Regular Expression Tester
foo.*bar), optional flags (e.g. gim), and the text to test below. All matches will be highlighted in real time.Flags:
g (global), i (ignore case), m (multiline), s (dotAll), y (sticky).Example: Pattern
\d+ with flag g will highlight all numbers.Next-Level SaaS Tools — Launching Soon:
About the Regex Tester
The Regex Tester lets you build and debug regular expressions against sample text, highlighting matches in real time so you can see exactly what your pattern catches. It turns the trial-and-error of regex into immediate visual feedback.
Regular expressions are powerful but notoriously hard to get right. Testing a pattern against real examples — and seeing matches and groups highlighted as you type — is the fastest way to nail down a working expression for validation, search, or extraction.
Everything runs in your browser, so your test text never leaves your device. There’s no upload or account; you just write a pattern and watch it match.
How to use the Regex Tester
- Enter your regular expression pattern.
- Paste the sample text you want to test against.
- Set any flags (such as global or case-insensitive).
- Watch the matches highlight in real time.
- Refine the pattern until it matches exactly what you intend.
Common use cases
- Building a pattern to validate emails, phone numbers, or codes.
- Debugging why a regex matches too much or too little.
- Extracting specific parts of text with capture groups.
- Testing a search-and-replace pattern before using it in code.
Frequently asked questions
Does it show capture groups?
Yes. As your pattern matches, you can see what each part captures, which is essential for extraction and replacement tasks.
Which regex flavor does it use?
It uses JavaScript-style regular expressions, which closely match what you’ll use in web and many scripting contexts.
Can I test case-insensitive or multiline patterns?
Yes. Toggle the relevant flags, such as case-insensitive or global, to change how the pattern matches your sample text.
Is my test text uploaded anywhere?
No. Matching happens in your browser, so your text never leaves your device.
Why isn’t my pattern matching?
Common culprits are unescaped special characters or a missing flag. Test against small examples and build the pattern up piece by piece.