Regex Tester – JavaScript Regex Tool
Test Your Regular Expressions in Real-Time
This free online regex tester uses JavaScript’s built-in RegExp engine to match your input. Easily test, debug, and validate regex patterns.
Regex Tester
Regular expressions (or regex) can be super powerful—but also a bit tricky. That’s where our Regex Tester comes in. It helps you write, test, and debug regular expressions in real-time, so you can see exactly how your pattern matches (or doesn’t match) your text.
Whether you’re a developer, student, or just diving into regex for the first time, this tool makes learning and experimenting much easier.
What you can do:
Write and test regex patterns instantly
Highlight matches in real time
Get quick feedback on what works and what doesn’t
Use helpful flags and modifiers for advanced control
Real-life uses:
Validate email addresses or phone numbers
Extract data from logs or text files
Clean up messy data with find-and-replace
Filter search results with precision
No setup, no installation—just a simple, powerful way to master regex.
Beginner-Friendly Regex Examples
Here are a few common patterns to help you get started:
Match an email address:\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b
Match a phone number (e.g. 123-456-7890):\d{3}-\d{3}-\d{4}
Match a 5-digit ZIP code:\b\d{5}\b
Match any word that starts with “re”:\bre\w*
Match any word that starts with “re”:\bre\w*
Find all numbers in a text:\d+
Quick Regex Tips
\d = any digit (0–9)
\w = any word character (letters, digits, underscores)
\s = any whitespace (spaces, tabs, line breaks)
. = any character (except line breaks)
^ = start of a line, $ = end of a line
* = 0 or more times, + = 1 or more times, ? = optional
Pro Tip: Always test your regex with real sample text to see exactly what it matches.