What is a Regex Tester?
A regex tester lets you write a regular expression pattern and test it in real time against any text. It highlights all matches directly in the text and lists each match with its position and any capture groups. This makes it easy to build, debug, and understand regular expressions without switching between tools.
How to Use the Regex Tester
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Type a regular expression pattern into the pattern field (without slashes).
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Type or paste your test string into the text area below.
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Toggle flags as needed: g (global), i (case-insensitive), m (multiline), s (dot-all).
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Matches are highlighted in the text automatically as you type.
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Review the match list below to see each match's value, position, and capture groups.
This free regex tester runs entirely in your browser — no data is sent to any server. Use it to build and validate patterns for form validation, text parsing, search-and-replace, and more. Supports all JavaScript-compatible regular expression syntax.
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