Not all fish play nice.
Check a pair before you buy a fish that won't fit. 16 species on file, every pair scored, sources cited.
🐟 Instant Compatibility Checker
Enter two fish species to see if they can live together safely.
+
16
Fish species
C(16,2)
Pair checks
FishBase.org
Data source
Popular Pair Checks
Betta + Neon Tetra
🟡 CAUTION
Guppy + Corydoras
🟢 GOOD
Angelfish + Neon Tetra
🟡 CAUTION
Oscar + Neon Tetra
🔴 RISKY
Good Fish for Beginners
Forgiving species. Hard to kill in week one.
Betta Fish
semi-aggressive
Neon Tetra
peaceful
Guppy
peaceful
Corydoras Catfish
peaceful
Platy
peaceful
Molly
peaceful
Swordtail
semi-aggressive
Zebra Danio
peaceful
Harlequin Rasbora
peaceful
Bristlenose Pleco
peaceful
Cherry Shrimp
peaceful
How We Calculate Compatibility
1. Water Overlap
Temperature + pH range intersection. No overlap = instant RISKY.
2. Temperament Match
Peaceful+Peaceful=GOOD, Aggressive+Peaceful=RISKY.
3. Size Predation
Large mouth + tiny tankmate = predator risk.
4. Expert Rules
Known conflicts from SeriouslyFish + FishBase.