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 MongByYa Sleeping Bag Liner stands out with its high-quality polyester material, which is skin-friendly and breathable. This material also benefits from sanding technology, making it softer and resistant to crinkling, pilling, or fading, thus ensuring durability.

The liner's dimensions (82.7” x 70.9”) are generous, accommodating two persons comfortably, and it is lightweight at 31 ounces (approximately 1.5 pounds). This makes it highly portable, as it can be folded into a compact size for easy packing and storage in a convenient carrying bag. The humanized design includes two top buckles for easy access and an invisible bottom zipper for ventilation and free movement of feet, catering to individual comfort preferences.

Additionally, it features a pillow cover on the backside to keep your pillow in place and prevent dirt accumulation, making it highly practical for travel and camping. It's also suitable for all seasons, serving as a supplementary liner in winter or a standalone bag in summer. However, some users might find the polyester material less luxurious compared to natural fabrics like silk or cotton. Furthermore, while it offers a comfortable temperature rating, it might not provide significant warmth in very cold conditions. This liner is ideal for travelers and campers looking for a lightweight, durable, and easy-to-care-for option that provides extra comfort and hygiene on the go.

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.