Inflatable hot tubs cost a fraction of hard-shell spas, run on a standard 120-volt outlet and pack away, but heat slowly (often about 2 to 3°F per hour), usually cannot heat while the bubbles run, and last a few seasons. Hard-shell spas heat faster, hold heat better, have real hydrotherapy jets and last many years, but need a dedicated 240-volt circuit and a solid pad. Both need the same water care.
Both types give you hot water and bubbles. The differences are heating, comfort, running cost and how long they last.
Side by side
| Inflatable | Hard-shell | |
|---|---|---|
| Upfront cost | Low | High |
| Power | 120 V plug | Usually 240 V dedicated circuit |
| Heat-up | Slow, about 2 to 3°F per hour on many models | Faster |
| Heat while jets run | Often not | Yes |
| Jets | Air bubbles | Water jets for massage |
| Insulation | Limited | Full foam or thermal |
| Lifespan | A few seasons | Many years |
| Site | Flat, cleared surface | Level pad able to carry full weight |
Running cost
Insulation and a tight cover matter most. Hard-shell spas with good insulation often cost less per month to keep hot than inflatables in cold weather, despite more powerful heaters.
Water care is the same
Spas need frequent testing because the small volume of hot water changes quickly. Keep sanitizer and pH in range, clean or swap filter cartridges regularly and drain and refill every few months. Our pool test kit guide covers testing methods.
Safety
Keep water at or below 104°F, limit soak times, keep the cover locked when not in use, and follow the maker’s guidance for pregnancy and medical conditions.
Browse hot tubs and spas.
Common questions
How long do inflatable hot tubs last?
Often a few seasons with good care. Liners and pumps are the usual failure points.
Can an inflatable hot tub stay up in winter?
Some models are rated for cold weather; many are not. Check the maker's minimum air temperature and use the cover.
What electrical supply does a hard-shell hot tub need?
Most need a dedicated 240-volt GFCI-protected circuit installed by an electrician. Some small plug-and-play spas use 120 volts.
What is the maximum hot tub temperature?
US safety guidance and most spa controls cap water at 104°F.