the last dot. It's commonly used in scripts to extract, validate, or strip extensions from filenames. Note that a filename ending in a bare dot will match just the '.' with an empty extension.