Can guppies live with swordtails?

Verdict
Yes

Yes. Guppies and swordtails get along in the same tank. Both are fine at 72–79°F. Plan on at least 30 gal.

GuppyGuppy72–82°F · pH 6.8–7.8 SwordtailSwordtail72–79°F · pH 7–8.3

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–79°Guppy 72–82°Swordtail 72–79°
The green band is the temperature range both can live in.
456789Both: 7–7.8Guppy 6.8–7.8Swordtail 7–8.3
The green band is the pH both tolerate.

Size to scale

Guppy · 2 inSwordtail · 5 in0"1"2"3"4"5"6"
Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

GuppySwordtail
Temperature72–82 °F72–79 °F
pH6.8–7.87–8.3
Adult size2.0 in5.0 in
Minimum tank10 gal30 gal
TemperamentPeacefulSemi-aggressive
Swims atTopMiddle
GroupGroups of 3+Groups of 3+
DietOmnivoreOmnivore

Better tank mates for guppies

All guppy tank mates

Better tank mates for swordtails

All swordtail tank mates

Questions

Can guppies live with swordtails?

Yes. Guppies and swordtails get along in the same tank. Both are fine at 72–79°F. Plan on at least 30 gal.

What temperature suits both guppies and swordtails?

72–79 °F. Guppies need 72–82 °F, swordtails need 72–79 °F.

What size tank do guppies and swordtails need together?

At least 30 gal, set by the swordtail. Add space for each extra fish.