The 5 Regex Patterns That Cover 80 Percent of Real-World Use Cases

I have been writing regular expressions for 12 years. I use maybe 15 patterns regularly. Five of them cover the vast majority of what I need in production code. These are not the clever ones. They are the patterns that show up in pull requests, log parsers, form validators, and data cleaning scripts week after week. 1. Extract all URLs from a block of text https?://[^\s<>"']+ This matches http:// or https:// followed by any non-whitespace, non-bracket, non-quote characters. It is intentionally loose. A strict URL regex exists (RFC 3986 compliant) and it is 6,300 characters long. Nobody uses it. The loose version catches real URLs in emails, Slack messages, log files, and documentation. It sometimes grabs a trailing period or comma from sentences like "Visit https://example.com ." but trimming punctuation from the end is a one-line post-processing step. const urls = text . match ( /https ? : \/\/[^\s <>"' ] +/g ) || []; I reach for this pattern at least once a week. 2. Validate email fo