Regex101

Regular expressions, or regex, are a profoundly powerful way of matching patterns in text. Think of “find and replace”—but with profound superpowers like wildcards, boolean “or”, sets, etc. (The Wikipedia entry might help explain some of these concepts, if they’re unfamiliar.)

The best way I can summarize regular expressions are “The Old Magick of Search.” Using them is a bit arcane and fiddly, but they allow you to automate and scale in amazing ways.

Regex101 lets you test your regular expression against some text you upload, plus it provides an explanation, detailed information, and a quick reference for different tokens.

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