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Best Bivy Sack of 2020

By Brian Martin ⋅ Review Editor
Friday August 21, 2020
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We've tested 16 of the best bivy sacks over the last 6 years. This iteration focuses on nine of the top dogs, compared and contrasted side-by-side. Our testers have used them over all sorts of terrain - hanging off the sides of cliffs, basking in mountain meadows, to sandy, riverside campsites in the desert. We waited out surprise storms at high camps and took them along on climbing, camping, bikepacking, and backpacking missions. With our field tests complemented by objective comparisons, we rate each product using key metrics. Whether you're looking for a great deal of the best when it comes to weather protection, we've got the best choices for you to consider.
Related: Best Ultralight Tents of 2020

Top 9 Product Ratings

Displaying 1 - 5 of 9
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Best Overall Bivy Sack


Outdoor Research Helium Bivy


Editors' Choice Award

$178.95
at Amazon
See It

77
OVERALL
SCORE
  • Weather Resistance - 25% 8
  • Weight - 25% 6
  • Comfort - 20% 9
  • Ventilation - 15% 9
  • Packed Size - 15% 7
Weight: 16.3 oz | Packed size: 4" x 12.5"
Durable
Lots of headroom
Comfortable
Bug Screen and Ventilation
Complete weather resistance
Lightweight
Packed Size

The Outdoor Research Helium Bivy offers fantastic weather protection, comfort, ventilation, and breathability all in a relatively lightweight package. While other models might offer high performance in just one or two areas, the OR Helium is a true all arounder. It performed way above average in every metric we tested. Not only is it packed with features but the entire package comes in at about one pound, poles included. Put simply, it combines everything we want in a bivy better than any other product we've tested.

While we are thoroughly impressed with this bivy, we'll do our best to be objective and point out its flaws. Most importantly is the realization that if you're looking for the burliest and most durable of bivy bags, this isn't it. The OR Helium is intentionally designed to be a lighter-duty version of the OR Alpine, and indeed it is. In a perfect world, you would have a different and specialized bivy for every situation. In the real world, you're probably limited to one, and the OR Helium bivy performed excellently in every situation we threw at it, from heavy rain to not weighing down our pack for extended outings.

Read Review: Outdoor Research Helium Bivy

Best Bang for Your Buck


Sierra Designs Backcountry Bivy


Best Buy Award

$140 List
See It

73
OVERALL
SCORE
  • Weather Resistance - 25% 7
  • Weight - 25% 7
  • Comfort - 20% 7
  • Ventilation - 15% 8
  • Packed Size - 15% 8
Weight: 13.6 oz | Packed size: 3" x 9.5"
Lightweight
High comfort to weight ratio
Breathable
Affordable
Clever stuff sack
Zippers not totally waterproof

The Sierra Designs Backcountry Bivy, a past favorite, proved once again that it's an effective and functional bivy for a wide variety of situations. Although it isn't the lightest or most weatherproof, it does offer features found only in the heavy-duty models, such as a bug screen and an inventive way to prop up the face of the bivy, giving a nice bit of breathing room to the occupant. It's not as comfortable as the OR Helium, but it's close, and the Backcountry Bivy weighs less, which is a bonus.

The Backcountry Bivy isn't a bargain choice, but it provides an impressive price to performance ratio. The clever set of features includes a zippered bug screen, the ability to elevate the bivy face without a pole, and a low overall weight make this piece of equipment stand out against the competition and ensure it can compete with some of the more expensive models.

Read Review: Sierra Designs Backcountry Bivy

Best for Ultralight Protection


MSR Pro Bivy


Top Pick Award

$199.95
at Amazon
See It

68
OVERALL
SCORE
  • Weather Resistance - 25% 6
  • Weight - 25% 8
  • Comfort - 20% 5
  • Ventilation - 15% 6
  • Packed Size - 15% 9
Weight: 8.9 oz | Packed size: 8" x 3.5"
Lightweight and very packable
Simple
Warmth
Ample space
No Closure

The MSR Pro Bivy comes out on top when it comes to weight-to-protection ratio. Weighing in at an impressive 8.9 ounces, the MSR Pro is a fantastic solution for those looking to add an insurance policy to their exposed ridge scramble or ultralight overnight. On the surface, this bivy appears to be something to reserve just for the unexpected emergent rain shower, but depending on your tolerance for discomfort, this could serve as an extremely lightweight shelter for longer excursions.

The Pro Bivy is more of a specialized tool, rather than an all-arounder. If you need a bivy that can hold up to a big storm, check out the Outdoor Research Alpine or Outdoor Research Helium. If you're in the market for a bivy strictly for emergencies, the SOL Escape is our favorite. However, if you're looking for something suited for emergencies as well as ultralight missions into the hills, we think the waterproof fabric, ample footprint, and ease of setup on this model make it a welcome companion.

Read Review: MSR Pro Bivy

Best Emergency Bivy on a Shoestring Budget


SOL Escape Bivvy


Top Pick Award

$59.95
at Backcountry
See It

54
OVERALL
SCORE
  • Weather Resistance - 25% 3
  • Weight - 25% 8
  • Comfort - 20% 4
  • Ventilation - 15% 4
  • Packed Size - 15% 8
Weight: 8.36 oz | Packed size: 4" x 7.5"
Lightweight and packs small
Reflective internal coating
Affordable
Zippers are not waterproof
Short and narrow

The SOL Escape Bivy is a remarkable and simple emergency bivy. We have used ours on and off for over a year, and it's held up well, which is asking a lot from an inexpensive emergency bivy. If you're on a budget and want to make sure you have a little extra warmth and protection in your pack, the SOL Escape is a good choice. If we were recommending a bivy solely upon its price-to-performance ratio, this might be the highest-rated bivy we have ever tested. The proprietary "metalized spun-bonded olefin" fabric proved to be lightweight, very weather-resistant, breathable, and added a significant amount of warmth to the 35-degree sleeping bag used during testing.

If you're venturing into a cold and dry climate, you could certainly get by with the SOL Escape as your primary shelter. Some of our criticisms include the footprint being far too small unless you're under 5'11" and 175 lbs and the inability to fully close the bivy. While the SOL Escape is certainly a far cry from the premium bivys, like the Outdoor Research Helium, it is an excellent emergency shelter that can be used over and over without losing the attributes that make it so functional.

Read Review: SOL Escape Bivy


The Outdoor Research Alpine continues to be our go-to bivy for heavy precipitation and adventures where snow or rain is inevitable.
The Outdoor Research Alpine continues to be our go-to bivy for heavy precipitation and adventures where snow or rain is inevitable.

Why You Should Trust Us


This review is brought to you by OutdoorGearLab Review Editor and multi-discipline outdoor athlete Brian Martin. As a former member of Yosemite Search and Rescue, Brian was tasked with equipment research, testing, and replacement. As a result of this, and a lifestyle centered around a variety of outdoor pursuits, many of which involve spending the night outside in a variety of conditions, Brian has a keen understanding of the finer points in gear. He's as familiar with rock climbing as he is with backpacking or mountain biking, and he brings this familiarity to discern the advantages certain models may have for specific pursuits.

Forty different models were up for consideration before we bought the 8 that are discussed here. We examined how well they protected us from wind and precipitation, as well as how they vented and transferred moisture from inside to out. We also paid attention to packed size, weight, comfort, and compatibility with other items. Testing was conducted in the field, in a variety of environments, from swampy conditions, to snow, to rocky ledges. This review is the distilled knowledge we gained from multiple seasons of intensive testing, and we hope it will serve you well in your own selection process.

Related: How We Tested Bivy Sacks

Swampy campsites are ideal for a bug net bivy sack.
If pitching in a storm consider finding additional shelter  like a rock-cave below a pair of boulders.
Thin but durable zippers and stitching reduce bulk.

Analysis and Test Results


Whether or not to bring a bivy depends on many factors, and everything from weight to the weather forecast to the available space in your pack can influence the decision. Before purchasing a bivy sack, consider the conditions in which you will use it. The high mountains in winter? A boggy swamp in spring? Each of our reviewed products has unique characteristics that might create a compelling reason to consider it for your next outing.

Related: Buying Advice for Bivy Sacks

We were thoroughly impressed with the Outdoor Research Helium's low weight despite its fantastic comfort and protection.
We were thoroughly impressed with the Outdoor Research Helium's low weight despite its fantastic comfort and protection.

Value


We aim to not only bring you the best of the best but the highest value, especially when it comes to performance and cost. Our team of experts put each model through a series of tests, awarding scores for a series of metrics. Determining which bivy will suit your needs will certainly involve a list of pros and cons. What are you looking for? If the best value tops your chart, look for the highest-performing product from our scores that fits your price range. The Sierra Designs Backcountry Bivy, for example, covers what most folks need from such a product (low weight, comfortable, and weather-resistant) without costing as much as most premium models. Or for emergency protection on a budget, the SOL Escape Bivy gives you the extra protection and warmth you might need when the unexpected occurs, but also doesn't put you out a ton of cash. As always, we recommend finding the product that fits your performance needs and financial limitations.


Weather Resistance


From emergency bivys to the ultra-protective alpine expedition models, it's important to have a firm understanding of the characteristics of the bivy you're considering. Does it make sense to have an ultralight emergency bivy as well as an alpine heavyweight? Maybe it makes more sense to have a jack of all trades like the Outdoor Research Helium Bivy. Whatever your needs are, we thoroughly tested each of these bivy sacks within their intended boundaries and beyond to know where their limits really are. Waterproof fabrics and the ability to fully zip and enclose the sacks are a couple of key performance considerations.


Different types of fabrics work best in different situations. A fully waterproof material, like Gore-Tex, will keep all the rain out, but even the most breathable versions have a hard time letting water vapor from sweat and breathing escape. Ripstop nylon is lightweight and waterproof, if treated with a durable water-repellent (DWR) coating. It's typically more breathable, but since it isn't entirely waterproof, it's only ideal for light rain. The SOL Escape deviated from the norm by constructing a bivy from metalized spun-bonded olefin, which is typically used as a moisture barrier for home construction. This material provided excellent weather resistance while maintaining some breathability.

Some bivies are made for four-season protection and can be used in wintry, alpine conditions. Other models strive to save weight and don't allow for a complete closure of the waterproof shell material around the face, so they're best reserved for emergencies or milder rain and temps.

The Gore-Tex fabric on the OR Alpine keeps water and rain out even in the heaviest of storms.
The Gore-Tex fabric on the OR Alpine keeps water and rain out even in the heaviest of storms.

The most weather resistant bivys in our tests were the Outdoor Research Alpine and Outdoor Research Helium. They were fantastically waterproof and offered substantial protection from the elements. If you want the warmest and most heavy-duty bivy for your next alpine excursion, the aptly named Outdoor Research Alpine is your best bet. In our opinion, it has the most durability, warmth, and overall protection. The Black Diamond Bipod is also an impressive model when it comes to protection from the elements.

One of the biggest differences in weather resistance between the Helium (left) and Alpine (right) is the size of the protective flap over the zipper. The Alpine also has a wire sewn in for structure which definitely gives a large weather protection advantage. However  the Helium is quite effective and significantly lighter without this huge flap.
One of the biggest differences in weather resistance between the Helium (left) and Alpine (right) is the size of the protective flap over the zipper. The Alpine also has a wire sewn in for structure which definitely gives a large weather protection advantage. However, the Helium is quite effective and significantly lighter without this huge flap.

The least protective are also often the lightest bivys. Just because they can't keep you warm and dry in a heavy downpour doesn't mean they don't have their place. These lightweight emergency bivys can be worth their weight in gold for fast and light ascents, long trail runs, or fastpacking when some extra protection is warranted.

Like all camping shelters, the way they're used can affect weather resistance. When possible, selecting higher ground or a clearing under a tree will add a bit of extra weather protection and avoid pooling water in a nasty deluge. Always check the trees overhead for dead limbs, or "widow-makers," which can break off dangerously (especially in a storm).

Weight


When hunting for a bivy sack, it's important to take a mindful moment to imagine what exactly you're going to be using it for. Before you look at weights and packed size, make sure the bivy is going to perform at the level you need it to. If you're venturing to a snowy alpine environment with likely precipitation, you want something you can spend a lot of time in comfortably and that you are confident will keep you dry. If you're heading out on a burly all day ridge climb, but aren't sure if you will have to bivouac, a lightweight emergency option might be more appropriate.


If you're breaking into the ultralight game, there are some excellent options available that offer decent protection against those surprise rain showers or windy nights. The lightest reusable bivy is the SOL Escape. The heaviest is the Bipod, which still weighs under two pounds and is far lighter than a standard backpacking tent.

While the MSR Pro does weigh a bit more than the SOL Escape  it offers a significant advantage in comfort and weather protection. Well worth the few extra grams.
While the MSR Pro does weigh a bit more than the SOL Escape, it offers a significant advantage in comfort and weather protection. Well worth the few extra grams.

Comfort


Comfort is always an important criterion for outdoor gear, especially for gear that you rely on for shelter in backcountry situations. Time spent in an uncomfortable or cramped bivy with creepy-crawlies getting inside can turn a user away from bivies for good. The things we considered that contributed to the comfort rating of these each tested bivy included insect protection, roominess (volume and floor plan), ease of use, and added features, such as gear pockets or straps to hold your sleeping pad in place.


Does your sack feel like a sarcophagus? While we might have enjoyed sleeping in cupboards or underneath the bed as children, most grown-ups prefer to have some space to toss and turn throughout the night. If you are choosing a bivy because you want a shelter that weighs less and takes up minimal space in your pack, you should also expect less space for you inside. Just hopefully not to the point of discomfort. We compared not only floor space, but headspace and width at the shoulder, when assessing our comfort ratings.

Compared to the rest of the bivy field  the Superlight Bivy has the most space. This thing is knocking on the door of being a one-person tent.
Compared to the rest of the bivy field, the Superlight Bivy has the most space. This thing is knocking on the door of being a one-person tent.

Ultralight and minimalist models can often be less spacious to cut down on the amount of material used. Conversely, four-season models often have wire hoops or tent poles to help increase volume, leave room for the face, and provide an experience very similar to sleeping under the stars with all the protection of a tent. The Sierra Designs Backcountry Bivy is an excellent combination of size and comfort features such as the ability to keep the ceiling away from your face with no added weight. The SOL Escape is on the snug side but still useable for our 5'11" gear tester.

The extra space created through this simple system was enough for us to read a book and get comfortable during a rainstorm.
The extra space created through this simple system was enough for us to read a book and get comfortable during a rainstorm.

Ventilation


Ventilation in bivys can be a tricky thing. Just like any piece of waterproof gear, typically the better a sack protects you from rain and weather, the less it's able to breathe. How well a bivy ventilates and how much condensation builds up inside is a huge factor in its versatility and performance.


There are a lot of human factors that can make your night miserable even in an exceptional bivy, so here are a few actions you can employ to make sure your bivy will perform to its highest abilities. The main issue is that your condensed breath or extra sweat from getting overheated can build up on the inside of the sack, causing a "rain" effect when moving or shifting inside. One of the easiest things to do to prevent condensation if you have dry weather is to keep the zippers open as much as possible. Even during downpours or extended periods where complete protection is necessary, we recommend "cracking" the mesh or zipper to allow some ventilation of the condensed air inside.

The OR Helium (Left) and OR Alpine (Right) have the same footprint and clam-shell opening/ventilation design. Both allow for ample ventilation during a rainstorm and no-see-um mesh for nicer weather.
The OR Helium (Left) and OR Alpine (Right) have the same footprint and clam-shell opening/ventilation design. Both allow for ample ventilation during a rainstorm and no-see-um mesh for nicer weather.

If dry weather is not in the forecast, the two critical things to keep in mind are to make sure your breath is directed toward the outside of the sack and to use a sleeping bag and pajamas (or whatever clothing you sleep in, if any) that are the appropriate warmth for the temps. If the temps are variable, or you toss and turn in your sleep (and can't easily ensure your mouth stays at the bivy opening), it might be a good idea to bring a synthetic sleeping bag instead of a down sleeping bag. Why? Synthetic insulation will retain its insulating properties and keep you warm if it gets damp or even soaked.

As the entire top portion of the bivy is open  we had no ventilation issues. If you pack along some para-cord  you can elevate the front flap over your head creating a little extra space.
As the entire top portion of the bivy is open, we had no ventilation issues. If you pack along some para-cord, you can elevate the front flap over your head creating a little extra space.

If your bivy can be staked out or has a pole to give you space around the head, taking advantage of these features will add extra air space between your body and the bivy walls, which significantly improves its ability to ventilate. Both the Outdoor Research Helium and Alpine have this feature, which also makes them more comfortable than models that let the fabric rest against your face.

The slight difference of having the bug net/ventilation elevated above your face did two things. It paid huge dividends for comfort  and helped the bivy vent more efficiently.
The slight difference of having the bug net/ventilation elevated above your face did two things. It paid huge dividends for comfort, and helped the bivy vent more efficiently.

Packed Size


No matter what you intend to do with your bivy, packed size is important. Space in our haul bags, backpacks, and bike bags is always at a premium. Having a bivy that is not only lightweight but can also be crammed into a tiny package is essential. By dropping down from a tent to a smaller bivy, you should be able to save several liters of space, allowing for a smaller pack overall or room for other essential gear. Taking this even further, if you opt for an ultralight bivy you might even be able to pack it down to the size of one of those mini coke cans, saving loads of space in your pack.


We measured each product when packed up in its (usually provided) stuff sack. Some of the models have poles that could be added to the same stuff sack or stored in your pack separately. The TACT Frog offers the smallest packed size of all the products tested but it's more of a single-use bivy because it can be easily torn and rendered useless (think giant yard leaf bag).

The TACT is for those wanting to go fast and light and reserve crawling into the bivy for emergency situations.
The TACT is for those wanting to go fast and light and reserve crawling into the bivy for emergency situations.

Conclusion


Climbers and ultralight backpackers alike may be interested in a bivy for numerous reasons. In addition to an emergency shelter, these products can be a lower weight and a smaller alternative to a tent. A bivy can allow you to sleep in a multitude of places where a tent would not be possible. A lot of factors need to be considered when selecting a bivy, ranging from weather resistance to pack size.

Despite the annoyances  the BD Bipod is functional and comfortable.
Despite the annoyances, the BD Bipod is functional and comfortable.

When to Switch from a Tent to a Bivy?


The most common reasons to buy a bivy sack rather than a tent are to reduce pack weight and pack size by utilizing a sleeping system that is both lighter and smaller, yet still able to provide some shelter from the elements. But there is an active debate in the ultralight backpacking community about whether bivy is a better solution than an ultralight tent or tarp shelter. Bivies are still easier to set up than even the best UL tents and tarps, especially if you're looking for a solo shelter equipped to deal with the stormiest weather, and mainly winter snow conditions.

A few salient points:

A tent offers comfort with a lot of floor space which gives you room to sit up, read and hang out, or store gear. An ultralight tarp can also offer a similar amount of room that a tent does, with even lighter weight, and improved protection in the rain over bivies. In a sustained rainstorm, a tent or tarp is much more comfortable than bivies. Many people don't realize that some bivies can give you enough headspace to read or to sit up a bit so you can comfortably sip your coffee or slurp your miso soup.

A tarp can offer excellent weather protection  but only if set up thoughtfully. The two open ends of an A-frame pitch are a liability in wind-driven rain. Ideally  select a campsite where one of the open ends is against a bush or large rock. A superlight water-resistant bivy sack is a good upgrade to augment a tarp and add protection against rain splash or wind spray.
A tarp can offer excellent weather protection, but only if set up thoughtfully. The two open ends of an A-frame pitch are a liability in wind-driven rain. Ideally, select a campsite where one of the open ends is against a bush or large rock. A superlight water-resistant bivy sack is a good upgrade to augment a tarp and add protection against rain splash or wind spray.

Regardless of whether a bivy has those features, some of these traits are not needed by everyone, and they may be worth sacrificing in the name of less weight and space used up in your pack. By shedding extra material, poles, zippers, and doors — bulky components of a tent that are difficult to avoid — a camper can be reasonably comfortable while sitting out poor weather in the smaller enclosed space of a bivy. However, there is a limit to how many hours or days a person can comfortably wait inside a cramped bivy.

For this reason, we recommend that extended backcountry trips with the possibility of poor weather might be better spent in a tent or tarp. For quick trips where a storm can creep up in a moment's notice, or for adventure excursions that require the lightest packs so you can be fast on your feet, a bivy sack can perform and protect as well as a tent.

Indeed, at first glance, a bivy is just a micro-tent, lighter, and smaller with all the protection and less bulk. They are also much more mobile, able to be used on any flat surface long enough to stretch out on, and narrow enough to fit on tight rock ledges and small patches of soft grass. And some bivies don't need trees or anything to anchor them down or guy them out. They can also keep you warmer in cold weather than some tents do, and certainly warmer than a quick tarp setup.

The OR Alpine Bivy (front) can save up to a few pounds off of a typical one-person backpacking tent (back) because it has fewer poles  fabric  and zippers.
The OR Alpine Bivy (front) can save up to a few pounds off of a typical one-person backpacking tent (back) because it has fewer poles, fabric, and zippers.

The bottom line is that you can make a bivy work where a tent will not — high rock ledges, tight snow caves, tiny flat campsites on rocky terrain. Depending on your needs, a bivy can fluctuate from a fraction of a pound to up to two pounds, and even more so in price. While you can now find options for full-sized ultralight tents that are less than two pounds, these tents aren't usually four-season shelters, and they lack the versatility that a bivy sack of similar weight will give you. Another reason people will use a bivy is when they are headed on long adventures and want something to protect them from the elements in an emergency or if they find themselves unexpectedly benighted. Bivies give you the most versatile and lightweight option, and for those who prefer sleeping under the stars, a great alternative to tent camping!

Brian Martin