10 Best Sleeping Bag Liners 2025 in the United States

The Friendly Swede Sleeping Bag Liner is made of microfiber, providing a cotton-soft feel while being breathable. This liner is designed to add up to 10°F of warmth to your sleeping bag, making it suitable for cold weather. It is generously sized at 41 inches in width and 86 inches in length, including a pillow pocket, which should be ample space for most adults. Weighing in at 500 grams or 17.6 ounces, it is relatively lightweight but may not be the best choice for those seeking ultralight packing options.

For those needing a balance between comfort and portability, it is a good fit. The liner is machine-washable, adding to its ease of care, which is a significant plus for camping trips where staying clean can be challenging. The full-length zipper allows for easy entry and exit, and the durable construction means it can withstand the rigors of outdoor use. It also plays a crucial role in keeping your sleeping bag clean by acting as a barrier against sweat and bacteria.

One drawback might be that while it’s great for adding warmth, it may be less effective in extremely hot conditions compared to liners made specifically for cooling. The lifetime warranty offered by The Friendly Swede adds a layer of assurance for long-term use, making it an appealing option for regular campers.

The Friendly Swede Sleeping Bag Liner Ultralight offers many features that make it an appealing choice for campers and travelers. Made from polyester with a silk-like texture, it feels soft against the skin while effectively wicking away sweat and moisture during warmer seasons. Its lightweight design, weighing only 9.17 ounces (260 grams), makes it very portable and backpacking-friendly. The liner is generously sized at 41 inches by 86 inches, providing plenty of room to stretch and move.

The full-length zipper is a handy feature, making it easy to get in and out of the liner, and the double zipper design ensures smooth operation and durability. Additionally, this liner is machine washable, adding to its ease of care and practicality for regular use. A significant benefit is its ability to keep your sleeping bag and bedding clean, which can extend the life of your camping gear by protecting it from sweat, bacteria, and other contaminants.

This liner is most suitable for use in summer and spring, as its thin material might not provide adequate warmth in colder conditions. For those prioritizing comfort, portability, and hygiene during warmer months, this sleeping bag liner is a strong contender. The product also comes with a lifetime warranty, suggesting confidence in its durability and quality. On the downside, the thin material might not be ideal for colder weather, and some users might prefer natural fabrics over polyester.

The Sea to Summit Reactor Sleeping Bag Liner is a solid choice for campers and hikers looking to add extra warmth and hygiene to their sleeping arrangements. Made from synthetic Thermolite Pro fabric, it is designed to insulate well and reflect body heat, making it suitable for cold conditions down to 25 degrees Fahrenheit below your comfort range. This feature makes it versatile for all-season use. The drawcord footbox is a thoughtful addition, providing customizable comfort and compatibility with select Sea to Summit sleeping bags, enhancing its usability.

The liner's HeiQ Fresh odor control technology is another plus, ensuring it remains fresh even after extended periods of use. The product's dimensions (78 x 31.5 inches) make it spacious enough for most adults, and its mummy shape offers a snug fit without being restrictive thanks to the stretchy knitted fabric. Weighing just 0.81 pounds, it is lightweight and extremely compact, making it easy to carry and pack for outdoor adventures.

Maintenance is straightforward, although the synthetic material might not be as breathable as natural fabrics. Some users might find the price slightly high compared to simpler liners, but the added warmth, comfort, and durability potentially justify the extra cost. Given its features, it is best suited for those who frequently camp in cooler temperatures and prioritize both warmth and hygiene in their sleeping setup.