A thru hiking backpack needs to hold a full kit for days at a time, so start by matching pack size to your longest trip. This roundup covers five packs, but most of them are short-trip packs or daypacks, so read the picks with that in mind. Sizes here run from 15L to 100L, and the right one depends on how much gear you carry. For a closer look, read Best Hydration Bladders: Five Picks and How to Choose One.
For multi-day loads, the first pick is the Vaupan 100L expandable pack. The maker lists an expansion from 70L to 100L with elastic drawstrings, with room for a sleeping bag, mat, hammock and shoes. That means you can run it at 70L for a lighter load and open it up when you need more space.
The other four picks suit lighter outings, from a backup daypack to short hikes and rainy days. Each section below explains who the pack fits and where it runs out of room.
Key takeaways
Match pack size to your longest trip first.
The Vaupan 100L is the first pick for multi-day loads.
Sizes in this roundup run from 15L to 100L.
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How we picked: from products sold on Amazon for this need, compared by what their makers state and what buyers report in their reviews.
The Picks at a Glance
Product | Best for | Compatible device size maximum | Material type | Strap type | Buyer rating | |
|---|---|---|---|---|---|---|
Vaupan 100L Expandable Backpack | 4- to 5-day trips | 15.7 in | 600D Oxford | Shoulder Strap | 4.4 of 5 (285 reviews) | |
W WINTMING 70L/100L Pack | 3-day trips | 19.7 in | Polyester | Shoulder Strap | 4.5 of 5 (5,146 reviews) | |
VOBUYING 15L Foldable Pack | a backup daypack | 13 in | Polyester | Adjustable | 4.5 of 5 (105 reviews) | |
MIYCOO 35L Packable Pack | light rain days | 15.9 in | Polyester | Adjustable | 4.5 of 5 (2,593 reviews) | |
Osprey Sportlite 15L | short hikes | — | Nylon | Adjustable | 4.6 of 5 (42 reviews) |
Buyer ratings as shown on Amazon on October 13, 2026; they change.
Vaupan 100L Expandable Backpack: Best for 4- to 5-day trips
The Vaupan 100L Expandable Backpack is the first pick for 4- to 5-day trips that need room for a full kit. Its main point is capacity: the maker lists it as expandable from 70L to 100L, which is the size range you want when your sleeping bag, mat and hammock all have to fit.
The maker says the main bag has elastic drawstrings that let the pack expand, with enough room for a sleeping bag, mat, hammock or shoes. For you, that means you can carry a shorter trip with the pack at 70L and switch to 100L when you add a few days of food and gear. The pack also has a laptop compartment, a front zip pocket and two side pockets for water bottles or an umbrella. Learn more in How to Test a Backpacking Water Filter Before a Trip.
The maker describes the body as 600D oxford fabric with a water-resistant finish. That fabric sheds light rain and splashes, but it is not fully waterproof, so you should still pack a dry bag or liner for the sleeping bag. Buyers say the pack is well made and comfortable to wear, and that it holds a lot of gear.
Pros
Expands from 70L to 100L for 4- to 5-day loads
Water-resistant fabric for light rain
Several pockets for water bottles
Buyers say it is comfortable and holds a lot of gear
Cons
At 100L it is large and heavier than a shorter trip needs
The fabric is water-resistant, not waterproof, so heavy rain can get in
W WINTMING 70L/100L Pack: Best for 3-day trips
The W WINTMING 70L/100L Pack is the pick for 3-day trips where you carry climbing or heavy gear. Its 70-liter main compartment and 900D Oxford fabric are the stated features that point to that kind of load.
The maker describes a drawstring-closed main compartment that is roomy enough for hiking gear, shoes and luggage. A 19.7-inch device fits in the laptop compartment, so you can carry a larger laptop or tablet in its own pocket. The pack also has one front zipper pocket and two side pockets, which keep small items such as a headlamp or snacks separate from your gear.
The shell is 900D Oxford fabric that the maker calls water resistant, tearable and anti-scratch. Water resistant is not waterproof, so a rain cover or a liner is still useful on wet days. The pack weighs 2.86 pounds and measures 27.5 by 15.75 by 8 inches. An external MOLLE webbing system lets you clip on extra gear such as pouches or a sleeping pad.
Pros
Heavier-duty 900D fabric for rough use on rock and brush.
MOLLE webbing for attaching gear outside the pack.
Breathable, padded shoulder straps with a thickened sponge back panel.
A roomy 70-liter main compartment for a 3-day kit.
Cons
The drawstring-closed main compartment is slower to open than a zippered one, so you will dig for items more often.
The pack is hand wash only, so cleaning takes more effort each time.
It has no internal frame, so a heavy load can ride less firmly on your back.
Look at the Vaupan 100L Expandable Backpack instead if you need more room for a full kit on longer trips.
VOBUYING 15L Foldable Pack: Best for a backup daypack
The VOBUYING 15L Foldable Pack is the pick for a backup daypack, a small bag for day trips or a spare when your main pack is too big. It is light and folds small, which makes it easy to keep in a car or suitcase.
The maker lists a weight of 0.76 pounds and a folded pouch of 7.48 x 7.87 inches. For you, that means the pack adds very little weight to a day load and can be tucked into a suitcase or glovebox until you need it.
The pack has 10 pockets and a main compartment that the maker says fits a 13-inch laptop, tablet, clothes and gear. Buyers repeat that the pockets help keep small items sorted, so keys and wallets are easy to find. The fabric is water-resistant polyester with reinforced zippers, which the maker says shields phones and cash from sudden downpours.
Pros
Very light and compact, so it packs easily into a suitcase or car.
Buyers say it works well as a day pack for grab-and-go items.
Buyers say it is comfortable to wear and does not feel bulky when carried.
Water-resistant fabric and reinforced zippers suit sudden rain.
Cons
At 15 liters it is too small for multi-day gear, and it runs out of room quickly on a thru hike.
If you need to carry a full kit for several days, look at the Vaupan 100L Expandable Backpack instead.
MIYCOO 35L Packable Pack: Best for light rain days
The MIYCOO 35L Packable Pack is for light rain days, and it suits day hikers and people using a pack for workouts who want something light. Its stated water protection and small folded size are the reasons it earns a spot here.
The maker says the pack is about half the weight of a mobile phone and folds down to 4.5 x 3.9 x 7.8 inches. For you, that means it can ride in a suitcase or a jacket pocket until you need it, and it adds very little to your load on a day hike. Unfolded, it measures 12.5 x 8.5 x 20.9 inches, so it holds a day’s gear rather than a multi-day kit.
The maker rates the pack IPX4, which protects against splashes and suits workouts or light rain. A separate wet compartment keeps damp items away from dry ones, and the zippers and major stress points are reinforced. Think of IPX4 as protection from a passing shower, not a downpour.
Pros
Very light and packs small into a pocket or suitcase
Reinforced zippers and stress points
Buyers say the wet compartment keeps wet and dry gear apart
Cons
IPX4 protects only against splashes, so heavy rain can soak the contents
If you carry a pack for several days or in steady rain, look at the Vaupan 100L Expandable Backpack instead, which is water-resistant and built for longer loads.
Osprey Sportlite 15L: Best for short hikes
The Osprey Sportlite 15L is the pick for short hikes and excursions, and it suits hikers who want a brand with strong fit features. Its 15-liter size and adjustable straps make it a daypack, not a pack for multi-day trips.
The maker lists a capacity of 15 liters and a weight of 510 g. That weight is light enough to carry all day on a trail, and 15 liters holds water, snacks and a rain layer for a day out.
The back panel uses mesh-covered foam with airflow channels, so air can move between the pack and your back on warm walks. The hipbelt has padded hipwings, which move weight from your shoulders to your hips. The maker lists one size, designed to fit a broad range of body shapes.
Pros
Buyers praise the airflow back panel and the padded hipbelt for comfort on longer walks.
The safety whistle sits on the sternum strap, where you can reach it quickly.
The internal hydration sleeve fits a reservoir, so you can carry water hands-free.
The main fabric is made from 100% recycled, ocean-sourced nylon.
Cons
The reservoir is sold separately, so you must buy one to use the hydration sleeve.
At 15 liters it is small for multi-day trips, and a sleeping bag and food will fill it quickly.
If you need room for multi-day gear, the Vaupan 100L pack is the better fit.
How do you choose a backpack for a thru hike?
Start with trip length, because it sets the size you need. A 35-liter daypack suits a short outing.
On a long walk, the pack rides on your shoulders and hips every day, so fit matters more than most features. Long-distance hikers often judge packs by how they carry weight.
Some packs have no internal frame, so the padding does most of the work.
Water-resistant is not waterproof. The Vaupan pack is made of durable 600D oxford fabric and water resistant material. A pack rated for splashes protects only against splashes and light rain, so line it or use a liner in wet weather.
Weight and capacity go together. The 15-liter VOBUYING pack weighs 0.76 lb, while the 100-liter Vaupan pack weighs 3.31 lb. A lighter pack with less room may not hold your gear.
Which pack should you buy first?
Start with capacity. Match your pack size to your longest trip, because a pack that is too small runs out of room and one that is too large adds weight you carry every day. Most of the packs in this roundup are short-trip packs, so the choice of size matters more than any single feature.
For a thru hike, the Vaupan 100L expandable pack is the first pick for long trips that need room for a sleeping bag and mat. The maker says it expands from 70L to 100L with elastic drawstrings, which lets you carry a bulky kit on a 4- to 5-day trip and cinch it down when you carry less. Its fabric is water-resistant, so you still need a liner or dry bags in wet weather.
If you plan only short outings, a 15L to 35L pack will fit your gear without extra weight on your back. The smaller packs in this roundup suit day use and backup duty, not a multi-week carry.
When you compare two packs, look at capacity and weight together. A lighter pack with less room may not hold the gear you need.