← Gear database

Therm-a-Rest Hyperion 20 vs Western Mountaineering AlpinLite 20

Weight and specs compared for 2026 — and which one to choose.

Therm-a-Rest Hyperion 20 is the lighter option — 312 g lighter than the Western Mountaineering AlpinLite 20 (35% less weight). If grams matter to you, that is the one to beat.
shopping_cart Check today's price on Amazon
Spec Therm-a-Rest Hyperion 20 Western Mountaineering AlpinLite 20
Weight 567 g · 0.567 kg · 1.25 lb 879 g · 0.879 kg · 1.94 lb
Brand Therm-a-Rest Western Mountaineering
Category Sleep System Sleep System
Therm-a-Rest Hyperion 20
567 g

900-fill Hyperdry down mummy sleeping bag rated to 20F/-6C. 10D ripstop nylon shell with DWR treatment. Regular size.

Full details →
Western Mountaineering AlpinLite 20
879 g

Roomy 20F mummy bag with 850+ goose down and continuous baffles, balancing warmth, comfort and low weight.

Full details →

HikeLoad is reader-supported. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Learn more.

Therm-a-Rest Hyperion 20 vs Western Mountaineering AlpinLite 20: which should you buy?

If saving weight is your priority, the Therm-a-Rest Hyperion 20 wins — at 567 g it is 312 g (35%) lighter than the Western Mountaineering AlpinLite 20 (879 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.

See where both rank against everything else in this category on the lightest sleep system page, or browse the full gear weight database.

More sleep system comparisons

Therm-a-Rest Hyperion 20 vs Sea to Summit Aeros Ultralight Pillow Therm-a-Rest Hyperion 20 vs Sea to Summit Aeros Ultralight Pillow (Regular) Therm-a-Rest Hyperion 20 vs NEMO Fillo Elite Therm-a-Rest Hyperion 20 vs Nemo Fillo Elite Wide UL Therm-a-Rest Hyperion 20 vs Nemo Equipment Tensor Elite Ultralight Therm-a-Rest Hyperion 20 vs NEMO Equipment Tensor Elite Sleeping Pad