Check a card number's format and Luhn checksum, and identify its network.
Test a regular expression against sample text and see every match.
Check a password's real strength: spots common words, look-alike swaps, sequences, keyboard patterns and years, with crack-time estimates.
Check whether a string is a well-formed IPv4 or IPv6 address.
Check an IBAN's format and mod-97 checksum.
Check whether a domain name follows valid label formatting rules.
Check a phone number's digit count and character format.
Parse an existing cron expression into a plain-English schedule description.
Check whether an email address matches a valid format.
Check whether a URL is well-formed and see its parsed components.
Parse a User-Agent string to identify the browser and operating system.
Check a card number's format and Luhn checksum, and identify its network.
Test a regular expression against sample text and see every match.
Check a password's real strength: spots common words, look-alike swaps, sequences, keyboard patterns and years, with crack-time estimates.