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When you’re hiking long distances, every ounce matters. Ultralight backpacks help serious backpackers move faster, cover more miles, and feel less tired at the end of the day. These packs combine smart design with tough, lightweight materials to carry everything you need without weighing you down. Whether you’re planning a thru-hike or just want to lighten your load, the right ultralight pack can transform your backcountry experience.
1. Hyperlite Mountain Gear Southwest 40 (2400)
Built for hikers who push their gear to the limit, this pack has earned legendary status on long trails. The Southwest 40 weighs just 29 to 30 ounces but handles abuse like a champ thanks to its Dyneema fabric construction.
Instead of fragile mesh that tears on branches, you get solid side pockets that actually survive off-trail scrambles. The internal frame keeps loads comfortable up to about 40 pounds, though most ultralight hikers carry less.
With 40 liters inside and nearly 10 more liters in external pockets, there’s room for multi-day food carries. The highly water-resistant fabric sheds rain and morning dew without needing a separate pack cover, making this a top choice for thru-hikers who demand toughness under two pounds.
2. Hyperlite Mountain Gear Junction 40 (2400)
What happens when you take the Southwest’s proven design and add a mesh front pocket? You get the Junction 40, a more versatile pack for hikers who move between trails and cross-country routes.
That big mesh pocket up front is perfect for drying wet socks, a rain jacket, or your tent fly while you walk. The solid side pockets still protect water bottles and snacks from sharp rocks and brush.
Weighing about 30 to 31 ounces depending on size, it handles loads up to 30 pounds comfortably and can stretch to 40 with careful packing. The same tough Dyneema fabric and internal frame give you confidence on long expeditions, while the smart pocket layout makes this a true do-everything pack for serious backpackers.
3. Gossamer Gear Mariposa 60
Many backpackers call this their first serious ultralight pack because it doesn’t feel scary or stripped-down. At 33 to 35 ounces, the Mariposa 60 keeps weight low while offering features that make the transition from heavier packs easy.
The pivoting hip belt moves with your body instead of fighting it, and seven external pockets put everything right where you need it. With 60 liters of space, you can carry bulky quilts or extra layers without playing Tetris.
The PVT frame carries loads up to 35 pounds surprisingly well, perfect for long water carries or week-long food hauls. Reviewers consistently praise its comfort and smart design, making it ideal for backpackers ready to go lighter without giving up all the comforts they know.
4. Gossamer Gear Gorilla 50
Once you’ve trimmed your gear list and don’t need 60 liters anymore, the Gorilla 50 becomes incredibly appealing. This compact sibling to the Mariposa weighs 32 to 35 ounces in medium size with belt and frame included.
With about 50 liters total capacity split between a 32-liter body and 18 liters in pockets, everything stays organized and accessible. The sweet spot for this pack is loads up to 30 pounds, right where most experienced ultralight hikers land.
You still get the robust suspension and excellent pocket layout that made the Mariposa famous, just in a tidier package. Backpackers who have refined their systems love how this pack carries medium loads without extra bulk, making it a favorite for weekend trips and section hikes alike.
5. Zpacks Arc Haul Ultra 60L
How light can a framed pack actually be? The Arc Haul Ultra answers with an astonishing 21.7 ounces while still carrying real weight on your hips.
The secret is a curved carbon-fiber frame that tensions the backpanel away from your body, creating airflow and transferring load efficiently. Made from Ultra 100 fabric (tougher than DCF in abrasion tests), this pack resists both water and trail wear.
With 60 liters of capacity and a recommended max load of 30 pounds, it’s built for thru-hikers counting every gram. The ventilated design keeps your back cooler on hot climbs, a huge bonus during summer miles. If you’re serious about weight savings but refuse to give up hip-belt support, this pack represents the cutting edge of ultralight engineering.
6. ULA Circuit / Ultra Circuit (68 L)
Walk any section of the Pacific Crest Trail and you’ll see this pack again and again. The Circuit has become a workhorse legend because it balances ultralight weight with serious hauling ability.
Weighing 32 to 36 ounces (lighter in the Ultra fabric version), it offers a generous 68 liters for big water and food carries. The carbon-fiber and Delrin suspension hoop works with foam padding and a single aluminum stay to control heavy loads beautifully.
Multiple surveys show it’s one of the most common packs on long trails, trusted by thousands of thru-hikers. When you need to carry five liters of water through the desert or a week of food between resupplies, this pack handles it without complaint, making it perfect for ultralight-leaning backpackers who occasionally go heavy.
7. Granite Gear Crown3 60
Imagine owning one pack that transforms from traditional to ultralight depending on your trip. The Crown3 60 makes that possible with its clever modular design.
At 2.4 pounds without the lid, it’s light enough for serious UL hikers. But add the removable Vapor Current framesheet and optional lid, and you’ve got a pack that handles 35-pound loads for longer expeditions.
With 60 liters of space, there’s room for four-season gear or extended food carries. The best part? You can strip out the frame when your base weight drops, running it frameless to save even more ounces. For backpackers who want flexibility without buying multiple packs, and who appreciate not spending a fortune, the Crown3 delivers exceptional versatility that adapts as your skills grow.
8. Osprey Exos 58
For hikers moving from 3 to 4 kilogram packs, the Exos 58 feels like a revelation. Weighing just 2.9 pounds in small/medium (under 3 pounds for most sizes), it delivers Osprey’s famous comfort and warranty in an ultralight package.
The tensioned mesh Airspeed backpanel creates serious ventilation, keeping you cooler on sweaty climbs. With 58 to 61 liters depending on size, you won’t outgrow it quickly.
The removable lid lets you trim weight once you’re confident with your packing system. Thru-hikers love having a mainstream brand behind them with strong customer support and easy warranty claims. If you want to go lighter but aren’t ready to trust a cottage brand yet, this pack bridges the gap beautifully while keeping you comfortable mile after mile.
9. Durston Gear Kakwa 55
When a thru-hiker designs a pack, you know it’ll handle real trail conditions. Dan Durston’s Kakwa 55 has quickly won over gear reviewers by balancing true ultralight weight with surprising load support.
Coming in under 2 pounds depending on size, it uses Ultra 200 fabric that’s actually tougher than many DCF packs. About 55 liters plus external pockets give you room for longer carries.
The brand says it handles up to 45 pounds, but most find 35 pounds the comfortable sweet spot. What makes this pack special is how it doesn’t force you to choose between weight savings and carrying ability. Experienced ultralight backpackers who occasionally need to haul heavy loads appreciate having a pack that does both jobs confidently without compromise.
10. Mountain Laurel Designs Prophet 48
Frameless packs scare some people, but for hikers with base weights under 10 pounds, the Prophet 48 represents the cutting edge of ultralight design. At just 17 to 18 ounces in recent Ultra and Ultra X versions, it practically disappears on your back.
With 48 liters of capacity, there’s room for food and essentials without excess space flopping around. The catch? This pack is optimized for loads rarely exceeding 20 to 25 pounds total.
If you’re carrying more, the lack of frame becomes painful quickly. But for highly experienced ultralighters who’ve mastered their systems, the Prophet offers incredible freedom of movement. You need to know how to pack efficiently and move smoothly with a frameless design, but the weight savings make every mile feel easier.
11. Atom Packs Atom+ (EP50)
Hand-built in the UK, the Atom+ has cult status among European thru-hikers and is gaining fans worldwide. The EP50 variant offers about 50 liters in a pack weighing just 25 to 26 ounces in large size.
Smart features include a removable carbon-fiber frame, removable hip belt, and integrated shoulder strap pockets that keep snacks within easy reach. The bottom pocket lets you grab layers or food without stopping to dig through your main compartment.
What sets Atom Packs apart is the custom options and refined cottage-industry attention to detail. Each pack is made to order, so you can specify exactly what you need. For hikers who want smart on-trail access and appreciate the craftsmanship of small-batch gear, the Atom+ delivers performance and personality in equal measure.
12. Waymark Gear Co. Lite 50
Not everyone wants to go full ultralight immediately, and the Lite 50 understands that perfectly. Aimed at transitional hikers who still carry a few luxuries, it weighs about 34 to 35 ounces with aluminum stays and hip pocket included.
With 50 liters total (roughly 40 liters in the body plus 10 in pockets), you have room for a slightly heavier sleep system or extra comfort items. Made from EcoPak EPX200 fabric, it’s built to handle abuse.
The internal frame with two removable aluminum stays carries up to 30 pounds comfortably, perfect for when you’re not quite ready to cut every luxury. For backpackers wanting a durable, semi-custom ultralight pack that forgives heavier setups, the Lite 50 offers a smooth path toward lighter hiking without feeling punishing or extreme.
