Official specs from Steam

Undertale system requirements

Minimum and recommended PC specs as listed by the developer on Steam. Native macOS version available. Native Linux build available.

Undertale release infoSteam page Check other games

Minimum

OS *Windows XP, Vista, 7, 8, or 10
Memory2 GB RAM
Graphics128MB
Storage200 MB available space

Recommended

OS *Windows XP, Vista, 7, or 10
Processor2GHz+
Memory3 GB RAM
Graphics512MB
Storage200 MB available space

macOS minimum

OSMac OS X 32/64-bit
Memory2 GB RAM
Storage200 MB available space

macOS recommended

OSMac OS X 32/64-bit
Memory4 GB RAM
Storage200 MB available space

FAQ

What graphics card do I need for Undertale?

Minimum: 128MB. Recommended: 512MB.

How much RAM does Undertale need?

Undertale needs 2 GB RAM at minimum, 3 GB RAM recommended.

How big is Undertale?

Undertale requires 200 MB available space.

Does Undertale run on Mac or Steam Deck/Linux?

Yes, there is a native macOS version. A native Linux build is available.