💻 Regex Tester — Test Patterns Live
Enter a pattern and flags, paste test text, and see matches highlighted with capture groups explained.
Input
Result
Private by design. This tool runs entirely in your browser — nothing you enter or add is uploaded to any server.
How it works
- Enter your regular expression pattern and optional flags (g, i, m, etc.).
- Paste the text you want to test against.
- Click Test Regex to see all matches and their capture groups.
Examples
- Pattern \b\w+@\w+\.\w+\b with flag gi finds email addresses.
- Use capturing groups like (\d{4})-(\d{2})-(\d{2}) to extract date parts.
- The global flag g finds every match instead of only the first.
Frequently asked questions
Which regex flavor is used?
JavaScript's native RegExp engine, so lookbehind and other modern features work where the browser supports them.
Are my patterns or text sent anywhere?
No. Matching runs entirely in the browser.
How do I see capture groups?
Each match line shows the full match followed by any numbered or named groups.
Related tools
More Developer tools →UUID Generator
Generate cryptographically random UUID version 4 identifiers.
Cron Expression Explainer
Turn a five-field cron expression into plain language and upcoming run times.
CIDR Subnet Calculator
Find the IPv4 network, broadcast, usable hosts, and subnet mask for any CIDR prefix.
URL Inspector
Break an absolute URL into protocol, host, path, query pairs and hash.