Regex Tester shows exactly which parts of a text match your regex pattern — highlighted inline with the rest of the text — plus the detail of each match, including capture groups if your pattern uses parentheses.
Regex Tester — MEA Tools
Test a regex pattern right in your browser, with matches highlighted instantly.
Open Regex Tester →Steps to test a regex
- Open tools.meaecosystem.com/regex-tester.
- Type your regex pattern into the pattern field.
- Check the flags you need:
gto find all matches (not just the first),ito ignore case,mfor multiline mode. - Paste or type your test text into the text field.
- Parts matching the pattern are highlighted instantly, and the total match count is shown.
- If your pattern uses parentheses for capture groups, the detail of each match (including each group's content) appears below.
The g, i, m flags — when should you use them?
The g (global) flag is needed when you want to find every occurrence of the pattern in the text, not just the first one found — usually enabled by default. The i flag is useful when you don't care about case, like searching for a word regardless of whether it's written in upper or lower case. The m flag changes how ^ and $ behave so they match the start/end of each line instead of just the start/end of the whole text — useful for multi-line text.
Why doesn't my pattern match even though it looks correct?
The most common cause: forgetting to escape a special regex character (like a period or parenthesis you meant to search for literally, not as regex syntax), or a needed flag that wasn't checked. Try highlighting your test text with a simpler pattern first, then gradually add complexity until you find the problematic part.
Frequently asked questions
Is my pattern and text sent to a server?
No. Regex testing runs directly in your browser using JavaScript's built-in regex engine.
Is every kind of regex syntax supported?
This tool uses the browser's built-in JavaScript regex engine, so the supported syntax follows the JavaScript regex standard — there may be small differences if you compare it to regex in other programming languages like Python or PHP.
What's a capture group?
A capture group is a part of a regex pattern marked with parentheses, used to "capture" and extract a specific part of the matched text, rather than just knowing whether there's a match overall.