Regex Roulette · #7 · 2026-04-11
Match valid-looking IPv4 addresses (4 dot-separated number groups)
Difficulty 2/3
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
- 192.168.1.1 — not yet evaluated
- 10.0.0.1 — not yet evaluated
- 255.255.255.0 — not yet evaluated
- 0.0.0.0 — not yet evaluated
Must not match
- 1.2.3 — not yet evaluated
- 1.2.3.4.5 — not yet evaluated
- abc.def.ghi.jkl — not yet evaluated
- 1234.1.1.1 — 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