The Best Ultralight Backpack Review
For many backpackers and thru-hikers, an ultralight backpack is a must-have. So, our review team set out to find the best. We purchased nine of the most popular and highly rated ultralight packs and tested them side-by-side for six months. From the Colorado Trail and the summits of 14ers, to a 250-mile wintertime adventure on the Appalachian Trail, we logged the miles to find the best. In addition to hundreds of days of testing in the wilderness, we incorporated the feedback of experienced thru-hikers and performed a significant amount of laboratory testing. Whether you're gearing up for a six-month thru-hike or fine-tuning your kit for ultralight weekend backpacking, we've got you covered.
Read the full review below >
Test Results and Ratings
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Analysis and Award Winners
Updated March 2017
We added performance graphs and charts from our test period analyses to help show how these products performed in each metric. Also, the Gear Gorilla and Arc Blast 52 products have been updated by their manufacturers. In the individual reviews, we detailed the changes made to these products in order to compare the latest versions.
Best Overall Ultralight Backpack
Gossamer Gear Gorilla
While we tested many excellent packs in this ultralight backpack review, one uber-performer came out on top in our scoring: the Gossamer Gear Gorilla. It is functional and comfortable when carrying very light loads, carries 20 to 30 pounds equally well, and is more adaptable and durable than most of the other contenders. With our favorite kind of pockets in just the right places and a burly but light aluminum frame that is easily removable for light loads, the Gorilla is hands-down our favorite ultralight backpack if we could only have one pack for all of our lightweight backpacking and thru-hiking adventures. Gossamer has confirmed with us that they have updated this pack since we reviewed it, redesigning the hip belt and aluminum frame. More details on the updates are in the individual review.
Carries light and medium loads well
Perfect feature set
More durable than most
A little small for a bear canister
Read full review: Gossamer Gear Gorilla
Best Bang for the Buck
Osprey Exos 48
The Osprey Exos 48 is the most affordable pack in this review that landed among our top five scoring products. It carries very light loads reasonably well, has the most refined and utilitarian set of features, and truly delivers when you want to carry overall loads of 20 pounds or more. Anytime we headed out carrying 30 pounds or a little more, it was difficult to not choose the Exos it just carries relatively heavy loads better than others over long miles. As an added benefit, this Osprey pack is widely available from online sources and bricks and mortar retailers, which isn't the case with our other two award winners. If you want to buy a pack today and head out on a lightweight backpacking adventure next weekend, the Exos 48 is your best bet.
Perfect for medium loads
Most complete set of features
Many external storage and lashing options
Not as durable as others
Read full review: Osprey Exos 48
Top Pick for Ultralight Enthusiasts
ZPacks Arc Blast 52
The ZPacks Arc Blast 52 is the lightest backpack we tested that can comfortably carry 20 to 30 pounds when you need it to, but really excels when carrying 10 to 20 pounds. Weighing in at 21 ounces, it is a half pound lighter than any of the other top scoring packs in this review. Built with a hybrid Cuben fiber material and carbon frame components, this is the pack several of our thru-hikers testers chose for multi-month hikes when every ounces matters. If you are an experienced ultralight hiker seeking to spare another half pound or more from your Big Four base weight, the Arc Blast receives our highest recommendation. This ZPacks has received some minor updates since our review was published, including changes to the volume (more of it), frame, and belt, sternum, and top strap buckles. We have detailed these changes in the individual review of this product.
Lightest pack with a frame
Good external storage
No hip belt pockets (available add on)
Read full review: ZPacks Arc Blast 52
Honorable Mention for Multi-day Trail Running: Ultimate Direction Fastpack 30
The Ultimate Direction Fastpack 30 is the smallest pack we tested in this review, and the only purposely designed for multi-day trail running adventures. We carried up to 15 lbs in it during a two-day trip and stayed relatively comfortable. If you want an ultralight running pack with capacity for multi-day trips, it is perfect.
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Analysis and Test Results
The nine backpacks 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 five highest scoring 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. Our award winners distinguished themselves as the best overall, the best bang for your buck, and the best for experts who travel with very light loads. Read on to learn more about the types of packs we tested, and to find the top performers in each of our evaluation metrics.
The individual reviews for each model detail our laboratory and field test findings and closely compares the pack to its closest competitors. These individual reviews also cover each product's most important features and provide sizing information (plus other options). This review is the third in our series of Ultralight Reviews: check the Best Ultralight Sleeping Bags and Best Ultralight Tent Shelters. Combined with our review of the Best Sleeping Pads, these three ultralight reviews cover the strategy and tactics for dialing your pack weight down for a thru-hike or light weekend adventures. The related Buying Advice articles provide the guidance you need to select the Big Four components of an ultralight backpacking kit, whether you're seeking an 8 lb or 14 lb base weight.
One of the most important factors to consider when choosing a backpack is the weight of the load that you'll most commonly be carrying. As you read this review, you'll notice that factors like carrying comfort and adaptability are closely tied to how much weight you plan to travel with. This is affected by the frame (as we discuss just below) and the general pack construction. If you plan to carry more than 30 lbs most of the time, the packs in our Backpacking Backpack review will serve you better.
Types of Ultralight Backpacks
In this review, we focused on packs that are just big enough for most ultralight hikers to be out for a week between re-supplies. Our lead tester found that eight of these nine packs fit his winter kit plus food and fuel for a 5 day wintertime chunk of the Appalachian Trail. By our laboratory volume measurements, we found most of these packs carry very close to 50 liters between the main bag and the exterior pockets. The Ultimate Direction Fastpack 30 and the JanSport Katahdin 40 are the exceptions, measuring significantly smaller in carrying volume. In the following paragraphs, we break down the packs in our review by frame type.
Simple frames come in a couple of varieties, and for this grouping we define a simple frame as a frame that is not arced and held in tension to create airspace at your back. At the simplest end of the frame spectrum is the throwback design of the Hyperlite Mountain Gear Windrider, with two independent flat aluminum stays placed vertically in the back panel. More advanced are the upside down U shaped frames of the Editors' Choice Gossamer Gear Gorilla and the ULA Ohm 2.0, in tubular aluminum and carbon/Delrin respectively.
Simple frames prevent torso collapse in the pack body, and help load transfer to the hip belt. The models we tested with simple frames are:
Tensioned Air Frame
Several of the packs we tested incorporate a tensioned frame that is not only designed to carry loads well, but creates space at your back for air flow. Many hikers that tend to sweat a lot or whose adventures are primarily in warm to hot seasons of the year prefer a pack with ventilation between a potentially sweaty back and the backpack. The Best Buy Osprey Exos 48 and Top Pick ZPacks Arc Blast 52 both use light tensioned frames.
In addition to usually carrying heavier loads more comfortably, a tensioned frame creates ventilated airspace between your back and your pack's body. The models we tested with tensioned frames are:
For very light loads, many enthusiasts carry a smaller pack than those we tested here. With overall loads less than 15 pounds, a frame becomes less important for carrying comfort. But in this review, we focused on packs capable of carrying loads up to 30 pounds when necessary. The only frameless pack we tested, the Granite Gear Virga 2, is a throwback to an era when many if not most backpackers carried a closed cell foam sleeping pad. The Virga is designed to function best when a rolled closed cell foam pad is placed inside forming a barrel-like frame.
The Granite Gear Virga 2 is a large volume frameless pack that performs best when a rolled closed cell foam pad is placed inside forming a "barrel frame."
Best Uses for Ultralight Backpacks
Seems fairly simple, right? You'll find these ultralight packs perfect for you if your backpacking adventures are focused more on covering the miles in unburdened comfort, and focused less on carrying lots of kit and luxuries for camping. In addition to the main compartment, lots of external storage provides quick access to food and important clothing layers while on the go.
To us here at OutdoorGearLab, ultralight backpacking is primarily defined by minimalism; carrying just the right amount of the best gear to stay safe, warm, and happy while covering our trail miles. Most experienced thru-hikers and ultralight enthusiasts that we know have developed three-season backpacking kits with a base weight of 7 to 11 pounds. At the lighter end of this spectrum, many forgo a stove for cooking. At the heavier end are folks that cook some of their meals, carry a few extra warm clothing layers, and have a few luxury items like a camera or a book or two. Add in consumables and pack weights are often in the high teens or low 20s. When our lead tester packed for a wintertime 250 mile chunk of the Appalachian Trail, his base weight came in at 13 pounds.
We strongly feel the four top-scoring packs we tested (all of which have minimal frames for support) are the best choice for most ultralight backpackers for three-season use. The best of these packs also provide the capacity and load carrying ability tackle cold, winter conditions. For folks with heavier base weights or scaling up for winter, we recommend the fully-featured Gossamer Gear Gorilla. On the other end of the spectrum, the ZPacks Arc Blast 52 is our go-to pack when total weight rarely gets above the teens.
As we define lightweight backpacking, base weight is between 13 and 20 pounds. Many novice backpackers seeking to reduce their loads to the lightest possible weight without compromising their safety or spending a few thousand dollars on equipment fall into this realm. It is quite common for relatively new folks gearing up for a thru-hike of a long trail to develop a kit that weighs in around 13 to 15 pounds. You can pull this off quite affordably. With a base weight in this range, you'll commonly carry 25 pounds once you add in consumables. An ultralight pack with a simple frame or tensioned frame for support is the perfect choice for you. The Gossamer Gear Gorilla, ULA Ohm 2.0, and Osprey Exos 48 handle these loads really well.
Thru-hiking, or tackling one of the many popular long-distance trails like the Pacific Crest Trail or Appalachian Trail, is really no different than ultralight and lightweight backpacking described above. With the exception that the time spent carrying your house and home on your back is measured in months rather than days or weeks. While paring down your kit to the lightest safe weight for you is compelling, so is the ability to carry a substantial load when it is necessary. In sections of the Mojave desert in Southern California, PCT hikers need to carry six or more liters of water on a few days. On long trails, it is also not uncommon to carry a week's food or more while hiking through some of the more remote terrain. The Gossamer Gear Gorilla, ULA Ohm 2.0, and Osprey Exos 48 are all excellent choices for thru-hikers because they can comfortably handle the heavier loads that are sometimes necessary. The ZPacks Arc Blast 52 is perfect for folks moving fast enough to avoid the heavier loads.
Criteria for Evaluation
The rating table below shows where each ultralight pack in our review ranked in cumulative score.
Weight-to-volume ratio is a measure we use here at OutdoorGearLab to compare packs and luggage of differing volumes. This 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. First, we weighed each pack with all modular components in place. Next, we examined each for 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 each pack and weighed them again.
The most detailed lab testing with these products was our independent measurement of pack volume - since nominal volume measurements from manufacturers are difficult to compare, we decided to perform our own test. Although an ASTM standard exists for measuring pack volume and many pack manufacturers perform ASTM testing, some report the volume 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 on these packs. In our tests, we measured the volume of the main pack, the main exterior pockets, and the lid (when present).
To provide an example, the Gossamer Gear Gorilla is described nominally as a 38 liter pack and the ZPacks Arc Blast as 52 liters. However, we found these two packs nearly identical in volume, both when performing our laboratory volume testing with ping pong balls and when packing in the exact same kit for a five-day wintertime trip on the Appalachian Trail.
Weight-to-Volume Ratio is the largest contributor to total scores at 35%. The Granite Gear Virga and ZPacks Arc Blast earned the best scores. These are the two lightest packs we tested and forgo many of the features common on other models. Neither has hip belt pockets and the Virga doesn't have any sort of frame. Thanks to its stand-out weight-to-volume ratio (and its carrying comfort), the Arc Blast won our Top Pick Award for Ultralight Enthusiasts.
The Gossamer Gear Gorilla and ULA Ohm 2.0 earned the next best scores for weight-to-volume ratio. Both measured just better than the middle of the field with all their modular components in use and both were top performers when we compared "Stripped Weight" to "Stripped Volume." Unlike the two minimalist packs above, 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 feather light, 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 and thirty pounds is a fair comparison weight for lightweight hikers on shorter trips or ultralight hikers carrying a week's food or traveling in the winter. While some packs can be 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 feel you'd want to strip down a pack completely for carrying 12 lbs or less total weight.
Only two of the ultralight backpacks we evaluated earned our "Great" score for carrying both 15 and 30 lbs: the Gossamer Gear Gorilla and the ULA Ohm 2.0; as a result, these packs earned our highest overall scores. In addition, these two packs are the easiest to strip of frame and waist belt if and when you want to carry 12 lbs or less. At this low weight, we feel frames and even waist belts provide little benefit.
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. The Arc Blast 52 also earned a high score. It carries 15 to 25 lbs as comfortably as any other pack, but we found 30 lbs a bit too much.
To simplify our findings for load carrying comfort even further, we feel each of our three award winners fits a good niche as far as load carrying comfort goes:
Manufacturers constantly seek to find the right balance of features for ultralight backpacks. Eliminating most creates a very light pack, but including the right ones can greatly increase comfort, versatility, and ease of use. The lightest two packs we tested, the Arc Blast and Virga 2, both earned top scores in our weight-to-volume ratio metric, but their total scores reflect the trade-offs required to be the lightest: reduced load carrying comfort at heavier weights and reduced ease of use as a direct consequence of eliminating features.
In our individual reviews, 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, it's really head and shoulders above the rest. While most manufacturers pick and choose which features 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 Gorilla and the ULA Ohm 2.0 earned the next highest scores for features. We think they include the most useful ones. The primary differentiating feature is the large and very stretchy exterior pocket on the Gorilla. We love how much you can stuff in there 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 between re-supplies and for weekend trips sometimes you'll need to carry a substantial load, but other times you may carry very little. 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 pack is awesome when you seek one pack to do it all. The Gorilla and the Ohm 2.0 earned high scores in adaptability largely because they are the two packs where removing the waist belt and frame for light loads is a simple process.
While stripping the pack down is a great feature for light loads, a pack that allows you to strap bulky but light items to the outside is awesome when you need to carry big loads. Each of these packs has multiple ways to add bulky items like a closed cell foam pad to the outside. And 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 Exos 48 earned a top adaptability score because of its ability to carry heavy loads well with myriad external storage and lashing options. The Hyperlite Mountain Gear Windrider 3400 also earned a top score: its two aluminum frame stays can be removed (though not the waist belt), and the external lash system and very tall roll top provide options for bulky but light gear when a big 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 bear-proof food storage is required in the backcountry. We loaded each pack up with a common 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, only the Windrider 3400 easily accommodates it (this pack earned a "Good" rating) among our pool of competitors. Our three award winners we rated 'Just OK' for use with the BV500; it fits inside, but the smaller diameter of these packs makes packing around it a challenge. See each packs individual review, where in the Other Versions section we point out their cousins with a bit more capacity.
How durable can a sub-two-pound backpack be? The answer is that most are surprisingly quite durable. That said, many of these packs require a little more care and attention than load monsters that weigh five or six lbs and use much heavier fabrics and frames. If you plan to carry more than 30 lbs most of the time, the packs in our backpacking backpack review will serve you better. So how durable SHOULD an ultralight backpack be? As a baseline, to achieve an above average score, we think 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!
A number of 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 very light main pack fabrics are less durable than robust 200 Denier nylon ripstop fabrics. The Mammut Creon Light 45, a pack designed more for off-trail, alpine scrambling, is made of notably durable fabric.
The main fabric of the ULA Ohm 2.0 is likely the most durable over the long haul, but its carbon frame is a liability for rough handling. Our durability rating also considers frame durability and pocket 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. We think that a stretchy main exterior pocket with durable side pockets is the best compromise. This is the design choice made by Gossamer Gear for the Editors' Choice winning Gorilla.
And 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 the pack while it is loaded or rough handling in the back of your van or truck could break 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 the Gossamer Gear Gorilla over the ULA Ohm 2.0. The Ohm's carbon rod frame is significantly more fragile. Out of our top scorers, the Gorilla and Windrider are the two models we feel comfortable sitting on without worry of breaking something.
A rain cover for your backpack has long been one of the key accessories to ensure your backpacking kit stays dry through rainstorms. The Osprey UL Raincover is a dependable and widely available choice, as are the covers from Sea to Summit.
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 bags are an excellent choice. For those seeking to really 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.
An ultralight backpack is just one of the many products featured in our Dream Backpacking Gear List. Check it out for all of our "dream" backpacking gear and clothing in one spot!
Ask an Expert: Chris Solinsky
What was your first extending backpacking trip and generally how much stuff did you carry? How heavy was your pack?
My first extended backpacking experience was in fact my thru-hike of the Appalachian Trail. I had never done more than an overnight in the woods before. My pack for the hike was a Gregory Baltoro 65. The pack itself weighed 6.5 lbs and I started the hike April Fool's day 2007 with a pack weight of 62 lbs. I knew nothing about backpacking and received a rude awakening. At Neels Gap I mailed home something like 18 lbs of uselessness and continued to learn what I didn't need as the hike went on. I kept the pack for the whole hike despite its weight. By the end of the hike I had managed to get down to carrying about 30-35 lbs with food and water on average.
What backpacks have you used on your subsequent thru-hikes?
On my 2010 PCT thru-hike I carried a Gregory Z55. It was 3 lbs lighter than my last pack and my base weight was down to about 18-20 lbs starting out. I thought I was doing pretty well.
For my CDT thru-hike I carried a Mountain Hardware Fluid 48, which was 3.5 lbs and a clearance item. After my Z55 experience I was looking for durability over anything else. I had heard good things about this company's build quality and the price was right at just over a hundred dollars clearance. It held up well through the hike and is still going after a few trips abroad.
Share with us one of your favorite sections of the Triple Crown trails.
One of my favorite sections of trail was the Goat Rocks Wilderness. I remember waking up to a dozen elk bugling right on trail; seeing two herds of mountains goats, one of which crossed the trail right on front of me; and sitting atop a ridge when a boulder let go and shot through a snow field kicking up a huge rooster tail.
What do you believe are the most important considerations when choosing an ultralight backpack?
When I'm considering a pack to use, after the appropriate volume, my primary concern is durability. I tend to be rough on my gear. If needing to set my pack down a certain way to avoid puncturing it is a condition of saving a few ounces, the pack is worthless to me. I would also sacrifice weight for load carrying comfort. I prefer a pack with more capacity than I typically need and I like to be able to carry a bit more weight comfortably. During a thru-hike, carrying some extra cold drinks or fresh food the first day out of town is a typical priority of mine.
You might also want to check out this video on how to use sleeping pad as a back pad in an ultralight backpack.
— Brandon Lampley
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