Curated library of common regex patterns
Validates standard email addresses
/^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/Matches HTTP/HTTPS URLs
/https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)/Validates IPv4 addresses
/^((25[0-5]|(2[0-4]|1\d|[1-9]|)\d)\.?\b){4}$/Validates full IPv6 addresses
/^([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$/Matches US phone numbers in various formats
/^\+?1?[-.\s]?\(?\d{3}\)?[-.\s]?\d{3}[-.\s]?\d{4}$/Matches international phone numbers (E.164)
/^\+?[1-9]\d{1,14}$/Matches hex color codes (3 or 6 digits)
/^#?([a-fA-F0-9]{6}|[a-fA-F0-9]{3})$/Matches opening and closing HTML tags
/<\/?[a-z][\s\S]*?>/giMatches URL slugs (lowercase, hyphens)
/^[a-z0-9]+(?:-[a-z0-9]+)*$/Validates UUID version 4
/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/iMatches JSON string values
/"(?:[^"\\]|\\.)*"/gMatches positive and negative integers
/^-?\d+$/Matches decimal numbers
/^-?\d+\.\d+$/Matches numbers in scientific notation
/^-?\d+\.?\d*[eE][+-]?\d+$/Matches US dollar amounts
/^\$?\d{1,3}(,\d{3})*(\.\d{2})?$/Matches percentage values
/^-?\d+(\.\d+)?%$/Matches ISO date format
/^\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01])$/Matches US date format
/^(0[1-9]|1[0-2])\/(0[1-9]|[12]\d|3[01])\/\d{4}$/Matches 24-hour time
/^([01]\d|2[0-3]):([0-5]\d):([0-5]\d)$/Matches ISO 8601 datetime format
/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\.\d+)?(Z|[+-]\d{2}:\d{2})?$/At least 8 chars, uppercase, lowercase, digit, special char
/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$/Matches Visa card numbers
/^4[0-9]{12}(?:[0-9]{3})?$/Matches US SSN format
/^(?!000|666|9\d{2})\d{3}-(?!00)\d{2}-(?!0000)\d{4}$/Matches CSS property declarations
/[a-z-]+\s*:\s*[^;]+;/gMatches JS variable declarations
/\b(const|let|var)\s+([a-zA-Z_$][a-zA-Z0-9_$]*)\b/gMatches ES module imports
/^import\s+.*\s+from\s+['"].*['"]/gmBrowse and search a curated library of common regex patterns for emails, URLs, dates, numbers, and more. Test patterns against your input. Free regex reference.