Fix and explain a broken regex
Paste a regex that is not matching what you expect and get the fix plus an explanation of what went wrong.
A regex that almost works is maddening: it matches most of your inputs but misses one, or matches one it should not. The bug is usually a greedy quantifier, an unescaped character, or an anchor in the wrong place — invisible until you know to look for it.
This tool diagnoses the pattern against your examples, identifies why it misbehaves, and returns a corrected version with the change explained. Instead of randomly adding question marks until it works, you learn the actual cause and ship a pattern that holds.
The tool for this
⁂Regex Generator
Describe what to match and get a correct regex, explained, with examples.
Frequently asked questions
Why is my regex not matching? +
Common causes are greedy quantifiers, unescaped special characters and misplaced anchors. Paste it with examples and the tool pinpoints which.
Does it explain the fix? +
Yes. It tells you what was wrong and why the corrected pattern behaves correctly.
Can I give it failing examples? +
Yes — provide inputs it should and should not match, and the fix targets exactly those cases.
Related tools
⁂Regex Generator
Describe what to match and get a correct regex, explained, with examples.
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