Test regular expressions with real-time match highlighting, group capture display, substitution preview, and common regex pattern library — free, instant, browser-based.
🚀 Launch Free Tool →✅ Real-time match highlighting
✅ Capture group display
✅ Substitution / replace preview
✅ Flags: g, i, m, s, u support
✅ Common regex pattern library
A regular expression (regex) is a sequence of characters that defines a search pattern. They are used for text search, validation (emails, phone numbers), and data extraction.
.test() returns true/false (does the pattern match?). .match() returns the matched string or null. Use .test() for simple validation, .match() to extract matched values.
Use \d to match any digit (0–9). For multiple digits, use \d+ (one or more) or \d{3} (exactly 3 digits).