Regex Library - Pattern Collection & Tester

Regex Library gives you instant access to 70+ battle-tested regex patterns — no more googling "regex for email" or writing patterns from scratch. ── PATTERN CATEGORIES ── VALIDATION (30+ patterns): • Email addresses (standard, strict, RFC 5322) • Phone numbers (US, international, E.164) • URLs (HTTP/HTTPS, any protocol) • IP addresses (IPv4, IPv6, CIDR notation) • Dates (ISO 8601, US format, European format) • Times (12-hour, 24-hour) • UUIDs (v4, any version) • Hex colors (#RGB, #RRGGBB, #RRGGBBAA) • Semantic versions (semver) • Domain names, MAC addresses • Credit cards (Visa, Mastercard, any with Luhn check) • Passwords (weak, medium, strong) • Usernames, ZIP codes, ISBN EXTRACTION (15+ patterns): • URLs from text • Email addresses from text • Phone numbers from text • Hashtags and @mentions • HTML tags and attributes • Image sources (img src) • Links (href attributes) • Numbers (integers, decimals) • Quoted strings • JavaScript/HTML comments FORMATTING (10+ patterns): • camelCase to snake_case (and reverse) • Whitespace normalization • Line breaks (CRLF, LF, CR) • Words and sentences • CSV fields PROGRAMMING (10+ patterns): • JavaScript identifiers • Python identifiers • SQL keywords • CSS selectors • Import statements • Function declarations ── LIVE TESTER ── • Test any pattern against your text • See matches highlighting in real-time • View capture groups • Try replace patterns • Edit patterns on the fly • Configurable flags (g, i, m) ── CODE SNIPPETS ── • Copy pattern as JavaScript regex • Copy as Python re pattern • Copy as PHP preg_match • Copy as Java Pattern ── FEATURES ── • Search patterns by name or description • Star favorites for quick access • Right-click text to test it • Dark and light themes • Fully offline — patterns bundled locally ── PRIVACY ── Regex Library runs entirely in your browser. Your patterns and test data stay on your machine. No accounts. No analytics. No external servers. ─────────────────────────────────────── Regex Library covers common patterns. DevKit covers everything else. Get 30+ developer tools including regex tester, JSON formatter, JWT decoder, and more. → https://1devtool.com/