Best Bivy Sacks of 2026

A portable shelter proves indispensable for multi-day outdoor adventures, granting the freedom to set up camp in various locations without the need to reach traditional accommodation facilities like man-made shelters or huts. While tents are a go-to for their versatility and comfort, they can sometimes be cumbersome for solo adventurers or for those on brief excursions, due to their weight and bulk. In these instances, a bivy sack emerges as an excellent alternative. Not only is a high-quality bivy sack on average twice as light and 30% more compact (when packed) than a comparable two-person tent, but it also offers a swift setup in unfavorable weather conditions. This makes it an ideal choice for those of us seeking efficiency and lightness on the trail. However, it’s important to note that bivy sacks might not be the best option for extended journeys as they offer limited space and comfort, often necessitating that the backpack be stored outside.

In making this selection of the best bivy sacks, we’ve prioritized lightweight and waterproof/breathable materials, ensuring versatility and practicality in a variety of conditions. On this selection there is a bivy sack for every situation – from overnight ultralight alpine missions to multi‑day expeditions.

1. Our Bivy Sack Picks

1. Outdoor Research Helium Bivy
2. Black Diamond Spotlight Bivy
3. Outdoor Research Alpine AscentShell Bivy
4. Black Diamond Big Wall Hooped Bivy
5. Sierra Designs Backcountry Bivy

2. Comparison of Bivy Sacks

Feature/Product	Outdoor Research Helium Bivy	Black Diamond Spotlight Bivy	Outdoor Research Alpine AscentShell Bivy	Black Diamond Big Wall Hooped Bivy	Sierra Designs Backcountry Bivy
Type	Single-wall	Single-wall	Single-wall	Single-wall	Single-wall
Packed Weight	15.8 oz.	1 lb. 7 oz.	1 lb. 3 oz.	2 lbs.	14 oz.
Packed Weight (Metric)	447 g	660 g	549 g	950 g	400 g
Packed Size	11 x 4 in.	4 x 7.5 in.	3.5 x 12 in.	6 x 12 in.	10 x 4 in.
Packed Size (Metric)	30 x 10 cm	10 x 19 cm	8 x 30 cm	15 x 30 cm	25 x 10 cm
Size (Length/Width)	92 x 30 in.	92 x 30 in.	83 x 28 in.	98 x 35 in.	80 x 36 in. (R), 86 x 40 in. (L)
Size - Metric (Length/Width)	208 x 66 cm	234 x 76 cm	210 x 71 cm	251 x 89 cm	203 x 91 cm (R), 218 x 102 cm (L)
Material	2.5-layer Pertex Shield Diamond Fuse	Single-layer NanoShield	3-layer AscentShell	3-layer ToddTex	20-denier Nylon Ripstop (WPB)
Head Area System	Single-Pole System	Single-Pole System	Single-Pole System	Free-Standing ( Flexible Wire	None
Season	4-season	4-season	4-season	4-season	4-season

3. The Selection

Outdoor Research Helium Bivy

Best Overall

Suitable for:

• Hiking
• Mountaineering
• Backpacking
• Alpine Climbing

The Outdoor Research Helium bivy stands out in the world of outdoor gear, earning high praise from both hikers and mountaineers for its exceptional balance between weight and performance. Tipping the scales at a mere 15.8 oz, this bivy sack is an exemplar of lightweight design without compromising on durability or protection. Made from 2.5-layer Pertex Shield Diamond Fuse fabric, it provides fantastic weather protection, comfort, ventilation and breathability, all in a lightweight package. The floor, constructed from robust nylon, enhances the bivy’s durability and water resistance, providing a reliable barrier against the elements. One of the standout features of the Black Diamond Bipod Bivy is its innovative pole system. The included pole can be effortlessly suspended within the sleeve, elevating the fabric above the sleeper’s head to create more space and comfort. This system, coupled with stake loops and no-see-um mesh to fend off pesky insects, offers an optimized sleeping environment. It’s these details that make the Outdoor Research Helium an ideal choice for hikers, mountaineers, and backpackers in search of a dependable, minimalistic shelter for their adventures.

 

Black Diamond Spotlight Bivy

Best for Headroom & Ventilation

Suitable for:

• Hiking
• Mountaineering
• Backpacking
• Alpine Climbing

The Black Diamond Spotlight bivy is a noteworthy alternative to the previously mentioned Bipod, particularly for those prioritizing ultra-lightweight gear for their outdoor excursions. While it offers a comparable amount of space, the Spotlight is constructed from a lighter, though somewhat less robust, fabric. The top portion utilizes Black Diamond’s proprietary single-layer Nanoshield fabric, which, despite its thinness, delivers adequate protection. The floor, made from durable, abrasion-resistant nylon, upholds the bivy’s overall resilience against rough terrain. One of the Spotlight bivy’s key features is the inclusion of a DAC Featherlite pole, which effortlessly raises the fabric above the head area. This design choice not only maximizes interior space—boasting an internal height of 51 centimeters when suspended—but also contributes to the bivy’s compact packed size and minimal weight. Additionally, the bivy sack comes equipped with four stake loops and a no-see-um mesh door, ensuring a bug-free night under the stars. However, it’s important to note that the Spotlight’s main advantage, its extreme lightness, comes with a trade-off. The Nanoshield fabric, while innovative, doesn’t offer the same level of breathability as the ToddTex fabric found in the Bipod bivy. This means that users may experience more condensation issues, a factor we’ve taken into consideration during our reviews. Despite this, for adventurers who value minimalism and lightweight packing above all, the Black Diamond Spotlight bivy presents itself as a compelling option.

 

Outdoor Research Alpine AscentShell Bivy

Best for Expeditions in Severe Weather

Suitable for:

• Hiking
• Mountaineering
• Alpine Climbing
• Emergency shelter

The Outdoor Research Alpine bivy is very popular among hikers and mountaineers because it provides superb weather protection but is at the same time super lightweight – it weighs merely 2 pounds. It is made of a 3-layer AscentShell fabric which offers great tear- and abrasion-resistance. It also provides great weather protection and breathability. Due to high-quality fabric, condensation issues rarely appear in this bivy sack. The floor is made of resilient nylon for increased durability and water resistance. The Outdoor Research Alpine allows you to suspend the fabric above the head as it comes with a pole. The pole comes in a sleeve outside and can be secured with Velcro closures at the bottom. The bivy sack is also equipped with sleeping pad straps, five stake loops, internal mesh pocket and no-see-um mesh to keep the insects out. The Outdoor Research Alpine is perfect for those who want a bivy sack that can withstand severe weather conditions.

 

Black Diamond Big Wall Hooped Bivy

Best for Climbers

Suitable for:

• Hiking
• Mountaineering
• Alpine Climbing
• Emergency shelter

The Black Diamond Big Wall Hooper bivy  differs from the products listed above by design – it is a very minimalistic bivy sack. It features a significantly lower head height than the other products here because it does not use a pole system to suspend the material. Instead it uses a sewn-in flexible wire which suspends the material automatically when the shelter is unpacked. The good thing is that the flexible wire makes the Black Diamond Big Wall Hooped easier and faster to set up. It is made of Todd-Tex waterproof/breathable material. The Todd-Tex material is very similar to Gore-Tex; it uses a PTFE membrane that is bonded to the face fabric and internal fabric (3-layer design). The material provides good weather protection and breathability. Therefore, condensation is rarely an issue. It is also equipped with a dual zipper, no-see-um mesh and taped seams. The Black Diamond Big Wall Hooped is best for climbers who need a minimalistic bivy sack for severe conditions.

 

Sierra Designs Backcountry Bivy

Best Budget Option

Suitable for:

• Hiking
• Mountaineering
• Alpine Climbing
• Emergency shelter

The Sierra Designs Backcountry bivy brings a distinctive approach to portable shelter, emphasizing the concept of minimalism in outdoor gear. This bivy sack is designed with an emergency shelter mindset but does not skimp on essential features. Its streamlined design comfortably accommodates a sleeping pad and features a large U-shaped opening, making it both accessible and practical for quick setups. A standout feature is the bivy’s mesh window panel at the head, a thoughtful addition that greatly enhances ventilation during dry weather conditions. This mesh panel plays a crucial role in mitigating condensation build-up, a common challenge in more enclosed shelters. Constructed with a top layer of WPB 20-denier nylon and a sturdier 30-denier nylon for the floor, the bivy strikes a balance between lightweight portability and durability against the elements. Weighing in at an impressively light 14 ounces and compact enough to take up minimal space in a pack, the Sierra Designs Backcountry Bivy is an exceptional choice for adventurers who prioritize simplicity and efficiency in their gear. Its lightweight and small packed size do not compromise its reliability, making it suitable for trips across a range of conditions. We’ve found in our own experiences that for those seeking a minimalistic yet dependable shelter, the Sierra Designs Backcountry Bivy stands out as a top option, offering peace of mind without the bulk.

 

4. Buying a Bivy Sack – What is important?

Weight

One of the main reasons hikers switch from a tent to a bivy sack is weight. Shelters are typically among the heaviest items in your backpack, so shaving off even half a kilo can make a noticeable difference in comfort and speed on the trail. Most quality bivy sacks weigh under 2 pounds (900 g), and many are significantly lighter. Ultralight emergency models can weigh as little as 150–250 grams, while more protective alpine bivies with poles or wire hoops often land between 400–700 grams. That’s still dramatically lighter than most one-person tents.

However, weight should never be viewed in isolation. A 200-gram emergency bivy might be perfect for fastpacking, alpine ridge traverses, or as a backup shelter—but it won’t offer the same comfort or weather resistance as a heavier four-season model. If you expect prolonged exposure to wind, snow, or cold rain, adding a few hundred grams for better protection and structure is usually worth it. Always ask yourself: Is this my primary shelter or an emergency backup? Your answer should guide your weight tolerance. Read more about why it is important to use lightweight gear in our article Why hike lightweight.

Weather Resistance

Weather protection is arguably the most critical performance factor of any bivy sack. Unlike double-wall tents, bivies use a single-wall construction, meaning the same fabric must block rain and allow moisture to escape. High-end bivies use waterproof/breathable (WPB) fabrics such as Gore-Tex, eVent and Pertex. These materials are treated with DWR (Durable Water Repellent) so water beads off the surface. DWR must be reapplied from time to time for optimal performance. It’s important to understand that no WPB fabric is completely waterproof in prolonged, heavy rain.

If you camp in exposed alpine terrain or winter conditions, choose a fully waterproof fabric with a high hydrostatic head rating and a design that allows you to completely zip and seal the opening. Models intended for four-season use often include storm flaps and reinforced floors made from polyurethane-coated nylon for total ground waterproofing. Lightweight bivies made from coated ripstop nylon or metalized materials can handle light rain and wind but are not designed for extended storms. These are best suited for emergency use, dry climates, or when paired with a tarp. As a rule: if you regularly hike in areas with persistent heavy rainfall, a bivy sack is not the ideal primary shelter.

Condensation and Ventilation

Condensation is the biggest challenge with bivy sacks. Because you are sleeping inside a small, enclosed waterproof shell, your breath and body moisture can accumulate quickly. The balance between weather resistance and breathability is delicate. Highly waterproof fabrics often breathe less efficiently, increasing condensation risk. More breathable fabrics reduce moisture buildup but may compromise weather protection.

Design plays a huge role here. Look for:

• Mesh bug screens that allow partial ventilation
• Two-way zippers so you can “crack” the opening
• Pole or wire systems that lift the fabric off your face
• Pegging points to increase airflow and internal volume

Keeping the fabric away from your mouth significantly improves comfort and reduces the “rain effect” caused by shifting inside a damp bivy. In cold or wet conditions, synthetic sleeping bags can be more forgiving than down because they retain insulation even when slightly damp.

Space and Comfort

A bivy sack is minimal by design, but not all bivies feel equally cramped. Basic models are essentially waterproof covers for your sleeping bag. They are lightweight and compact but can feel restrictive. For some hikers, this “body bag” feeling is acceptable. For others, it becomes uncomfortable very quickly. Poled or wire-supported bivies create headroom, lifting the fabric away from your face and improving both comfort and ventilation. These models allow you to read, adjust gear, or simply breathe more easily during bad weather.

When evaluating space, consider:

• Shoulder width
• Length (especially if you’re tall)
• Head height
• Floor shape
• Pad attachment straps

If you toss and turn at night or plan to spend extended time inside during storms, choose a model with structure and volume. The slight weight increase pays off in dramatically improved livability.

Packed Size

Packed size is one of the biggest advantages of a bivy sack. Dropping from a tent to a bivy can save several liters of pack volume, allowing you to use a smaller backpack or carry additional gear. Ultralight models can compress down to the size of a soda can. Even more protective four-season bivies typically pack far smaller than traditional tents. When comparing models, check whether poles are included in the stuff sack or stored separately. Also consider how easily the fabric compresses. Stiffer waterproof materials sometimes take up more space. For fastpacking, alpine climbing, bikepacking, or minimalist trekking, compact packed size is often just as important as weight.

5. Questions and Answers