Compact CampingAir, self-inflating, or foam sleeping pad?
This is a different question from R-value. Warmth is about how well a pad insulates; construction is about how it fails, how small it packs, and what it costs — and for a compact kit, one construction type wins almost every time.
Air pads: smallest, lightest, the compact default
An inflatable air pad packs to roughly the size of a one-litre bottle and weighs the least for a given warmth rating — the site's top pick, the Therm-a-Rest NeoAir XLite, is 350 g and warm enough for three seasons. The trade-off is real but manageable: air pads can puncture on sharp ground, sticks, or a careless step. Carry the small repair patch that comes in the box, and check your pitch for stones and thorns before laying it down. For a compact kit, the comfort-to-size ratio of an air pad beats the alternatives enough that the puncture risk is worth accepting.
Self-inflating pads: tougher, bulkier, largely obsolete for this use case
A self-inflating pad has open-cell foam inside that expands on its own when you open the valve, needing only a few extra breaths to firm up. That foam core makes it more puncture-resistant and comfortable at rest than a pure air pad, but it also makes it heavier and considerably bulkier when packed — the foam does not compress the way empty air does. They still show up in car-camping and older gear collections, but for a pack you carry on your back, modern air pads have mostly closed the comfort gap while staying smaller and lighter.
Foam pads: the one that cannot fail
A closed-cell foam pad is a slab of dense foam with no air chamber at all, so there is nothing to puncture and nothing that can go wrong overnight. It costs little and survives abuse a pack couldn't. The cost is bulk: foam pads are thin (little cushioning) and do not compress, so they usually ride strapped to the outside of a pack rather than inside it. For a compact kit that is the wrong trade — but foam earns a second role as a cheap R-value booster, see below.
Stacking foam under air for winter
You do not have to choose only one. A thin foam pad (about R 2) placed under a three-season air pad (R 3–4) adds roughly to R 5–6 combined — a cheap way to push a summer kit into winter use without buying a dedicated winter pad. The foam layer also protects the air pad's underside from ground punctures, which is a common combination among compact campers who already own a three-season air pad. See our R-value guide for how the numbers stack.
Verdict
Default to an air pad — it is what every compact three-season kit should be built around, and the puncture risk is manageable with a patch kit and basic care. Reach for a foam pad only as a cheap insulation-boosting layer under an air pad, or as a backup that genuinely cannot fail. Self-inflating pads rarely make sense once you are optimising for pack size — see our full sleep system picks.