Best Bivy Sack: A Compact Alternative to A Tent

Best Bivy Sack
Dennis Owens
Written by Dennis Owens

Have you ever considered replacing the weight of your full-sized tent with something light enough to carry comfortably? Why not consider the benefits a bivy sack offers?

The best bivy sack for you would no doubt be a little less spacious than a tent, but it definitely is a great alternative if you are keen on reducing the weight and size of your backpack.

Is A Bivy Worth It? Would You Be Better Off with A Lightweight Tent or A Tarp?

You may feel that a bivy would not be able to give you the space and the comfort a tent or a tarp would offer. Contrary to this belief, there are bivies that provide enough room to fix up a small meal, read a book, or enjoy some time with your mobile phone.

Though a bivy may not be your choice if you have planned to spend many days in your shelter, it is a fantastic option if you want to get rid of the weight and space your tent or tarp would require. This is due to the lack of poles, doors, and other accessories with a bivy that are absolutely necessary for your tent.

Another advantage of a bivy is that you can use it on any terrain, even in compact spaces like a ledge in a mountain or a little area in the middle of the soft grassy land. Setting it up is very fast and easy; pull it up in a breeze, fit your sleeping bag inside, and crawl up for a cozy night within.

Bivy sack outdoor

And, if you are looking for a solo shelter in the mountains and in snowy weather, a bivy can keep you warmer compared to most lightweight tents.

A lightweight bivy in your backpack can be of a great help if you need to protect yourself in emergency stormy situations in your hike. And, if you enjoy gazing at the stars at night, a bivy is just right for you.

You may also consider using a bivy along with a lightweight tarp setup for added protection. Add a sleeping pad, a pillow, and a sleeping bag for added comfort within a bivy.

Types of Bivies

Different bivies focus on different features.

  • Bug bivies come with nets to keep away bugs. These usually are not meant to be used in harsh weather and primarily focus on protecting you from bug bites.So, these would be for you if you want to camp in fair weather conditions where keeping the bugs away is more important than keeping the rain away. For example, you can benefit from a bug bivy in mosquito infested areas, even if you need to use it indoors.
  • Minimalist bivies are designed for the lightweight backpacker. These may not be 4-season bivies but are great for camping if you are looking for a lightweight and compact option. These can be 3-season, though, and protect you from the elements in your hikes and trips. They are perfect for keeping you dry in emergency rain situations.
  • Four-season bivies usually come with one or two poles to provide more space and are mostly made of high-quality waterproof and breathable material that can also withstand rough conditions without ripping apart. These bivies may be designed to use in high altitudes and stormy weather all the year round.

A Few Factors to Consider When Buying A Bivy

Let’s look at a few features that a bivy could offer.


The material the bivy is made of would depend on the functions it is supposed to achieve in its intended use.

A bug bivy with its net would definitely keep big bugs away, but it would miserably fail if put it to test in the rain. Completely waterproof fabrics like the Gore-Tex would do a great job in keeping even heavy rain away, but these tend to develop condensation, and the bivy needs to have provisions to let it out.

Bivy sack Material

Nylon is a breathable fabric and would prevent condensation from your sweat, and if it is given a waterproof coating, it would withstand rain, but perhaps, not very heavy rain and not as well as waterproof Gore-Tex.

According to the material used, a bivy can be used in stormy alpines or in summer camps with minimal rain chances.


This, obviously, is the crux of choosing a bivy. The bivy you choose should be able to meet your weight requirements. A lightweight bivy with mesh at certain areas may be your go-to bivy if you are looking forward to using one in light rain conditions and reasonably fair weather.

Bivy sack lightweight

A bivy with a pole may come with a few added ounces, but it may be well worth it if you are looking for a compact backpack while trekking the snowy mountains. Don’t forget to consider the packed size of the bivy.


An important thing to consider is the amount of condensation that builds up in a bivy. Contrary to tents, bivies are susceptible to a bit of condensation. Fully waterproof bivies tend to develop more condensation from your sweat as they are fully closed to not allow rain into them.

There may be little options like opening the zippers apart to get it dry again. Some bivies provide poles and stakes. Use them to create maximum space for a reduction in the condensation. Go for breathable fabrics if you do not intend to use the bivy in extreme conditions.


It is easy to feel cramped up in the small space a bivy offers compared to other shelters like tents. It is important, therefore, to ensure the bivy is roomy enough to let you have a comfortable sleep with space to turn and toss around.

Comfort in bivy sack

Consider shoulder width of the bivy and go for one with features like straps to secure your sleeping pad or bag. Wire hoops and poles to keep the fabric away from you will add on to your comfort.

A Few Bivy Sacks You Can Consider – Reviews

Read on to find out more about different bivy sacks and the unique features they offer.

Black Dimaond Hooped Bivy Sack

Black Dimaond Hooped Bivy Sack

Weight: Regular – 1 lb. 10oz; Long – 1 lb.12 oz.

Dimensions: Regular – 90” x 35”; Long – 99” x 35”

Specific Features: 21.75 square ft.(regular)/24 square ft.(long) floor space, ToddTex material, taped seams, no poles, flexible support wires are sewn in, mesh opening

Best Use: For light backpacking and minimalist hiking or camping

Description: Black Diamond’s Hooped Bivy Sack is a lightweight bivy sack with great features. It’s made up of ToddTex, a waterproof, breathable, and abrasion-resistant material. This bivy sack strikes a balance between weight and functionality.

A mesh opening provides breathability. A light cable is sewn in towards the head instead of the use of a tent pole, which somewhat manages to hold shape, though not as well as a pole.  So, it is great to have if you are looking for a good alternative to a tent for your camping.

You need to work on its seams to seal them. The bivy comes with a seam sealant kit which can help you in this process. You may find a bit of condensation in the morning, which is typical of bivy sacks. It may not feel that breathable too in wet weather.

You may also find it not very effective due to cold spots in the winter if you are on the larger side.

Related: Black Diamond Twilight Bivy, Black Diamond Spotlight Bivy

Outdoor Research Bug Bivy

Outdoor Research Bug Bivy

Weight: 16 oz.

Dimensions: 89” x 25” x 18”

Specific Features: Nylon floor with Hydroseal coating, single pole – shock-corded Delrin, no-see-um netting, end zipper, internal mesh pocket, straps for sleeping pad, 3 stake loops, 2 guy line loops

Best Use: Great for bug-free night outs, and lightweight backpacking trips.

Description: The OR Bug Bivy is a lightweight bivy with a netting that keeps you safe from bugs.

It, however, is on the narrow side, so if you end up touching the net, you may be susceptible to a few bites. This bivy has space and the straps to fit in a sleeping pad.

You may also be able to fit a sleeping bag in it. The pole needs to be inserted in a little marked pocket with a piece of Velcro. Once you figure out how to fix the Delrin pole, you will find that putting it up is very fast.

Use the loops to help the pole stand better. Use it with a tarp if you want to keep the rain out. Or, enjoy watching the stars while staying free from bug bites. This bivy can also be used indoors at places where mosquitoes pose a problem. The bivy packs up into a small portable package.

Related: Outdoor Research Helium Bivy, Outdoor Research Molecule Bivy



Weight: 15 oz.

Dimensions: 88” x 36” x 23”

Specific Features: All weather conditions, breathable mesh with zipper, waterproof, 30D nylon breathable fabric, waterproof DuraShield coating on the floor, no pole, fully taped seams

Best Use: For a lightweight shelter in almost any weather condition.

Description: The MSR AC Bivy is made up of a high-quality nylon fabric that is highly water-resistant without a compromise on its breathability.

Thought the laminated nylon fabric is not as waterproof as some other bivies with waterproof fabrics, it performs well in keeping water away and as a bonus, is far more breathable than the other high-end fabrics.

With a shoulder width of 36”, it is spacious enough to allow a comfortable night’s sleep without undue restrictions to move about. You can place your sleeping bag in it, though not strap it in place as there is no such provision.

The zipper on its mesh portion keeps bugs away. It, however, uses an envelope style of closure instead of a zipper at its hood portion.

While this keeps condensation at bay, it may let rain to seep in, compromising on its water-resistant quality. This may also render the bivy not so useful in tough weather conditions like storm and snow. The bivy doesn’t have a pole, thus reducing the space between your head and the mesh.

The best feature of this bivy is its ability to shrink into a truly compact package. This makes it a great option for lightweight backpackers who would like to forego a full-sized tent.

Related: MSR AC Ultralight Bivy, MSR E Bivy

Outdoor Research Alpine Bivy

Outdoor Research Alpine Bivy

Weight: 1 lb. 14 oz.

Dimensions: 84” x 26” x 20”

Specific Features: 3-layer Gore-Tex fabric on top, 70D nylon floor, single shock-corded Delrin pole, no-see-um netting, end zipper with storm flap, internal mesh pocket, loops – 5 stake, 1 guy line, anti-fungal and Hydroseal coating on the floor.

Best Use: A versatile, waterproof, and all-weather-resistant bivy sack

Description: Outdoor Research’s Alpine Bivy is one that can be used in all weather conditions, whether it is in a snowy storm, in the desert, or on a weekend summer trip. It uses three layers of an industry standard Gore-Tex fabric that scores very well in the waterproof/breathable scale.

It uses a high-quality 70D nylon fabric for its floor, which is coated with Hydroseal, which makes it waterproof. Its bathtub shaped floor adds to its versatility by helping to keep dry.

You can pull apart the zippers to create a small opening for ventilation to prevent condensation. Use the stake loops to create enough space between you and the fabric.

The anti-fungal coating on the floor prevents the formation of mold due to condensation. The Alpine gives a spacious feeling because of the Delrin pole; you would not feel suffocated in it when you need to spend a lot of time in bad weather. It gives you enough room to sleep comfortably at night.

If you are large, though, you may not have enough space to store items in it as this bivy is a bit narrow. The Gore-Tex fabric and the pole make this bivy a bit heavy compared to most bivy sacks. If you are ready to put up with a bit of weight, this is a great four-season bivy to own.

Related: Outdoor Research Aurora, Outdoor Research Advanced Bivy

Rab Ridge Raider Bivy

Rab Ridge Raider Bivy

Weight: 2 lb. 3 oz.

Dimensions: 100.4” x 31.5” x 23.6”

Specific Features: 3 layer 40D eVent Exchange Lite fabric, bathtub nylon floor, one DAC Pressfit pole, no-see-um mesh, six V stakes, head door entry, tunnel-shaped

Best Use: Lightweight backpacking

Description: The Rab Ridge Raider is a reasonably spacious bivy that is lightweight with a small footprint; so, you can carry it easily in your backpack on weekend trips and camps. It is made of eVent Exchange Lite fabric, which is both waterproof and breathable.

Though it requires maintenance and regular cleaning, the fabric performs really well in keeping condensation away, rendering the bivy very useful even in rain and wind.

It doesn’t let rain seep through. The bivy is designed like a tunnel with a front entry which may or may not be for you. It features a bathtub nylon floor which manages to keep itself dry.

You may not find enough space to fit in a thick sleeping pad along with a bag, but you can fit in a bag with a thin mattress without getting it all compressed. The DAC Pressfit Pole at the head end of this hooped bivy helps to make the bivy really roomy, so you will not feel claustrophobic in it.

When using the pole, you get enough space at the front end to do little things like sipping coffee, reading, etc. Assembling this bivy is also easy.

Related: Rab Survival Zone Bivy

Moore Militaria Modular Sleep System

Moore Militaria Modular Sleep System

Weight: 9 lb. 4 oz. (total); 2 lb. 4 oz. (bivy sack)

Dimensions: 83” x 36” x 29” (just the bivy); 22” x 14” (combined packed size)

Specific Features: Bivy sack: Gore-Tex, Woodland camo print, no poles, sealed seams; Other components of the system: OD Green Patrol Sleeping Bag ( 30°F), Black Intermediate Sleeping bag(-10°F), black compression stuff sack

Best Use: A complete 4-season sleep system that can be used in any weather from -50°F to 50°F.

Description: The Moore Militaria Modular Sleep System is a complete four-piece set comprising of a water-resistant ripstop nylon polyester filled sleeping bag with temperature rating of 30°F, an intermediate sleeping bag also made of ripstop nylon Polarguard with a temperature rating of -10°F, a bivy sack, and a compression stuff sack to pack them all.

This sleep system is a product from the US military and thus, is of a very high standard. It is compact and well-designed. The bags and bivy give a cozy fit around you. Use the light sleeping bag on its own in warm weather.

For a little more warmth, combine it with the intermediate sleeping bag.

For cold winter and harsh weather, fit both the sleeping bags in the bivy sack for protection against the elements. A great feature of this system is the option to snap the zippers of all the bags together, thus avoiding entangles due to misalignment.

The bivy sack is made of waterproof Gore-Tex fabric which is highly waterproof, wind-resistant, and breathable. It comes with heat-sealed seams. It works well to keep away condensation and dries quickly. You may find it a bit small if you are taller than 6 feet.

The bivy is fast and easy to set up. If you are not as tall as 6 feet, you can manage to fit a mattress in it too for added comfort. The bivy does well to keep you dry in rain, storm, and snow.

Related: Woodland Camo Bivy Cover

Mountain Hardware Dry.Q Core Bivy Sack

Mountain Hardware Dry.Q Core Bivy Sack

Weight: 12 oz.

Dimensions: 86” x 66” x 17”

Specific Features: 30D Nulong Ripstop Dry.Q Core fabric for the top shell, 40D nylon Ripstop fabric for the floor, zipper coated with water-resistant polyurethane, taped seams, drawcord for closing the hood.

Best Use: Minimalist backpacking in the mountains

Description:  Mountain Hardware’s Dry.Q Core Bivy makes good use of a Dry.Q Core membrane which provides a highly waterproof and breathable surface. This, along with the PU coated zipper and taped seams will help you to keep dry in snowy weather.

The strong nylon ripstop fabric will keep the bivy sack intact even on rough surfaces. What’s more! This 3-season bivy is so light, you can easily pack it up in your backpack and go hiking with ease. The bivy can zip onto a compatible mummy sleeping bag which has a 70” zipper.

Finding a little condensation in a bivy is quite normal, but this one dries quite quickly. A few customers have felt that the fabric is not very breathable. As it is very lightweight, you can easily carry it to use as an emergency shelter in harsh weather conditions to keep yourself completely dry.

Related: Mountain Hardware Dry.Q Shark Bivy

Rab Alpine Bivy

Rab Alpine Bivy

Weight: 18 oz.

Dimensions: 92.5” x 31.5” x 11.8”

Specific Features: 3 layer 15D eVent Exchange Lite fabric, two-way zipper, storm flap, taped seams, nylon floor.

Best Use: Minimalist backpacking for hiking in high altitudes and alpines where you need to use a large sleeping bag within it.

Description:  The Rab Alpine Bivy is designed to be used in tough conditions at high altitudes like in summit assaults. The eVent fabric does a fantastic job at keeping you dry in harsh weather without a compromise in its breathability.

The waterproof nylon floor of this bivy will not let water seep through it. This bivy can easily accommodate a fully lofted sleeping bag that’s required for winter camping in the alpines, which makes it suitable for use in the snowy alpines.

It does not have sideway zippers and the entry is through the top portion, which is again typical of alpine bivies.

The storm flap will keep you safe in the event of a storm. This is a spacious bivy and at the same time, packs into a compact and lightweight package into the baffle which can fit in your lightweight backpack.

Related: Rab Storm Spartan Bivi, Rab Ascent Diamond Bivi

So, Which Is The Perfect Bivy for You?

As we have seen, bivy sacks come with a range of features. Choose one based on your intended use. If you are keen on achieving a lightweight backpack, the MSR AC Bivy would be a good choice as it is just 15 ounces and provides good features for the weight.

Choose the perfect bivy for you

If you can withstand a bit of a weight, the Outdoor Research Alpine Bivy is a robust 4-season bivy to have. Another good option for the alpines is the Rab Alpine bivy, which you can use with a large sleeping bag.

If keeping away the bugs in your springtime hike is your main target, go for the Outdoor Research Bug Bivy.

Did you benefit from our reviews? Have you tried to ditch the tent for a lighter bivy sack? We would love to hear about your experiences. Please leave us a comment.

Dennis Owens
Dennis Owens

Dennis Owens is a graduate of National Camping School and REI Outdoor School. He knows everything about what gear to take with you, how to plan your trip to stay safe and what to do if you get lost in the mountains. We are lucky to have Dennis with us as he is a ‘walking encyclopedia’ when it comes to the wilderness.

  • Chase Oliver

    As a lightweight hiker and backpacker who tends to move camp daily, and when looking for something to shelter me from the elements, I typically have three boxes to tick.

    First and foremost, I want something waterproof and capable of adding some measure of warmth/shelter from the cold. Secondly it should be lightweight and finally, it should be a snap to assemble and put away.

    The Alpine Bivy from OR was able to tick all these boxes.

    It is incredibly easy to assemble, simply put together the short pole, insert it into the support sleeve and stake. When packing away, simply reverse the process, fold it up and pack.

    It does provide some measure of warmth and shelter from the elements, I’ve used it in below-zero conditions and even in severe storm weather and woken up dry and warm.

    I’ve been pleased with my purchase from day one and would highly recommend to anyone looking for lightweight shelter.

    • Dennis Owens

      A very comprehensive feedback for the Alpine Bivy, Chase. You managed to highlight all the good stuff, and I agree with everything you said. Overall, this is a great choice and definitely something I would recommend for campers who easily gets cold feet, or wants something that is not too bulky.

  • Adam Hollifield

    I’ve been searching for a 4-season bivy sack for quite some time, and after researching the various products available online, I eventually settled on the Military Modular Sleep System.

    This bag breaks down to offer 4-season options, the lightweight bag can be on its own for warmer nights, with a thicker black bag which can be inserted for cooler nights, and finally, the whole thing can be tucked into canvas bivy for the especially cold nights.

    The various sections snap together on both sides, which is particularly useful, as it prevents them from getting tangled together, you simply line up the zippers and snap.

    I’ve personally only had the opportunity to use this once, on a 4-night camping trip in temperatures at almost zero, and despite the cold, I was able to have a comfortable and warm nights sleep thanks to the sack.

    • Dennis Owens

      Finding a 4-season bivy sack might pose as a challenge because they don’t come as often as conventional bivy sacks. The MMSS (Military Modular Sleep System) is a great choice and I don’t really considering your decision as settling because I think this is a good product to be honest.

  • Brian Edwards

    I stumbled upon Black diamond bivy when it was on discount and bought it immediately. I managed to save money and get my hands on a fantastic bivy sack. I’ve used it during winter and it kept me dry and warm. Although I bought a longer one, it is very light weight. I have a lot of room in it so I can still move around when I need to.

    • Dennis Owens

      That is definitely a steal, Brian. The Black Diamond Bivy sack is an excellent choice, and it will keep you warm and dry even in he most challenging winter camping destinations. What’s more, it is spacious enough not to make you feel congested or cramped.


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