Regex Tester

Writing regular expressions can be a powerful way to work with text, but it often involves a lot of trial and error. Getting the pattern just right requires a good testing environment. For this reason, our free online regex tester provides a live playground to build and debug your patterns instantly.

This tool highlights all matches in real-time. As a result, you can see exactly how your expression works and refine it with confidence.

How to Use the Regex Tester

1. Enter Your Pattern: First, enter the regular expression you want to test into the “Pattern” field.

2. Add Your Text: Next, type or paste the text you want to search against into the “Test String” box.

3. Set Flags (Optional): After that, you can use the checkboxes to enable common flags like g (global) or i (case-insensitive).

4. View the Results: Finally, the tool will instantly highlight all the matches found, showing you exactly what your pattern is capturing.

Regex Tester FAQs

• Q: What is a regular expression (regex)? A: A regular expression is a sequence of characters that specifies a search pattern. For example, developers use it to find, replace, and validate text, which makes it an incredibly powerful utility.

• Q: What do the g and i flags mean? A: The flags modify the search behavior. Specifically, the g flag finds all matches in the text instead of stopping after the first one. On the other hand, the i flag makes your pattern case-insensitive, so ‘Apple’ and ‘apple’ would both match.

• Q: Is the data I enter in the regex tester safe? A: Yes, absolutely. All testing happens directly in your browser. In fact, your patterns and test strings are never sent to our servers, which ensures your data remains completely private.