Arc'teryx  Aerios 18 Pack

The Aerios 18 was my favorite pack for day hiking, scrambling, low 5th class climbing, for the past 3 years. I live outdoors 6 months per year in the Canadian Rockies: I hike and run long distance, scramble and climb mountains in the Canadian Rockies full time, each and every single day. Over the past 3 years, I’ve recorded over 5000km and around 300 mountain summits with this pack alone. I use a number of different packs for different missions, but consistently choose the Aerios 18 over a plethora of different packs I own. This review is on their latest model (purchased in 2026); I was deeply disappointed, as one of the seemingly “innocent” revisions eliminated a key feature that made this pack better than all the rest. Ultimately, Arc’teryx likely made a change for aesthetic reasons, consequentially making it perform much more poorly. What makes the Aerios 18 great? Perfect size for day hiking. If you think you need more, you are likely taking too much, or don’t hike/scramble hard enough. This enables me to take everything I need to do some pretty hardcore routes and distances in the Canadian Rockies… the vast majority of which are off trail and up mountains. This includes carrying crampons and ice axe if necessary. Minimalist: has a little pocket on the inside for keys or important items you don’t need to access, and a quick one on the outside for snacks. Main pocket is perfect capacity for day missions. Perfect, don’t really need anything else. No genuine mountain athlete actually uses water bladders, even though they provide a slot for this if you think this is important or prefer to use one (hard to make everyone happy). Running vest style: highly prefer this to traditional straps for day hiking, as I run up and down a lot of mountains and it feels comfortable and secure. On my old pack, the horizontal strings would losen during use; I’m not sure if this was a result of wearing over time (if there was a locking mechanism) or if it was a design flaw, but regardless, it wasn’t too much of an issue anyway since the fit was pretty good, and stability was sufficient. That said, the new design uses a paracord type string vs a more elastic bungie type shock cord; I have yet to test if this makes it feel less secure if it loosens during use. Chest strap pockets: I solo run/scramble in some very remote places in the Canadian wilderness; bear spray is non-negotiable and I’ve had numerous close encounters with grizzlies. Bear spray fits perfectly in one of my chest pockets and lives there. I will not use packs that do not have this feature (minus alpine climbing packs). There is a clip in point on the chest strap for a Garmin InReach device, that also lives with me. Water bottle side pockets: essentially why I pick the Aerios 18 over fast/light alpine climbing packs or pure running vest style packs. I want a pack that still has side pockets for smart water bottles. I do not use this pack when I go climbing, typically anything above 5.4 or when I use a rope. I prefer traditional climbing packs for this that do NOT have side pockets for water bottles. But for scrambles, or low class climbs (i.e. Mount Assiniboine), this pack is perfect. From someone who does this full time, everyday, it’s a HUGE deal, trust me. Securing these water bottle in the side pocket… I’ve provided pictures to illustrate this. On the old version, the pull cord on the side pocket was made from a much more elastic bungie or shock cord that could be pulled through the top daisy chain on the side of the bag and looped back around the top of your smart water bottle top, essentially securing the bottle into place tightly. So tightly in fact, that you you invert the bag upside down shake it with full 1L and 1.5L smart water bottles and they would NOT fall out. THIS… was why I used the Aerios 18 over the other 20 or so packs I own, time and time again. I loved this feature, and always wondered to myself if this was intentionally designed to function like this, or just accidental genius. I know other bags in the backpacking market, have similar features. Revised model: This has, unfortunately, been removed from their newest model, as the cord is not nearly (if at all) elastic (paracord type material vs bungie or shock cord), and is significantly shorter than the previous model, which makes it impossible to pass through the daisy chain and loop back around the top of a water bottle. I have had to girth hitch a piece of shock cord to the end to make this work in the newest model… but it is not nearly as tight, as the more elastic version provided much more tension in the whole system. If I honestly think about why I stuck with the Aerios 18 for so many adventures, this was it. This revised version is much more unremarkable in terms of distinguishing itself from other packs on the market. That drawstring through the daisy chain back around the top of the bottle made carrying water on the side of a small bag so BOMBER… and you could still quickly access and stash water in a pinch… with the other features of the Aerios 18, it made this pack nearly perfect as a do-it-all scrambling and day pack. What could improve on the Aerios 18? Revision that eliminated your ability to quickly and effectively secure water bottles in the side pocket (explained above). Fix this. Bungie cords on the outside are arguably pretty pointless. Rarely use them. Not the best way to secure anything to the outside of anything… I use a helmet holder from a different company and attach it to the daisy chains on the outside to hold my helmet. Exactly who in Arc’teryx thinks athletes like to move around with helmets dangling around, or like to spend 15min securing their helmet in place… should be fired from the design team. I’ve picked up enough jackets off the ground in high traffic areas to know that no sane adventure athlete secures anything of actual value to the outside of their pack this way… crampons and ice axe… give me a break. It’s just terrible. I’ve used them, but honestly don’t find much use for them, and just take those plastic bits off the bungie as they will eventually fall off after repeated used and then you don’t have them in the off chance you want/need them. The bungie/shockcord on the newest version has been replaced with something that resembles nylon paracord, and has much less stretch… its predecessor was bad, but this newer version is even more useless at securing things. An open stretchy mesh back pocket like most ultralight backpacks have (for overnight backpacking) would be ideal… this way, if you are not carrying a helmet or ice tools, you can still have a functional pocket for extra quick access capacity; literally adds nothing to the pack weight wise. No dedicated helmet holder. Should be included, unless Arc’teryx doesn’t think mountain athletes are their market audience anymore. Shouldn’t have to use one from a different brand. The one for your winter helmets is unnecessarily heavy and complex. Would much rather prefer this over bungie cord… and is likely lighter than bungie cord (and likely better at stashing a layer, if you thought that was necessary). No dedicated ice axe attachment points. How Arc’teryx puts dedicated ice axe attachments on their 14L running vest but not on this pack, blows my mind. Those loops on the back at the bottom technically work, but then you are faced with contorting the bungie cords to secure the shaft to the bag, which is unnecessarily slow and not exactly secure. Why should mountain athletes be forced to use bags that do not have side water bottle holders to have a secure way to stash ice tools? It weights/costs literally nothing and would make the Aerios 18 perhaps the greatest day pack of all time. No one… no one, stores their trekking poles in these; I store mine inside the pack so I don’t lose them when scrambling or climbing low fifth class terrain. Load lifters. This new revised model has them, but I just don’t know if it was necessary. Moreover, the pull tab is so long that I will be forced to cut it since it comes down nearly to your chest. Those flap around and get very annoying very quickly. Bottomline: Hope this gets through to your design team… I rarely see reviews on Arc’teryx by actual athletes or professionals that have driven your products into the ground and intimately know them. I was so heartbroken when I received my new overpriced pack from Arc’teryx… morally torn as I have literally taken this pack into battle with me on countless adventures. I want to love it, but questionable revisions have undoubtedly made this product worse from a functional point of view. Other than this, some small shortcoming still exist that prevent this pack from being perhaps the best mountain day pack of all time. I don’t mind paying the price if those products are worth it… I do not think I will be buying another Aerios 18 unless I see some key improvements… there are just too many good options on the market for this price. Even though the zippers on my old bag are seizing shut, and the material is falling apart or stiff with dirt and sweat, I am considering returning the new pack and keeping my old one… this is how detrimental secure water bottle placement is to me in the mountains, deep in the Canadian wilderness. I just want bomber side pockets.

I use the Aerios 18 pack for day hikes, long trail runs, and alpine climbing!

I’ve been on the lookout for a daypack that’s light and comfortable without losing functionality. This fits the bill. I think what makes it so unique is the shoulder straps and the way they spread out wide over your shoulders to spread out the weight of the bag and then the twos chest straps come across to secure makes it feel unified with your body. Incredible design. Couldn’t recommend it enough.

Love this backpack!! I brought it with me on a 4 month trip in Asia, and it was the perfect smaller backpack to have. I brought it on shorter 3-4 day excursions leaving my main pack behind, and it was the perfect size to fit clothes, toiletries, a small towel, everything you need. I love the front pockets along the straps as well, It's a perfect spot for your phone for easy storage and grabbing. It also fits very comfortably on the body, and lastly I got major use from the straps on the back of the pack, I would stuff my jacket or shoes in there which made packing all of my stuff a lot easier.

I really had my hopes up because this would have been the perfect backpack.... the specs say that it is water bladder compatible so there is an inside sleeve for the bladder but NO HOOK to keep the bladder in place and there are holes but they are for the shoulder straps and not for the water tube.... so I will have to return it ... really toooo bad because I love the way it fits on my shoulders... oh and the front strap is really goofy.... it doesn't hold the tension...

I picked this up from REI for a lightweight/less technical day hike pack - had 3 days planned in Mt. Ranier (summer - so didn't need the capacity for extra layers). The running vest shoulder straps paired with some external pockets and lash straps was everything I needed externally; I never got close to filling it all the way up. I didn't experience the loosening of the sternum straps (Arc'teryx-specific design/construction) like some have complained about (in fact I quite like them), but wasn't thrilled with how low-cut and angled the side pockets were. Taller water bottles didn't feel fully secured (even when tightened), so I added some packmod bungees on both sides. Would I have liked that in the original design? Sure. But despite it all it's now my go-to day hiking pack. Sizing info: I'm 6'2" 185lbs and the fit is great. Even has small load adjuster straps!

The Arc'teryx Aerios 18 is a quality made pack. It holds about 10 lb. The harness system is made better than others that I have seen of this kind. The two front chest straps seem a little flimsy to me. They are, I guess, made this way to reduce the weight. They hook into the main shoulder straps, which take a little work to get in. But they can be adjusted. I like the material that the main pack is made of. It should last a long time and hold up to adventures through rough country. The "hip belt" does stabilize the pack to allow you to move swiftly, at least it did for small weight for me. The small front pocket does hold sunglasses and a few other small items. The interior zipper pocket is good for small items too. But it is not like the outer small pocket. You can put some medical items, rain jacket, gloves, t-shirt, extra socks, or equivalent inside the main compartment without a problem. What about wet items? Bring a plastic bag. Why? I'm not a fan of the bungee cord system. The one on this pack is easy to adjust. But it goes into the small front pocket. The load lifers help some. If you pull them too much the should straps start to buckle to much for me. I want a smooth "round" strap on my shoulders. I can say much about rain. I did not try it in the rain. My guess is that you'll need a rain cover for downpours. I don't see that snow is a problem. Now, the problem that I had, as well as with others with this harness system, is: It doesn't fit this small body very well. I wanted to run with it as if it were part of my body. It came very close to fitting like I wanted it. But it did not fit good enough. And, lastly, I wonder how it would work when carrying 10 lb at a quick pace for twenty miles. My guess is: if it fits you comfortably and you are in good strong health, you'll be fine. You can attach poles or axe.

LOVE using for school! I use the Aerios 18 for my school backpack. It perfectly fits my computer (macbook air 13) , ipad air, notebook, a book, my 18oz hydroflask, and keys. I like the strap mesh pockets, perfect for straggler hairties, keys, or chapstick. One small thing, if the pack gets too bottom heavy (ipad, heavy calculator), the frame of the back will curve a bit. I usually have no problem because I have my laptop to even out the weight but on those days I don't it looks a bit wonky!

The size is perfect for a day hike. I love the hole for the water bladder and that the backpack has pockets in the front for snacks or your phone so that you have quick access and you don't need to take your backpack off completely. Super comfortable and I like the colour!

It’s a good little backpack but I have a few issues. No water bladder hook to hang inside the reservoir sleeve. No dedicated port for bladder hose. Side pockets are shaped and cut a little shallow so things tend to want to fall out. Arc’teryx also does a terrible job of describing or instructing on using the features of the pack, it’s up to yourself to figure out things like the shoulder straps can be adjusted with the Velcro, what various attachment points are actually designed for, and how to route and hook various components. I also wish there was middle option between the 18L and 35L packs. This is packed full to bursting with a long day hike worth of water, food, layers, and essentials. It also tends to lose its shape and comfort when loaded fully. The 35L is comparatively big, floppy and empty with the same amount of stuff. A 24-28L would be ideal. That being said, when I utilize the 18L for shorter hikes with less stuff and without a water reservoir it’s quite comfortable and feels nice and secure like it’s not even there.