Can platies live with mollies?

Verdict
Yes

Yes. Platies and mollies make a good pair. Both are fine at 72–80°F. Plan on at least 20 gal.

PlatyPlaty70–80°F · pH 7–8.2 MollyMolly72–82°F · pH 7.5–8.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–80°Platy 70–80°Molly 72–82°
The green band is the temperature range both can live in.
456789Both: 7.5–8.2Platy 7–8.2Molly 7.5–8.5
The green band is the pH both tolerate.

Size to scale

Platy · 2.5 inMolly · 4 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

PlatyMolly
Temperature70–80 °F72–82 °F
pH7–8.27.5–8.5
Adult size2.5 in4.0 in
Minimum tank10 gal20 gal
TemperamentPeacefulPeaceful
Swims atMiddleTop
GroupGroups of 3+Groups of 3+
DietOmnivoreOmnivore

Better tank mates for platies

All platy tank mates

Better tank mates for mollies

All molly tank mates

Questions

Can platies live with mollies?

Yes. Platies and mollies make a good pair. Both are fine at 72–80°F. Plan on at least 20 gal.

What temperature suits both platies and mollies?

72–80 °F. Platies need 70–80 °F, mollies need 72–82 °F.

What size tank do platies and mollies need together?

At least 20 gal, set by the molly. Add space for each extra fish.