Regex Roulette · #21 · 2026-04-25
Match numbers without unnecessary leading zeros
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
- 0 — not yet evaluated
- 1 — not yet evaluated
- 42 — not yet evaluated
- 100 — not yet evaluated
- 1000 — not yet evaluated
Must not match
- 00 — not yet evaluated
- 01 — not yet evaluated
- 007 — not yet evaluated
- 0123 — not yet evaluated
Loading your progress...
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