Can goldfish live with swordtails?

Verdict
No

No. Goldfish and swordtails should not share a tank. Goldfish are coldwater animals (60–74°F); swordtails need 72–79°F. They overlap only at 72–74°F, the edge of both ranges.

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–74°Goldfish 60–74°Swordtail 72–79°
The green band is the temperature range both can live in.
456789Both: 7–8Goldfish 7–8Swordtail 7–8.3
The green band is the pH both tolerate.

Size to scale

Goldfish · 10 inSwordtail · 5 in0"2"4"6"8"10"
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

GoldfishSwordtail
Temperature60–74 °F72–79 °F
pH7–87–8.3
Adult size10.0 in5.0 in
Minimum tank40 gal30 gal
TemperamentPeacefulSemi-aggressive
Swims atAll levelsMiddle
GroupAlone or in pairsGroups of 3+
DietOmnivoreOmnivore

Better tank mates for goldfish

All goldfish tank mates

Better tank mates for swordtails

All swordtail tank mates

Questions

Can goldfish live with swordtails?

No. Goldfish and swordtails should not share a tank. Goldfish are coldwater animals (60–74°F); swordtails need 72–79°F. They overlap only at 72–74°F, the edge of both ranges.

What temperature suits both goldfish and swordtails?

72–74 °F. Goldfish need 60–74 °F, swordtails need 72–79 °F.

What size tank do goldfish and swordtails need together?

At least 40 gal, set by the goldfish. Add space for each extra fish.