13 Best Ultralight Backpacks for Thru-Hiking in 2021

A comprehensive guide to the best ultralight backpacking packs. Tested and written by Appalachian Trail and Pacific Crest thru-hikers.

by Chris Cage
Updated on Apr 13th, 2021

In this post, we review twelve of the best ultralight backpacks on the market today. Your pack is one of the “big three” areas you can save weight on. In this guide, you'll learn what to look for when buying a thru-hiking pack and essential tips such as how to organize your gear inside your backpack. Let's jump right in with a little bit of background history.

The Evolution of Backpacking Packs

Ultralight backpacking was once a small subset of the backpacking community as a whole. The ultralight ethos has now reached the mainstream market and manufacturers are adapting their products to meet the increasing demand for lighter gear.

When it comes to backpack selection, we've seen the disappearance of packs with too many features that add weight such as certain types of compartmentalized storage, expanded capacity, traditional (heavier) fabrics, or a traditional frame. 

ultralight vs regular hiking backpack

A. From External Frame to No Frame at All: In my Boy Scout days, many backpacks had thick, rectangular, external metal frames. Fortunately, those have nearly gone extinct and have been replaced by thin internal metal frames that outline the contours of your body. As technology has helped lighten gear more and more, the need for support in a backpacking frame has decreased. Many packs use thin plastic sheets or foam pads... or no frames at all... AND work great!

B. Lighter Materials:
Lighter materials like Dyneema® or other laminate fabrics such as X-Pac have come into mainstream use. The materials offer advantages like lightweight durability or nearly water-proof compartments that replace outdated storage spaces such as a pack brain/lid or separate sleeping bag compartment.

C. Minimalist Design:
A lot of the bells and whistles that used to come standard with backpacking backpacks have started to disappear. Zippers are gone. Some packs have been designed to reduce straps or replace straps with cordage where appropriate. Other models ditch the hip belt or reduce it to a nylon strap free from padding or pouches. In fact, it’s become popular enough that the backpacking world has seen a resurgence in the use and popularity of fanny packs (aka hip-packs).

Hyperlite Mountain Gear WindriderHyperlite Mountain Gear Windrider

Ultralight Requirements


A "true" ultralight backpacking pack will weigh under 2 lbs.

You don't want anything above 3 lbs. There is a clear cutoff on style and design for packs above 3 lbs. They have lot more padding and more framework.

These extras are only worth it if your are carrying an extremely heavy load (anything above 45 lbs). This may apply to you if you need to carry all your family's gear, for instance.

Otherwise, even with a week's worth of food, your load should probably never exceed 35 lbs - ideally more like 20 or 25 lbs.

Minimalist hiking backpackShoulder pockets with ample storage (Six Moon Design Minimalist)


The larger your pack, the more unnecessary stuff you'll be inclined to pack and the heavier the load you'll end up carrying. Choosing a smaller pack can be somewhat advantageous because it forces you to prioritize your item selection to be lighter and more compact.

“If you have it, you will fill it.” - Wise Man

I recommend a carrying capacity of no less than 40 liters and no more than 65 liters. 50 to 55 liters is a good middle ground. Mine was 58 liters on the Appalachian Trail and I would have liked just a tiny bit less space.

45 liters would be my ideal volume. I’ll admit, though, it can be a challenge to fit everything into 45 liters, especially with any extra winter gear and several days of food.

Note many manufacturers include the external pockets as part of their measured carrying capacity. Keep in mind you will pack items on the outside of your pack (water bottle, rain shell, damp clothes, etc).

Regular (far left), Lightweight (mid left), Ultralight (mid right), Hyperlight (far right)


Cuben fiber and nylon are the most common types of materials used for ultralight backpacks. Both are great for their intended function of protecting your gear. However, there are some differences to note.

  • Cuben Fiber (aka Dyneema): An ultralight, expensive, and abrasion-resistant blended synthetic fiber that’s nearly 100% waterproof and labeled as “the strongest fabric in the world.” It's lighter, stronger (won't rip as easily) and more waterproof than other options out there.

  • Silnylon: MUCH more affordable and potentially longer life (more abrasion and UV resistant).

  • Robic: A high tenacity ripstop nylon resilient to tears and abrasion. ROBIC nylon 6 is around 50% stronger than standard nylon. 

  • X Pac: Strong and lightweight, X Pac is a layered fabric made with a nylon face, an “X-Ply” polyester tear-resistant mesh membrane, and a waterproof film treated with a water-resistant coating. X Pac bags are incredibly rain resistant, withstanding up to 200 PSI. 

Granite Gear Crown2A thru-hiker's favorite (Granite Gear Crown2) 


Most long-distance backpacks are ‘top-loaders’ meaning you access your gear from an opening at the top of the bag. They are closed either by drawstring or roll top. Draw string is faster to open, roll top is a tighter seal.

Don't get a side loader. The zippers add additional weight. Proper organization will prevent you from needing to access all of your gear at any point in time. Keep it simple; keep it top-loading.

A "brain" is the head flap on the top of some packs. Provides quick access to small gear items that may not fit into the hip pockets. Sometimes it is removable and can be used as a day pack. I find them too floppy and frankly, unnecessary.

Roll top closure on the ULA Equipment CDT backpack


Models Weight Volume Price
Gossamer Gear Mariposa 2 lb 0.7 oz 60 L $260
ULA Equipment CDT 1 lb 8 oz 54 L $145
HMG 2400 & 3400 Windrider 2 lb 55 L $345
Osprey Levity 60 1 lb 14 oz 60 L $220
Granite Gear Crown2 2 lb 2 oz 60 L $200
Zpacks Arc Blast 1 lb 5 oz 55 L $325
Six Moon Design Swift X Backpack 2 lb 3 oz 45 L $270
Waymark Gear Co Thru 40 1 lb 7 oz 40 L $240
SWD Long Haul 50 1 lb 9 oz 60 L $275
MLD Exodus 1 lb 57 L $195
Gregory Optic 48 2 lb 8 oz 48 L $190
Mountainsmith Zerk 40 1 lb 12 oz 35 L $220
Atom Packs Atom+ 1 lb 4.5 oz 35 L $308

Gossamer Gear - Mariposa

best ultralight backpacks - gossamer gear mariposa

Weight: 2 lb 0.7 oz

Capacity: 60 L

Price: $260 (with hipbelt)

Gossamer Gears' Mariposa is one of my favorite ultralight backpacks. It is a simple pack with a perfect amount of external pockets and loops. The Mariposa has a top loading flap that is super easy to buckle down and is adjustable for varying load capacities. The flap's zipper pouch makes small items, like your map or a snack that don't fit into the hip pockets, very accessible.

This pack's well-cushioned shoulder and hip pads make it feel like a resting pillow on your back. One of my favorite features is the removable back panel—great for an easy seat on a rough surface. Ah... and don't forget the awesomely airy front mesh pocket.

Overall, superb pack for ultralight thru-hiking.

Other popular models by Gossamer Gear: Silverback (50 L) | Gorilla (40L) |  Kumo (36L)

Available at Gossamer Gear

ULA Equipment - CDT

best ultralight backpacks ula equipment cdt

Weight: 1 lb 8 oz

Capacity: 54 L

Price: $145

For a backpack under 2 lbs AND under $150, the ULA-Equipment's CDT is a fantaaastic value. A very well-balanced pack—not too minimal, yet not too excessive. Similarly, 54 Liters is a great size for thru-hiking—not too small to carry a week-long food supply, yet not too bulky. This pack has a very simple and rather non-existent frame which makes it only ideal for light loads (under 20 lbs). Complete with spacious hip pockets, side water bottle pockets and a massive mesh front panel.

Instead of cuben fiber, ULA Equipment uses rip stop nylon. The nylon comes in a variety of fun colors—green, red and purple. Other ULA models are known for unique yellow water bottle holsters on the front shoulder straps for drinking while hiking. Its trekking pole holsters are also second to none.

I highly recommend checking out their other models like the larger and stronger-framed Circuit and the mid-weight Catalyst as well.

Available at ULA Equipment

HMG 2400 & 3400 - Windrider

best ultralight backpacks - HMG- 2400 Windrider

Weight: 2 lb

Capacity: 55 L

Price: $345

Hyperlite Mountain Gear is an ultralight icon and the 3400 Windrider backpack is one of the products that makes them so great. The high-tech Dyneema® material helps keep this pack at a flat 2 lbs. The material is so waterproof, you can usually get by without using a pack cover or liner at all.

The sleek design and minimalist style make it a true ultralight pack. I love how big the front mesh pouch is and how breathable the big holes are. Other features: a sternum strap whistle, removable aluminum frame 'stays', seam-sealed hip pockets and a top loading roll top enclosure.

For other sizes, check out their smaller 2400, larger 4400 and Southwest models. Also now available, the Junction from HMG delivers Dyneema Hardline side pockets for abrasion resistance and a center mesh pocket for breathability. It’s available in 2400 or 3400 sizes.

Available at Hyperlite Mountain Gear

Osprey - Levity 60

best ultralight backpacks - osprey levity 60

Weight: 1 lb 14 oz

Capacity: 60 L

Price: $220

Osprey Packs is the commercial leader of quality backpacking packs. They are the biggest brand on this list and make up the largest portion of AT and thru-hiking packs. They have a great warranty policy, a reasonable price tag, and prioritize comfort and support.

You would think this extra comfort puts them in a slightly heavier category—not the Levity 60. This new model seems more similar to the earlier Exos' models—minimalist and around 2 lbs. It does not have hip belt pockets and comes with a lower carrying capacity.

The signature concave metal frame is known for its' breathability and allowing air to flow in between your back. Note this frame sticks out from your back and, to me, can sometimes feel like a turtle shell.

See the smaller Levity 45 as well.

Available at REI

Granite Gear - Crown2

best ultralight backpacks - granite gear crown2 60

Weight: 2 lb 2 oz

Capacity: 60 L

Price: $200

This is the best bang for your buck backpack on the market.

Granite Gear made an awesome minimalist backpack with the Crown2 60. No extra pockets or frills. A single roll top main compartment complete with big exterior pouches and simple compression straps.

It does not get any more affordable than the Crown2 either. This comes with all of the features of any great thru-hiking pack—weighs near 2 lbs, has the ideal amount of pockets, adequate volume, extremely supportive frame and internal hydration sleeve. And, for all of you folks who want a brain, the Crown2 comes with a removable one.

Also check out the Granite Gear Virga 2, a 54 L frameless backpack that weighs in at a mere 1 lb and 3 oz.

Available at REI

Zpacks - Arc Blast

zpacks arc blast ultralight backpack

Weight: 1 lb 5 oz

Capacity: 55 L

Price: $325

The Zpacks Arc Blast is the Holy Grail of ultralight backpacks. It is by far the lightest framed pack on our list. Even with Dyneema fabric, it is still a mystery how Zpacks gets a 55 liter pack with a complete frame to weigh this little.

Similar to Osprey's Exos, the Arc Blast has a concave frame ideal for keeping your back as airy as possible. There are hip pockets available to attach for $25 extra.

Available at Zpacks

Six Moon Design Swift X Backpack

swift x ultralight backpack by six moon designs

Weight: 2 lb 3 oz

Capacity: 45 L

Price: $270

A fresh take on the 10-year classic “The Swift,” this frameless new and improved version has an adjustable torso length to fit any wearer's height. It’s equipped with a removable hip belt and an optional shoulder or vest harness strap system to ensure a close, comfortable fit. There’s also a removable water bladder and two hydration ports.

As for storage, there’s a lot. Think multiple pockets for gadgets, snacks, and gear of all sizes. There’s a 38 L, roll-top main storage bag and an additional 6 L in the extension collar, along with dual side pockets that can hold two 1 L size water bottles. The bag has additional zippered and cinch pockets in the hip belt, at the back of the bag, and along the shoulder straps.

Six Moon Designs also offers their 48 L UL Minimalist pack, a backpack with an optional frame, weighing in at just 1 lb 6 oz.

Available at Six Moon Designs

Waymark Gear Co - Thru 40

best ultralight backpacks - waymark gear co thru 40

Weight: 1 lb 7 oz

Capacity: 40 L

Price: $240

Waymark Gear Co taps into zen-like balance with the Thru, 40 bringing one of the best weight-to-durability options to ultralight hiking. It offers 40L of storage and no frame. It's perfect for comfortably carrying loads  up to about 27lbs.

If the lightweight durability doesn’t grab your attention, the options might. You can customize things like color, Lycra or mesh front pocket, and a removal 1” hip belt or a fully padded hip belt. Overall, this simple, well-built design offers customizable lightweight durability in a simple but stunning design.

Available at Waymark Gear Co

SWD - Long Haul 50

best ultralight backpacks - SWD Long Haul

Weight: 1 lb 9 oz

Capacity: 60 L

Price: $275

Superior Wilderness Designs is another cottage industry gear manufacturer launched after a PCT thru-hike. All gear is completely handmade in Michigan.

The Long Haul comes with 50L of internal volume along with 10L of external pack space. The suspension frame is comprised of 2 removable aluminum stays, enabling it to carry heavier 30 to 35 lb loads. S-shaped shoulder straps, trekking pole attachments, cushy hip belt and waterproof material make this pack a winner.

There are also countless fun color variations to choose from (main body, accent straps and bottom) as well as different customizable features (hipbelt, hydro port and internal hang loop).

Available at SWD

Mountain Laurel Designs - Exodus

best ultralight backpacks - mountain laurel designs exodus

Weight: 1 lb

Capacity: 57 L

Price: $195

Mountain Laurel Design's Exodus weighs a whopping 1 lb, as in less than half of the weight of other packs on this list. Why? Well, it is completely frameless and does not come with load lifters or hip pockets. If you have a hyper-light load though (20 ish lbs), this baby could be your ticket to becoming a fastpacking speed demon.

The Exodus is constructed from a high quality Dyneema and Silnylon fabric blend. Complete with full-sized pack features like trekking pole loops, airy pockets, compression straps and bungy attachments

It does not get any lighter than this. And for $195, it is extremely affordable. Also available in black/ grey.

Also check out MLD's Prophet and Cuben Fiber models.

Available at Mountain Laurel Designs

Gregory - Optic 48

best ultralight backpacks - gregory packs optic 48

Weight: 2 lb 8 oz

Capacity: 48 L

Price: $190

Gregory might be an old name in hiking packs but the old dog has new tricks with the Optic 48. The Optic has a ventilated suspension mesh for comfort and to wick moisture off your back. You can choose the brain-style storage top for the pack or ditch it for the included ultralight weather flap instead.

There are a ton of thoughtful details built into the pack showing the veteran craftsmanship from Gregory. From the ergonomic zipper pulls to the quick-stow system for sunglasses, the design makes each interaction with the bag pleasant and efficient.

Bonus: if you prefer pack covers over pack liners, the Optic comes with its own color-matched, perfect-fit pack cover.

Available at REI

Mountainsmith - Zerk 40

best ultralight backpacks - mountainsmith Zerk 40

Weight: 1 lb 12 oz

Capacity: 35 L

Price: $220

The Mountainsmith Zerk was co-designed over the course of over 2 years and 5,000 miles of testing by prolific outdoor personality The Real Hiking Viking.

This frameless pack carries comfortably due to the ultra-running inspired shoulder straps. Using the straps helps shift weight to the front of your body and balance the load, bumping up the level of comfort. The pack has a removable hip belt although it’s mostly there to help the pack hug your body rather than to provide support. You’ll gain flexibility with removable bear canister straps so you can strap on the canister for trips that require one or leave the straps at home when irrelevant. I’d love to see these straps become standard for pack design.

Lastly, the side pockets are conveniently oversized for your gear and have bonus pockets that can stow additional small items or snacks. It’s a design that affords balance and convenient storage in an ultralight form factor.

Available at Mountainsmith

Atom Packs - Atom+

best ultralight backpacks - atom

Weight: 1 lb 4.5 oz

Capacity: 35 L

Price: $308

Atom is a UK-based company that makes sleek ultralight backpacks designed with thru-hikers in mind. They're known to make highly customizable packs. For a small fee, hikers can choose their own size, color, features, fabrics—you name it.

The standard Atom+ is a 35L backpack with two large side pockets that provide an additional 5L of storage. It is built to sustain loads of up 30 lbs. If you plan on carrying heavier loads, check out Atom's Mo pack.

Compared to other packs on this list, we particularly appreciate the removable hipbelt and back panel. You can essentially adapt the pack's configuration to match your needs on any given hike. We also can't talk about the Atom+ without mentioning its coveted stretchy bottom pocket, ideal for storing trash or clothing you need to access on the go (eg. rain jacket). 

At $308, the Atom+ surely isn't the cheapest pack on our list, but it's a remarkable ultralight option nonetheless—especially if you live across the pond. Note that Atom ships to the US and Canada for a flat $30 fee. The lead times tend to be quite long though, so plan ahead. 

Available at Atom

More Packs to Check Out

Pa'Lante Packs V2

best ultralight backpacks - pa'lante

Weight: 1 lb 1 oz

Capacity: 40 L

Price: $235

Pa'lante Packs are truly meant for (and designed by) fast-packing thru-hikers. With only 40L of storage and no frame, the V2 is not recommended for any large—or even moderately heavy—loads. This pack is tiny, compact and sleek. It features virtually no straps, belts or clips.

Available at Pa'lante Packs

Nashville Packs Cutaway

best ultralight backpacks - nashville packs cutaway

Weight: 13 ounces

Capacity: 40 L

Price: $145

The frameless Cutaway offers a modular strap system to fit a mix of the short, tall, thin or wide torso sizes. Continuous-material panels reduce seams and weight while the pockets have a unique take on improving accessibility including a front-access bottom pocket.

Available at Nashville Packs

Lite AF Curve 35

best ultralight backpacks - Lite AF Curve

Weight: 1 lb

Capacity: 35 L

Price: $255

The Curve is a capable 16 oz. pack that can be bought outright, quickly giving you a 35L basic-but-capable Dyneema pack. You'll get an extra 10+ liters of storage from the external pockets. Grab yourself a custom version of this model and you’ll be swimming in color options and other customizations.

Available at LiteAF

Additional Considerations


Yes, we’re talking about ultralight backpacks but by no means have we forgotten about comfort.

Shoulder straps make an impact on comfort so don’t overlook them. Consider the shoulder strap options, their shape, accessory options like pockets or loops, and how much padding you’ll get for the weight/money.

Next, hip belts and hip belt padding, or lack thereof, can also contribute to comfort in terms of distributing weight and how it feels on your hips.

Lastly, the back panel helps with comfort. Personally, the biggest use I find for the back panel cushion or concave frame is preventing pack items from jabbing into my back. 

Removable back panel can be used as a cushion (Gossamer Gear Mariposa)


Sizing is all about your torso length, not your height. The manufacturer should have some sort of torso measuring method to make sure you get the right size.

Tighten down or adjust straps like compression straps to keep contents from shifting around or load-lifter straps to help the pack hug your body. It needs to feel right. This baby will be resting on your hips and shoulders and taken off and put back on several times a day. You want to securely clip the belt above your hip bones so the majority of the pack’s weight rides on your hips instead of your shoulders.

*Tip: I often lean forward a bit and take my arms out of the shoulder straps to test how comfortable the weight is if entirely on my hips.

Back panel ultralight backpack


The importance of the frame or back panel has shifted to an emphasis on cushion and breathability. Many packs have a concave back panel to maximize airflow. While helpful, take this ‘airflow’ with a grain of salt. Even with some of the most breathable packs on the market, you can still sweat like a pig.

You might find breathable mesh in other areas that can make a pack attractive, too. Hip belts or shoulder straps can have mesh for breathability and less friction. You might really enjoy that if you typically deal with pack rub, especially if you have skin sensitivities.

Let’s not overlook the front pocket, either. A mesh front pocket is common which gives hikers a place to air out damp items giving breathability to a space that would otherwise trap moisture. It’s almost essential.

Removable hip belt ultralight backpackRemovable hip belt (Superior Wilderness Designs Long Haul 50)


In ultralight hiking, many packs are water-resistant, made from nylon face fabrics treated with a DWR coating. They’re more breathable, comfortable, and durable than fully waterproof bags, and though they will eventually get wet, paired alongside a pack cover or liner (or both) they can keep your gear good and dry through drizzles and downpours. 

Fully waterproof bags are more geared towards water activities like rafting/kayaking. Ideally, you can submerge the bag in water and the inside will remain dry. They’re made with waterproof zippers and flaps, roll-top enclosures fully sealed seams, and often a combination of waterproof fabrics like Dyneema and PVC materials. Waterproof bags often run at least $100 more and don’t expect a lot of external pockets.   

  • Pack cover: A pack cover may come with your bag already, or you can buy one. They come in a range of sizes and go over the outside of your bag to keep it dry, though some hikers find them to be a hassle because they limit access to your bag. In moderate rains, they do a decent job at keeping your bag dry but beware of high winds. Pack covers are notorious for flying off. 

  • Pack liner: A tried-and-true item that’s been around for years, liners go inside the bag, lining the interior and cinching or rolling at the top to protect its items inside. Trash compactor bags also work well as a cost-efficient option, but are more prone to tearing. With liners, keep in mind that the outside of your pack will remain exposed, so if it gets drenched, it’s going to get heavy. 

Bottom pocket on ultralight backpack
A bottom pocket can be convenient for stashing items like a rain jacket
(Atom+ by Atom Packs)


  • Straps: some packs come with compression straps that help secure the load and make it more comfortable to carry. Load lifters and chest straps also help with overall comfort and balance. Hiking with a bear canister? Why not consider a pack with bear canister straps like the Zerk 40?
  • Pockets: although ultralight backpacks tend to minimize the use of pockets, there is a wide range of storage options you'll still need to consider. Do you care for a shoulder pocket to hold your smartphone? Do you want storage on your hip belt for quick access items like a knife or a compass? You may also find a bottom pocket handy for storing trash or wet gear.
  • Hip belt: not all hip belts are created equal. Some are more padded than others. Some are wider than others. If versatility is important to you, you may enjoy having the option to remove the hip belt altogether. Test out different options and see which one's best for you.

Packing and Organization

Put the features of any backpack to good use and contribute to your own comfort by learning how to pack effectively. Distributing the weight in your pack properly will save you pain and avoidable frustration.

Start by packing heavy camp gear closest to your back in the main compartment,then mid-to-light camp gear, followed by the mid-to-light gear you’ll access throughout the day. Stow quick-access, lightweight gear in your exterior hip, chest, and side pockets.

how to pack a backpack illustration

Getting organized will help you quickly access your gear and keep things clean and dry.

  • Grab a few stuff or compression sacks and organize things by like-kind such as kitchen items, food, clothing, and your sleeping bag/quilt respectively.
  • Help things stay dry with a pack liner or cover.
  • Dry items that will inevitably get wet by situating them outside of your pack exposing them to sun and wind to dry as quickly as possible.

More on packing and organization in How to Pack a Backpack: THE Complete Thru-Hiker's Guide

Chris Cage photo

About Chris Cage

By Chris Cage Chris launched Greenbelly Meals in 2014 after thru-hiking the Appalachian Trail for 6 months. Since then, Greenbelly has been written up by everyone from Backpacker Magazine to Fast Company. He wrote How to Hike the Appalachian Trail and currently works from his laptop all over the globe. Instagram: @chrisrcage.
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