Regex Tester
Regex Tester is for those moments when a pattern looks right in theory but you still need to prove what it matches, what it misses, and whether the flags change the outcome.
Test regular expressions in the browser, highlight matches instantly, and experiment with common flags without switching tools.
When this tool helps most
- Checking whether an email, URL, or ID pattern matches the right text.
- Testing replacements or extraction patterns before moving them into code.
- Debugging small parsing rules during frontend, backend, or content-cleanup work.
Test patterns and highlight matches instantly
Useful for validation, extraction, and quick debugging when you need to see what a regular expression really matches.
Common flags
g global, i case-insensitive, m multiline, s dotAll, u unicode.
Highlighted result
How to use Regex Tester
- 1 Enter the regular expression pattern and any flags you want to test.
- 2 Paste the sample text into the input area and run the test.
- 3 Review the highlighted matches and the match count before moving the pattern into your code or workflow.
Frequently asked questions
Does this support common regex flags?
Yes. You can test common JavaScript-style flags such as global, case-insensitive, and multiline.
Is this a full language-specific regex debugger?
No. It is a lightweight browser-side tester for practical pattern checks, especially for JavaScript-style regular expressions.
Can I use this to validate input patterns?
Yes. It is useful for quickly checking whether a validation pattern matches the inputs you expect.
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