5 Best Ultralight Backpacks for Thru Hiking, Ranked and Tested

Thru hiking strips gear down to what earns its place on your back for weeks or months at a time, and no piece of kit gets scrutinized harder than the pack itself. We picked this shortlist by weighing carried weight against real load-hauling capability, durability against trail conditions, and price against what a hiker actually gets for it. Every pack here has proven itself on long trails, not just in a gear closet.

The picks, reviewed in detail

Best Overall

Zpacks Arc Haul Ultra 60L

The Arc Haul Ultra earns the top spot because it does something few ultralight packs manage: it carries a real load while staying under 22 ounces. The arc frame bows away from your back, creating a gap that keeps you cooler on long climbs and distributes weight through the hip belt rather than your shoulders. Thru hikers logging real miles report it holding up well under daily abuse, including one hiker's account of 30 straight days on the Appalachian Trail without complaint. Ultra 100X fabric is the reason it can be this light and still survive scree fields, granite, and rain without babying. This is not a pack for hikers who want to stuff it to the brim with car-camping comforts; the arc frame rewards a tight, well-considered load and can feel unstable if you overpack or pack top-heavy. Torso fit matters more here than on a standard internal frame, so hikers between sizes should size down rather than up. For anyone who has already cut their base weight and just needs a pack that won't add unnecessary ounces back, this is the one to beat.

Lightest Full-Feature Dyneema

Hyperlite Mountain Gear Southwest 55L

The Southwest 55L is built around a simple idea: one pack that adapts to nearly any trip without asking the hiker to compromise. Dyneema construction means the fabric itself is doing double duty as both structure and weatherproofing, so there's less need to stuff everything into a pack liner or worry about a sudden downpour soaking your quilt. At 30.8 ounces it is not the lightest pack here, but it earns that weight back in versatility, handling shoulder-season loads and slightly heavier food carries better than packs optimized purely for minimum weight. The notes describing it alongside the Windrider point to a shared design philosophy rather than a single trail-specific tool, and that shows in how well it handles varied terrain and trip lengths. Field reports on Dyneema packs consistently note the fabric's resistance to abrasion from granite and brush, which matters over a thousand-plus miles. The tradeoff is cost: at over $400 this is the most expensive pack on the list, and hikers on a budget will feel that. It's the right call for someone who wants one pack to handle everything from a long thru hike to shoulder-season trips with a slightly heavier kit.

Best for Shoulder-Season Versatility

Hyperlite Mountain Gear Windrider 55L

The Windrider 55L is, by the brand's own framing, cut from the same cloth as the Southwest: a do-it-all pack built to handle nearly any adventure without redesigning the formula. It shares the Southwest's Dyneema fabric and its $420 price tag, which makes the choice between the two largely a matter of fit preference or feature layout rather than performance. On trail, that shared DNA means the same benefits: fabric that resists tearing on rock scrambles and brush, minimal water absorption in wet weather, and a build that holds its shape under a loaded pack better than most ultralight nylon options. Thru hikers who've tried both often pick based on how the harness or pocket configuration sits on their particular torso rather than any meaningful weight or durability gap. Where the Windrider makes sense is for hikers who've already tried the Southwest's fit and found it slightly off, giving them a nearly identical alternative rather than a genuinely different pack. It carries the same tradeoffs too: this is not a budget pick, and hikers looking to save money should look elsewhere on this list. Treat it as a sibling option to the Southwest rather than a separate tier.

Best Value

Durston Kakwa 55

The Kakwa 55 makes the strongest case for value on this list, landing at $279 while still delivering a sub-2-pound carry weight that puts it in the same conversation as packs costing significantly more. It's built from what the maker describes as first principles of load carrying and ergonomics, and that shows in a fit that prioritizes weight distribution over flashy fabric technology. For a hiker outfitting a first thru hike attempt or working with a tighter gear budget, this is the pack that lets the rest of the kit list stay ultralight without a four-figure spend on the pack alone. It won't match Dyneema's abrasion resistance or near-total water resistance, so a pack liner becomes more important in wet climates or brushy terrain. What it does deliver is a genuinely lightweight carry without asking hikers to pay a premium fabric tax for it. Long-distance hikers who've put serious miles on it report solid comfort under load, though it doesn't carry quite the same brand pedigree or multi-year trail reputation as some of the pricier options here. For most budget-conscious thru hikers, the math on this pack is hard to argue with.

Best for Heavier Loads

Gossamer Gear Mariposa 60

The Mariposa 60 is the pack for thru hikers who haven't yet trimmed their kit to the bone and need something that can comfortably haul a heavier load without punishing the hips and shoulders. At 33 ounces it's the heaviest pack on this list, but that extra weight buys a frame and harness built to carry more than the featherweight options here can comfortably manage. Recycled Robic nylon is tougher and more resistant to cuts and abrasion than it might sound, holding up well against rock scrambles, brush, and the general wear of daily trail use over hundreds of miles. The pocket layout is a standout feature, with enough external storage that hikers can keep water, snacks, and rain gear accessible without digging through the main compartment at every stop. This is not the pack for someone chasing the lowest possible base weight; it's the pack for someone still carrying camp shoes, a bulkier sleep system, or extra food between resupplies. Its reputation on trail is well established, and that track record matters for hikers who prioritize proven reliability over weight savings. For anyone transitioning from traditional backpacking into ultralight, this is the most forgiving on-ramp on this list.

At a glance

What to look for

Pack weight matters, but it should never be evaluated in isolation from what that weight buys you. A pack that saves four ounces but sacrifices hip belt support or torso fit will cost far more in comfort and fatigue over a thousand miles than it saves in base weight. The packs on this list span from 21.8 ounces to 33 ounces, and that range reflects a real tradeoff between minimalism and load-hauling capability rather than simply better or worse engineering. Hikers should weigh their own base weight target against how much comfort margin they're willing to give up to hit it.

Fabric choice drives both durability and price more than almost any other spec on a pack. Dyneema composite fabrics, used in the Southwest and Windrider, resist tearing and shrug off water in a way that woven nylons simply cannot match, but that performance comes at a real cost premium. Robic nylon, as used in the Mariposa, offers a more traditional durability profile at a lower price point, while newer fabrics like Ultra 100X aim to split the difference, delivering Dyneema-like performance at competitive weights. None of these fabrics are wrong choices; they represent different bets about where a hiker wants to spend money and where they're willing to accept tradeoffs.

Frame design deserves more attention than most first-time ultralight buyers give it. Arc frames, like the one on the Arc Haul Ultra, create a gap between the pack and the back for airflow and shift load onto the hips in a way that can feel dramatically different from a conventional internal frame. That design rewards careful, minimal packing and can feel less stable if overloaded or packed poorly. Conventional internal frame packs, by contrast, tend to be more forgiving of imperfect packing at the cost of some ventilation and a few extra ounces.

Price should be evaluated against expected trail life and the rest of a hiker's kit, not in isolation. A $420 Dyneema pack that lasts multiple thru hikes without needing replacement may cost less per mile than a cheaper pack that needs repair or replacement mid-trail. That said, not every hiker needs or can justify premium fabric technology, and the Kakwa 55 proves that genuinely lightweight, well-designed packs exist under $300. The right call depends on how many miles a hiker expects to put on the pack and how much of their budget is already committed to the rest of an ultralight kit.

• Confirm torso length sizing before buying, since fit affects comfort more than any single spec on the pack
• Check hip belt design and padding if you expect to carry loads on the heavier end of a pack's intended range
• Consider your climate: near-waterproof fabrics like Dyneema matter more in consistently wet regions
• Look at pocket and external storage layout relative to how often you need quick access to water, snacks, or rain gear
• Weigh the pack's frame style against how disciplined your packing habits actually are, not how disciplined you intend to be
• Factor in expected trail mileage and durability needs against the pack's price rather than comparing price alone

How to choose

Hikers chasing the lowest possible base weight who have already dialed in the rest of their kit should look first at the Arc Haul Ultra, since its arc frame and Ultra fabric deliver the best weight-to-support ratio on this list. Those who want Dyneema's durability and near-waterproof performance but need a bit more structural versatility across trip types should choose between the Southwest and Windrider, treating the choice as a fit preference rather than a performance decision. Budget-conscious hikers, especially those planning a first thru hike, should start with the Kakwa 55, which delivers competitive weight without the Dyneema price tag. Hikers who haven't yet trimmed their base weight down, or who consistently carry bulkier gear like camp shoes or extra food, will be more comfortable in the Mariposa 60's more forgiving, higher-capacity build. In general, prioritize fit and load-carrying comfort over chasing the single lightest number on a spec sheet, since a pack that hurts by mile 800 costs more than the ounces it saved.

FAQ

Related guides

Keep building your system with these closely related guides.

• Ultralight Backpacks: 9 Packs Compared per Liter and Load
• 6 Proven Overnight Packs: What Denier Actually Tells You About a Fabric
• Hyperlite Southwest Review: 40, 55 and 70 L Compared
• PCT Gear Guide: Best Ultralight Backpacks for the Trail

Further reading

Authoritative sources to go deeper on the topics above.

• Leave No Trace
• backpacking checklist