The Best Ultralight Backpacks of 2020
Best Overall Ultralight Backpack
Gossamer Gear Mariposa
Though we keep testing the latest and greatest on the market, we still have yet to find a pack that can compete with the Gossamer Gear Mariposa. This pack combines comfort and lightweight design in a way that is unparalleled. Its feature set is thoughtful and useful, but not overkill. It provides plenty of external-carry options, without feeling weighed down by superfluous bells and whistles. The Mariposa had our favorite stretchy back mesh pocket, which was large enough to store extra layers, snacks, and other items we wanted to access quickly. It fits a bear canister and can carry a heavy load, but can also be compressed to comfortably carry a smaller load. The fabrics used in its design are durable and lightweight; miles of bushwacking and talus-crossing hardly left a scratch.
Marketed as a 60-liter pack, the Mariposa can carry up to 64 liters when stuffed to the brim. For some, this may feel like too much room for an ultralight pack, as the more room you have, the more you may end up filling with unnecessary gear. It isn't the lightest in our review, though its 2.5-pound total weight and 14g/L weight-to-volume ratio are impressive. Plus, its slightly heavier weight added a level of comfort that was hard to beat.
Read review: Gossamer Gear Mariposa
Best Bang for the Buck
Osprey Exos 48
Though you can find cheaper packs in this review, the Osprey Exos 48 combines durability and excellent features with a relatively affordable price tag, earning it our Best Buy Award. Its variety of pockets, straps, and attachment points allow for plenty of creativity if tinkering is your thing, yet its classic, user-friendly aesthetic works as-is for those who don't feel the need to modify. The Exos carries loads over 20 pounds with ease and excels when loaded down with over 30. The suspension and ventilation of the back panel provide a comfortable, breathable carry for longer missions.
With a measured weight of 2 pounds 5.6 ounces, the Exos just makes the cut as an ultralight pack. It has one of the higher weight-to-volume ratios in our review, but it stands apart from the majority of traditional backpacking packs. Its carrying capacity is relatively small (48 liters), which caters to those with an already trimmed-down kit. We were a little concerned with the long-term durability of this pack, as the stretchy side pockets quickly got holes, but we have no other concerns. The Exos is a tried and true favorite and has been around for a while; this means it is widely available online and in stores and is easy to pick up and take out on your next weekend adventure.
Read review: Osprey Exos 48
Best for Ultralight Enthusiasts
ZPacks Arc Blast 55
The ZPacks Arc Blast 55 is a unique and highly specific pack in that it weighs almost nothing, yet still can carry over 20 pounds. With a measured weight of 21.3 ounces, it's a great deal lighter than most in our fleet. Made from Dyneema Composite Fabric (DFC), the Arc Blast is incredibly durable, though the fabric is a bit stiff and crunchy. Beware of sharp metal edges though (bear canisters or climbing gear), since they can easily wear through the fabric. A relatively recent update includes changes to the straps, pockets, and waist belt. The pack has also seen a carrying-capacity increase from 52 to 55 liters.
The Arc Blast is a slimmed-down ultralight machine, with no bells or whistles. The frame is super-light and super-complicated; we do not recommend removing it unless you want to spend a great deal of time reassembling the pack. The only way to fit a bear canister in this slender pack is vertically, which makes it a bit less efficient to pack. We would recommend this pack to any experienced ultralighter looking to strip a few ounces off their Big Four base weight.
Read review: ZPacks Arc Blast 55
Best for a Small Capacity Model
Ultralight Adventure Equipment CDT
Ultralight Adventure Equipment consistently makes top-notch gear for the ultralight enthusiast, and the CDT is the latest addition to their fleet of durable, lightweight, hardworking packs. This pack is smaller than the previous we've have tested from ULA, but still has many of the signature features that make these packs so well-loved. With a frameless design (a small foam panel for support in the back), the CDT is meant for relatively light, small loads. That said, the waist belt is comfortable, and the materials used in the construction are rugged enough to handle the inevitable beat-down on the trail. Because of its size and design, it's ideal for loads under 20 pounds and will start to feel uncomfortable with 25+ pounds.
What's not to like? Though we loved the feature set of the CDT, it is fairly minimal. This pack is designed for folks who don't like extra frills — there are minimal pockets and external storage options. The cinch top closure also takes some getting used to (imagine a simple stuff sack) and does not completely protect from the elements. We loved this pack for short trips and light travel, plus its price tag is approachable, which is an added plus.
Read review: Ultralight Adventure Equipment CDT
Best for Exceptional Durability
Hyperlite Mountain Gear 3400 Porter 55
Missions in the mountains require packs that can handle two main things. First, the pack must be able to carry heavy loads. Second, it must be burly, which means it needs to offer protection from abrasions, and keep its contents safe from rain and snow. The Hyperlite Mountain Gear 3400 Porter 55 does all of these things with style. It's simple and sleek, with a roll-top closure and lots of external lashing options. Its side straps can accommodate skis, boots, tent poles, or ropes, while its small waist belt pockets can hold snacks, phones, and sunscreen. We liked the size of this pack, as it is a bit more versatile than some of its larger siblings from Hyperlite. Its Dyneema construction makes it one of the most durable and water-resistant packs we've tested.
Unfortunately, all of this comes at a cost. Hyperlite packs are some of the most expensive out there. You'll want to be sure this is the tool you need before throwing down for the Porter. Also, if you're into pockets and features and bells and whistles, this pack may be a bit disappointing.
Read review: Hyperlite Mountain Gear 3400 Porter 55
Why You Should Trust Us
Jane Jackson and Brandon Lampley spearheaded this review, bringing to the table a wealth of related experience. Two hundred+ days a year, you can find Jane outside using and testing gear. With years spent working and playing in the Yosemite backcountry, the Tetons, and the Wind River Range, as well as trips taken to the Alaska Range, the Himalaya, and Patagonia, Jane has spent plenty of time under the burden of a heavy pack. Brandon has hiked both the Pacific Crest Trail and Appalachian Trail, essentially back-to-back, with only four months off in between. He also has first ascents to his name in the Indian Himalaya and has summited Denali and Ama Dablam.
Our testing protocol consisted of both lab testing and trail miles. We made sure to independently test weight and volume measurements, as manufacturers have been known, at times, to fudge these numbers. We also took it a step further and scored packs based on their weight per unit volume, which allows us to compare models of different volumes fairly. On-trail testing included trips such as 260 winter miles on the AT and 40 miles in the Black Rock Canyons Wilderness in Colorado. Additionally, 15 and 30-pound test weights were used for shorter test laps for more direct comparison.
Related: How We Tested Ultralight Backpacks
Analysis and Test Results
Out with the old, in with the new. In this case, the new means a sleek ultralight backpacking pack to replace that old full-frame monster of a pack that's collecting dust in your garage. The competitors we evaluate here include the best and most versatile packs for lightweight and ultralight three-season backpacking, as well as a couple more specialized models for specific uses. The top models are all great choices for thru-hiking trips that last for months and shorter trips as well; expert backpackers will also find these packs just large enough for wintertime adventures.
We often trade off one thing for another when making an outdoor gear purchase, and no one understands trade-offs better than an UL enthusiast. We spend probably too much time "weighing" our options. To bring a slightly thicker sleeping pad means foregoing powdered milk in the coffee…decisions, decisions. Anyway, back to packs — the weight savings that you can achieve often comes at the expense of something else. For example, the Granite Gear Virga 2 was one of the lightest options (10 g/L) but was also one of the least comfortable to carry a lot of gear with. If you are looking for a good deal on a pack, but don't want to trade-off too much on the performance end, check out the Osprey Exos 48, our Best Buy winner. The Exos provides ample support and weight a bit more than other packs in this fleet, so consider the Granite Gear Virga 2 for an incredibly light and inexpensive model.
Weight-to-volume ratio is a measure we use here to compare packs and luggage of differing volumes. This heavily-weighted (no pun intended!) metric gets straight to the point; how much does this pack weigh relative to the volume it carries? Two sets of data, generated by our lab measurements, comprise this metric. First, we measured the weight of each model on our digital scale. Then, we weighed each pack with all modular components in place. Next, we examined each for a frame, waist belt, or other pockets that can be easily removed to pare the weight down for light loads. We then stripped these features off of each pack and weighed them again.
The most detailed lab testing with these products is our independent measurement of pack volume; since nominal volume measurements from manufacturers are difficult to compare, we decided to perform our test. Although an ASTM standard exists for measuring pack volume and many pack manufacturers perform ASTM testing, some report the capacity of only the main pack as the nominal measurement, while others include pockets. The ASTM test doesn't provide for measuring external pocket volume, which is significant for these packs. In our experiments, we measured the volume of the main pack, the main exterior pockets, and the lid (when present).
The weight-to-volume ratio is the most significant contributor to total scores, accounting for 35 percent. The Gossamer Gear Mariposa, the Granite Gear Virga 2, and ZPacks Arc Blast 55 earned the best scores; these are three of the lightest packs we tested and forego many of the features that are common on other models. By combining an incredible weight-to-volume ratio with a surprising level of carrying comfort, the Arc Blast wins our award for ultralight enthusiasts.
The ULA Circuit and ULA CDT earned the next best scores for weight-to-volume ratio, and they each measured a tiny bit better than the middle of the field with all their modular components in use. Both were also top performers when we compared "stripped weight" to "stripped volume." We were especially impressed by the ULA Circuit, which has a larger carrying capacity than the CDT. Unlike the Granite Gear Virga 2 or the ZPacks Arc Blast, both of these are fully-featured with hip belt pockets and can carry heavier loads in more comfort.
Of course, we all want an ultralight pack to be featherlight, but it must carry our load comfortably to be worth it. For each of these packs, we judged load-carrying comfort for two loads: 15 lbs and 30 lbs. We then averaged each pack's performance in both categories to generate our carrying comfort score. Fifteen pounds is a perfect comparison weight for ultralight hikers on a short trip, while thirty pounds is a fair comparison weight for lightweight hikers on shorter trips, ultralight hikers carrying a week's worth of food, or for those brave enough to travel in the winter. While some packs are capable of being stripped of their frame and waist belt, our evaluation of "great, good, or poor" for carrying 15 lbs and 30 lbs is with the frame and waist belt in use. We would recommend stripping down a pack completely when carrying 12 pounds (or less) total weight.
The Gossamer Gear Mariposa, Gossamer Gear Gorilla, and the ULA Ohm 2.0 earned our highest scores in this category (for carrying both 15 and 30-pound loads). These three packs are the easiest to strip of their frame and waist belts if and when you want to take 12 pounds or less. At this low weight, we feel frames, and even waist belts are not necessary.
Also notable in this metric are the next highest scorers. The Osprey Exos 48 carries 30 pounds more comfortably than any other we tested, but we found the tensioned frame a bit "turtle shell-like" for much lighter loads, meaning that the pack felt like it hovered awkwardly away from our back without weight. Other slightly heavier models, like those from Gossamer Gear, scored highly in the comfort metric due to their ample padding and suspension systems. The Gossamer Gear packs, in general, were able to carry both light loads and heavy loads comfortably.
- Best for 10-20 lb loads: Top Pick for Ultralight Enthusiasts: ZPacks Arc Blast 55
- Best for 15-25 lb loads: Editors' Choice: Gossamer Gear Mariposa
- Best for 20-35 lb loads: Best Buy: Osprey Exos 48
Manufacturers constantly seek to find the right balance of features for ultralight backpacks. Eliminating most creates a very light pack, but including the right features can greatly increase comfort, versatility, and ease of use. Some of the lighter full-sized packs we tested, like the ZPacks Arc Blast and Granite Gear Virga 2, earned top scores in our weight-to-volume ratio metric. However, this means that they are virtually glorified stuff-sacks with shoulder straps in terms of features (a.k.a. minimalist). By looking at their total scores, one can see trade-offs required to be the lightest of the bunch. This means reduced load-carrying comfort at heavier weights and reduced ease of use as a direct consequence of eliminating features.
Many of the newer packs we have added have a more balanced combination of weight, features, and comfort. Packs like the Gossamer Gear Murmur, the ULA CDT, and the Hyperlite Mountain Gear 3400 Southwest 55 all have a similar feature set including a roll-top closure and three external shove-it pockets on the outside. Manufacturers seem to be trending in this direction, so consider that when looking at new packs, as lids are seemingly becoming a thing of the past.
We provide a thorough description of each pack's features not covered elsewhere. When covering big miles on the trail, features like easily accessible side pockets for your water bottles, waist belt pockets for snacks, and a convenient place to keep maps handy are a huge benefit. This is also where we detail how each pack accommodates a hydration bladder and just how much stuff you can stow in the exterior pockets.
The Osprey Exos 48 incorporates so many features and is head and shoulders above the rest. While most manufacturers pick and choose which elements they think are the most useful, Osprey provides nearly every storage, lashing, and compression feature you can imagine. This is super convenient but contributes to the pack's relatively heavier weight.
The Gossamer Gear Mariposa also earned top scores in this category with its well-placed side pockets, over-the-top closure mechanism, and large mesh back pocket. Additionally, the ULA Ohm 2.0 received high scores in this metric, though the Gossamer Gear packs both have a large external back pocket, which the OHM 2.0 lacks. We love how much you can stuff in the Gossamer Gear pack pockets compared to the small volume of the Ohm's exterior pocket.
While our carrying comfort metric is focused on how well each pack can carry either 15 or 30 pounds in its full configuration, our adaptability metric focuses on other considerations when you may want to scale your pack up or down in carrying capacity. While on a thru-hike or a week-long adventure in the backcountry, your total bulk and weight will fluctuate up and down. You'll encounter re-supplies and weekend trips where you'll sometimes need to carry a substantial load, but other times you may carry less. A pack whose design allows the frame and waist belt to be easily removed for very light loads is more adaptable.
While many of our testers have several packs suited for varying loads, a highly adaptable contender is critical when you seek one backpack to do it all. Packs can receive high scores in this metric when they have an easy to remove frame or simple design. These features allow it to carry minimal weight, or to be easily packed with a massive load. The pack's overall design is versatile, too; we found it served its purpose as a lightweight model and was a fully functional pack for backpacking.
While stripping the pack down is an excellent feature for light loads, a kit that allows you to strap bulky but light items to the outside is a bonus when you need to carry big loads. Each of these competitors has multiple ways to add things, like a closed-cell foam pad, to the outside. While in general, we are not a big fan of lids for ultralight packs, they do create one key advantage: the ability to carry bulky items on top of the main compartment secured under the adjustable lid. The Osprey Exos 48 and the Hyperlite Mountain Gear 3400 Southwest both earned a top adaptability score because of their ability to carry heavy loads well with tons of external lashing options. The Hyperlite pack also has a very tall roll top, similar to the one found on the ULA Circuit, that provides a great place to store extra bulky items when a significant food resupply occupies the main pack.
Our adaptability score also considers ease of use with a bear canister. This will be irrelevant to some, but bear canisters are required by regulation on some portions of the PCT and AT. The BearVault BV500 is perhaps the most common bear canister used by weight-conscious hikers in areas where bearproof food storage is required in the backcountry. We loaded each pack up with a standard three-season kit and five days of food in the BV500 to see how well it fits inside and how much room is left over for the rest of your stuff. If you regularly carry a bear canister of this size, the Gossamer Gear Mariposa is compatible with this can.
How durable can a sub-two-pound backpack be? The answer is that most are surprisingly durable. That said, many of these packs require a little more care and attention than load monsters that weigh five or six pounds and use much heavier fabrics and frames. If you plan to carry more than 30 pounds most of the time, the packs in our backpacking review may serve you better. So how durable should an ultralight backpack be? As a baseline, to achieve an above-average score, we estimated that a pack must last for a least one thru-hike of a trail like the PCT or Appalachian Trail. The best of these packs will see you through many thousands of trail miles!
Many factors go into our rating for durability, which contributes 10% of the total scores. First and foremost, we consider the types of fabric used for the main body of the pack and the exterior pockets. All of these areas are subject to abrasion, especially the pockets (if you tend to stuff a lot into them). There are always trade-offs in design; for example, incredibly light main pack fabrics are less durable than robust 200 Denier nylon ripstop fabrics.
Additionally, the stretchy exterior pocket fabrics that we love for function tend to be more prone to snagging on tree limbs or abrading on rock (in comparison to non-stretchy pockets). Unfortunately, it seems that you can't have it all. In our experience, a stretchy main exterior pocket with durable side pockets is the best compromise. This type of design is found on the award-winning Gossamer Gear Mariposa. When it comes to materials, the Gossamer Gear Murmur is made of the most delicate we've seen in this review, and that should be considered when thinking about this product.
While it is the case that you'll need to treat your pack nicely (it is your home on your back!), we also take into consideration whether sitting on it while it is loaded or rough handling in the back of your van or truck could damage the frame. To this end, we think that if you are focused on durability or if you are known to be rough on your gear, you should choose a pack with an aluminum frame versus carbon fiber. The rugged aluminum frame is one of the many small factors that lead us to prefer both of the Gossamer Gear packs to the two ULA packs. The carbon rod frame found in the ULA Ohm 2.0 and the ULA Circuit is significantly more fragile. Out of our top scorers, the Mariposa is one model we felt comfortable sitting on without the worry of breaking something.
A rain cover for your backpack has long been one of the key accessories to ensure your ultralight backpacking kit stays dry through rainstorms. The Gregory Octal's UL Raincover is a reliable and widely available choice, as are the covers from Sea to Summit. That said, if you plan to travel in places with notoriously bad weather, like Patagonia, for example, it may not be a bad idea to consider investing in a Hyperlite pack, which in our experience provided unparalleled protection from the elements, even on the wettest days.
Waterproof roll-top style dry bags or Cuben stuff sacks are an excellent choice for both organization and moisture protection inside your backpack. Sea to Summit's ultralight Sil-Nylon bag is also an ideal choice. For those seeking to shave off the grams, Hyperlite Mountain Gear, ZPacks, and several other ultralight manufacturers produce a large variety of Cuben fiber storage and stuff sacks.
Lining your backpack with a contractor's plastic garbage bag, or better yet a trash compactor bag, has long been a great option to ensure your kit stays dry during long rainy days on the trail. While one of these should last you for a week or more with a little care, you would replace it often while thru-hiking. Cuben fiber pack liners are the state-of-the-art in super light and durable waterproof pack liners. The models available from ZPacks are the best we've seen.
If you're interested in cutting weight even further, you can use a sleeping pad as a back pad in a frameless backpack.
Hopefully, this review shows that there are endless benefits to going ultralight. We took our time to assess the performance of these packs both in the lab and on the trails. The goal is to find the sweet spot between dropping weight without losing the features that make your trip fun and comfortable. We've also tested tons of other packs in our backpacking, mountaineering, and daypack reviews, so make sure to identify your goals and find the pack that truly suits your needs.
— Jane Jackson & Brandon Lampley