Can swordtails live with gold barbs?

Verdict
Yes

Yes. Swordtails and gold barbs make a good pair. Both are fine at 72–75°F. Plan on at least 30 gal.

SwordtailSwordtail72–79°F · pH 7–8.3 Gold barbGold barb64–75°F · pH 6–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–75°Swordtail 72–79°Gold barb 64–75°
The green band is the temperature range both can live in.
456789Both: 7–8Swordtail 7–8.3Gold barb 6–8
The green band is the pH both tolerate.

Size to scale

Swordtail · 5 inGold barb · 3 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

SwordtailGold barb
Temperature72–79 °F64–75 °F
pH7–8.36–8
Adult size5.0 in3.0 in
Minimum tank30 gal20 gal
TemperamentSemi-aggressivePeaceful
Swims atMiddleMiddle
GroupGroups of 3+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for swordtails

All swordtail tank mates

Better tank mates for gold barbs

All gold barb tank mates

Questions

Can swordtails live with gold barbs?

Yes. Swordtails and gold barbs make a good pair. Both are fine at 72–75°F. Plan on at least 30 gal.

What temperature suits both swordtails and gold barbs?

72–75 °F. Swordtails need 72–79 °F, gold barbs need 64–75 °F.

What size tank do swordtails and gold barbs need together?

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