Developer Tool
Regex Tester & Matcher
Test and debug your regular expressions in real-time. Supports capturing groups, global matches, case-insensitivity, and live highlighting.
What is a Regular Expression (Regex)?
A Regular Expression, often abbreviated as "Regex" or "RegExp", is a sequence of characters that specifies a search pattern. It is an extremely powerful tool used in software development for searching, matching, and replacing text strings. Whether you are validating an email address, extracting data from a log file, or replacing specific words in a document, regular expressions make complex text processing fast and efficient.
How to use this Regex Tester
Our Regex Tester provides a live, interactive environment to build and debug your expressions safely:
- Pattern: Type your regular expression without the forward slashes (e.g.,
[a-z0-9]+). - Flags: Add flags like
g(global search to find all matches) ori(case-insensitive search). - Test String: Paste the text you want to search through. The matches will instantly highlight in the result box below.
- Capture Groups: If your regex contains capture groups using parentheses
( ), they will automatically be extracted and listed in the match details.
Privacy and Security
This tool is 100% client-side. Your text strings and regular expressions are evaluated directly within your web browser using JavaScript's native RegExp engine. We never send your data to any server, ensuring complete privacy for sensitive logs, API keys, or proprietary code you might be testing.