Online Regex Tester: Debug & Build Patterns Fast
Building complex Regular Expressions can be challenging. Our Online Regex Tester provides a real-time environment to test, debug, and understand your patterns. Whether you're a developer writing code or an SEO professional filtering Google Search Console data, our tool gives you the precision you need.
Why Use Our Regex Checker?
Unlike simple testers, DevPeak offers a comprehensive suite of features to make pattern matching easier:
- Live Highlighting: See matches and capture groups instantly as you type.
- Regex Explainer: Get a detailed breakdown of what every token in your pattern does.
- Interactive Debugger: Step through the matching process to find exactly where things go wrong.
- Code Generation: Export your working regex to JavaScript, Python, or PHP snippets instantly.
Regex for SEO
Isolate branded keywords, find question-based queries, or filter specific URL subfolders in GSC and GA4 using advanced patterns.
Multi-Engine Testing
Switch between JavaScript and PCRE2 engines to ensure your regex works perfectly in your specific environment.
Privacy-Centric
We process all data client-side. Your regex patterns and test strings never leave your browser.
Regex Cheat Sheet & Common Patterns
^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$
Mastering basic tokens is the first step. Here are some essentials:
^: Matches start of the line.$: Matches end of the line.\d: Matches any digit.[a-z]: Matches any character in range.(a|b): Matches 'a' or 'b'.
Frequently Asked Questions
What is Regular Expression (Regex)?
A Regular Expression, or Regex, is a sequence of characters that forms a search pattern. It is used for string matching, searching, and replacing text in almost all programming languages and many SEO tools like Google Search Console.
How do I test Regex for Google Search Console (GSC)?
In GSC, you can use Regex filters in the Performance report. Select 'Query' or 'Page', then choose 'Custom (regex)' from the dropdown. Use our tester to validate your pattern before applying it to ensure you capture the correct data.
Is this Regex Tester tool private and secure?
Yes, our Regex Tester processes everything locally in your browser. Your test strings and patterns are never sent to our servers, ensuring your data remains 100% private.
Which Regex engines do you support?
Our tool supports multiple engines including JavaScript (native), PCRE2 (via WebAssembly), and has optional support for Python-style patterns, allowing you to test compatibility across different environments.
What are common Regex tokens for SEO?
Common tokens include '.' (any character), '*' (zero or more), '+' (one or more), '^' (start of string), '$' (end of string), and '|' (OR operator). These are essential for filtering branded vs. non-branded queries.