Osprey Exos Pro 55L Backpack Review

Osprey Exos Pro 55L Thru Hiking Backpack

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This is an in-depth review of the Osprey Exos Pro 55L Thru-Hiking Backpack 2024. This is the latest upgrade to the very popular Exos series of backpacks from Osprey. It is now lighter than ever and still the most comfortable thru-hiking backpack on the market.

If you are looking for an ultralight backpack that is still very comfortable and has space for an internal hydration pack, and enough room in the side pockets to carry a 4L water bladder on each side then there is nothing else out there that is better.

I recently took the new Osprey Exos Pro 55L backpack out to test it and was very impressed. I’ve extensively used and tested the older Osprey Exos models having used them on a combination of 4 thru-hikes totaling more than 10000 miles. And this new model has the same level of quality but is lighter.

The Osprey Exos Pro 55L recently took out the award for the most comfortable thru-hiking backpack in the review of the best ultralight backpacks on the market in 2024.

Keep reading to find out more about the Osprey Exos Pro 55L Thru-Hiking Backpack.

How We Tested

The Osprey Exos Pro Backpack in this review has been extensively evaluated and researched by the expert author who has more than 30 years of experience in Thru-Hiking, Backpacking, and Hiking. He also spent several years managing a hiking retail store and is regarded as an expert in this field. It was supplied by the manufacturer for this review. It has been rigorously tested by the author in all kinds of weather on multiple backpacking trips. The research, testing, and experience of the author have combined to present this honest and unbiased review. Read the Review Policy for further details.

In-Depth Review of Osprey Exos Pro 55L Backpack 2024

Osprey Exos Pro 55L Review

Osprey Exos Pro 55L Thru Hiking Backpack Review

Weight: 33.2 oz / 942 g (S/M size)

> Ultralight
> Large capacity 55L
> Great for thru-hiking
> Large side pockets
> Bearvault 500 fits horizontally which makes this perfectly suited to places such as the JMT and PCT.
> Not waterproof, needs a pack cover or internal pack liner
> The removable lid is only extra weight and not that functional for most ultralight hikers

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The Osprey Exos and Osprey Eja backpacks have been some of the most popular lightweight backpacks on the market for many years. The newly released Exos Pro and Eja Pro are lighter in weight, just as functional, and are easily the most comfortable lightweight backpacks on the market in 2024.

I’ve used the regular Exos for more than 10000 miles / 16000 km of hiking and backpacking around the world and the new Osprey Exos Pro is everything that the old model was but in a lighter weight and with a couple of handy upgrades.

When I took the Exos Pro on a couple of hiking trips to test the pack, I liked the new silicon section on the back of the hip belt which keeps the pack locked in place better than before. The continued use of hipbelt pockets after removing them a few years back is great. They are big enough for most large smartphones, snacks, and more.

The Osprey Exos Pro is one of the few lightweight backpacks that still offer a hydration sleeve for your hydration bladder which I like. When testing the backpack I used a hydration bladder a couple of times which worked well. The side pockets are still the best in class for storage and accessibility. While some backpacks need the hiker to be double-jointed to access a water bottle when hiking, the Osprey Exos Pro makes it very easy with the dual entry side pocket. I wonder why other manufacturers haven’t tried to copy or emulate this awesome design! It is the best out there at the moment.

The outer fabric is lighter than previous models and made from recycled materials. You will still need a waterproof backpack cover or internal pack liner to keep things dry when the weather turns nasty as the pack is only water resistant. To keep things dry and accessible there is the removable lid which I’m not a fan of. During testing, I removed it and found the backpack works well by just using the small lid flap to keep the backpack closed and dry.

The ventilated frame does a great job and allowing air to flow around your back. The adjustable shoulder straps, load lifters, and comfortable harness all combine to make this a super comfortable backpack. If you want to have a lightweight backpack that is very comfortable, then look no further this is the best one out there. Sure, other packs are lighter, and others are more comfortable, but in my opinion, this backpack offers the best balance of comfort and weight. I’m sure this will be a very popular thru-hiking backpack.

Overall, the Osprey Exos Pro is the most comfortable lightweight backpack on the market for 2024. Keep reading to learn about every little detail about this backpack.

Osprey Exos Pro 55L comes in two sizes and is very adjustable
Osprey Exos Pro 55L comes in two sizes and is very adjustable


The Osprey Exos Pro 55L is one of the few ultralight packs that have a ventilated frame design. The frame has a durable mesh panel that allows air to circulate between your back and the backpack. The frame is supported by metal poles along the side of the pack and across the top and bottom of the pack.

When I tested this pack in hot conditions, I found the ventilation to work quite well, especially when there was a bit of wind to keep the air circulating. Unlike some other packs that feature a ventilated back system, the main body of the pack is far enough away so that a poorly packed backpack doesn’t result in objects poking you in the back such as cook pots and stoves. During testing, I tried to pack the backpack as poorly as possible to try and get the sharp objects on my back and but the design of the backpack prevented this from happening. Well done Osprey on this small but important feature.

Overall, the Osprey Exos Pro frame is an improvement over previous models and they managed to do all this and keep the weight down. I wonder what a carbon fiber frame and the use of Ultra Fabric would look like on this backpack!


The shoulder straps on the Osprey Exos Pro Backpack are light, breathable, and dare I use the word again, comfortable. The harness can be adjusted up or down to make it longer or shorter in back length. As well as having a sternum strap and load lifters.

The harness comes with a couple of extra details that come in handy. There is a breathable panel at the top of the shoulder straps to allow air from around these notoriously sweaty sections of the body. Speaking of breathable, the back panel is a quality mesh material that allows air to circulate around the back. All this is held form by metal frame stays that also form part of the adjustable shoulder straps mechanism.

There are no shoulder pockets or water bladder hose clips on the shoulder straps which would be a nice addition, but as this is a minimalist backpack it makes sense not to load up the features too much.

There is not much to be critical of, other than the lack of shoulder strap pockets or water bladder hose clip. The whole harness and shoulder strap system work in harmony together.

Hip Belt

The hip belt is comfortable and works as it is supposed to. There is enough padding to keep things pain-free and the addition of a silicone pad at the rear serves to assist with keeping the hipbelt and pack in place rather than allowing it to slip around when hiking.

There are pockets on both sides that are big enough for smartphones, snacks, lip balm, etc. One of the pockets comes with a zip and the other has a flap to keep things in place. Backpacks with hip belt pockets will always score well as a desired feature when seeking out a backpack.

The Osprey Exos Pro Hip Belt pockets are large enough for large sized smartphones
The author testing the Hip Belt pockets that are large enough for large-sized smartphones


The Osprey Exos Pro 55L is the lightest backpack on the market that is very comfortable to wear. Weighing under the metric one-kilogram and around the two-pound mark makes them very light. But what is impressive is that the comfort of the backpack actually seems to make it feel lighter than it actually is. Not sure what kind of illusion is going on here but if you try it on for yourself you will know what I mean.

And they can be made even lighter than the official specs by removing the top lid. By doing so you can save a couple of ounces.

Weight Specs:

  • Exos Pro 55L – 33.2 oz / 942 grams (S/M)
  • Exos Pro 58L – 34.6 oz / 982 grams (L/XL)

Carrying Capacity and Size

The Osprey Exos Pro is only available in the 55L size at the moment. There is no word from Osprey to confirm if any other sizes will be made available in the future, but I suspect they will look at expanding the size range at some point.

The size will be perfect for thru-hikers and anyone who has trimmed their backpacking gear list to include lightweight and compact gear. That means most people will have no issue carrying several liters of water and enough food for a couple of days of backpacking. If you want to carry more gear there is room in the external rear pocket, and there are webbing loops to clip extra gear if needed. If you find yourself carrying excessively heavy loads and having to strap things to the outside of the pack, then maybe consider another backpack that is larger and heavier for your needs. Nonetheless, it is good to know that it is there if needed.

The 55L Exos Pro will fit a standard-sized bear canister horizontally inside the pack. So if you find yourself on the Pacific Crest Trail or John Muir Trail then this pack will be a good option for you.

Material and Durability

The new Osprey Exos Pro uses an upgraded lightweight fabric called Nanonfly. It is 100 denier and rather light and soft to the touch. High-wear areas use a heavier 200 denier fabric, and there is mesh on the side pockets and parts of the rear pocket. And I should mention there are 2 Ice Axe Loops should you need them.

The Osprey Exos Pro durable fabric
The Osprey Exos Pro is light and durable

Water Resistance

The Osprey Exos Pro 55L is water resistant, and just like the regular Exos and the older model the Levity, it is quite good at keeping the water out. But it is recommended that you use a backpack cover or waterproof internal stuff sack for your gear. The fabric is coated with a DWR finish but don’t expect it to last very long as the wear and tear of use will cause it to wear off quite quickly.

Sizes and Fit

The Osprey Exos Pro 55L is available in 2 back-length sizes, namely a Short to Medium torso length of between 17-21 inches / 43-51 cm, and a Large to Extra Large which is for lengths between 19-23 inches / 48-58 cm.

I tested the small-medium size and found it to fit perfectly and have a good level of adjustment.

Carrying Water and Side pockets

The side pockets on the Osprey Exos Pro are the best of any ultralight backpack.

When testing the backpack I was able to carry a 4L water bladder in each pocket, which is 8L in total. While most people would never consider doing this, it is good to know the possibilities. For normal use, I was able to fit a total of 4x1L smartwater bottles, a hiking umbrella, tent poles, and trekking poles into the two side pockets with ease. Only the new Hyperlite Mountain Gear Unbound 40L was able to come close, but it lacked the ease of access of the Exos Pro. If desert hiking you will love these pockets. Thru-Hikers on the Pacific Crest Trail will especially love this feature.

The Osprey Exos Pro has a hydration bladder sleeve inside the main body of the backpack. The sleeve features a loop that you can use to hang your bladder. It also features a clip that will work with Ospreys’ brand of water bladder. The exit port is at the top of the sleeve and allows you to choose if you want the hydration hose to be on the left or right. A cool improvement could be a hydration hose clip but maybe that is asking too much.

Overall, the side pockets work well for water carrying and anything else you might want to carry in the side pockets. They simply work better than anything else on the market at this weight limit.

Large capacity dual entry side pockets and internal hydration sleeve means great carrying capacity
Large capacity dual entry side pockets and internal hydration sleeve means great carrying capacity, pictured here carrying a 4L water bladder and drinking from an internal 2L hydration bladder.

Osprey Exos Pro Backpack vs The Rest

The Osprey Exos Pro 55L is the most comfortable ultralight backpack on the market in 2024. Compared to the other lightweight packs from Zpacks, Hyperlite Mountain Gear, and more this pack offers noticeably more comfort. This extra comfort comes at the cost of weight as it is heavier and it lacks the waterproofness of packs made with Dyneema.

Want to know more, read the full in-depth comparison review of the Best Backpacks 2024.

Read the full reviews of the Best Ultralight Backpacks 


The Osprey Exos Pro 55L comes in at a very reasonable price compared to the competition in the ultralight backpack range. There are cheaper options out there but not many will be as lightweight as this and able to carry up to 40 lb in weight. Although I would recommend that you keep your pack base weight below that.

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The Osprey Exos Pro is an ultralight backpack that is the perfect combination of durability, lightweight, and comfortable. There is simply no other pack on the market that is as lightweight and comfortable. If these are qualities that you value in a backpack then this will be the perfect choice for you.

Overall, this is the most comfortable ultralight backpack. If you choose to get one be sure to try and keep your base weight of less than 13 lb / 6 kg, and ensure you carry less than 40 lb / 18 kg in total to keep this pack super comfortable. If are able to do this, then the pack will be perfect for you.

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Another one of the Best Backpacking Gear Reviews from BikeHikeSafari.

Frequently Asked Questions

Is the new Osprey Exos Pro backpack any good?

The Osprey Exos Pro is the latest ultralight thru-hiking backpack from well-known backpack brand Osprey. Not only is it very light but it is durable and very comfortable.

Osprey Exos Pro 55L Thru Hiking Backpack Pinterest Pin

BikeHikeSafari Gear Review Process

The author, Brad McCartney from BikeHikeSafari is a small independent adventurer and outdoor gear tester who owns and runs BikeHikeSafari.com.

BikeHikeSafari is not part of a large blog network and is proudly independent. All reviews on this site are independent and honest gear reviews of outdoor products by the author.

The author, Brad McCartney is a very experienced triple crown thru-hiker, adventurer, and bike tourer having spent 1000s of nights sleeping in a tent and sleeping bag (Read more). He was a manager of an outdoor retail store and is very experienced in what is important when using and testing gear for reviews like this.

BikeHikeSafari will never receive any money for reviews and they do not accept sponsored reviews on this website. All the comments about the gear reviews are from the author based on his years of experience. Hope this independent review was helpful for you.

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Photo of author
About the Author:
Brad is an Australian who has completed the hiking Triple Crown after he hiked the Pacific Crest Trail, Continental Divide Trail and Appalachian Trail. He has hiked on every continent (except Antarctica) and has cycled from Alaska to Ecuador. He is an expert on outdoor gear currently living in Chile.

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