Regex Roulette · #41 · 2026-05-15
Match words containing at least one double letter (aa, bb, etc.)
Difficulty 1/3
How to play
Write a regex that matches all green strings and rejects all red strings. Live feedback shows which strings pass. Shorter patterns score better.
Must match
- book — not yet evaluated
- coffee — not yet evaluated
- all — not yet evaluated
- balloon — not yet evaluated
Must not match
- cat — not yet evaluated
- dog — not yet evaluated
- run — not yet evaluated
- test — not yet evaluated
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Pattern body only — slashes and flags (e.g. /g, /i) aren't part of the input.
0/200 chars
Type a regex that matches all green strings and rejects all red strings · Back to hub