Arc’teryx Aerios 18 Backpack | Tested and reviewed

Promising low weight and durability in equally healthy doses, we test the Arc'teryx Aerios 18 Backpack to see if that's true.

LFTO tester wearing Arc’teryx Aerios 18 Backpack

by Chris Williams |
Published on

The ultralight approach to hiking is really gaining momentum. With each season we find brands are launching more and more lightweight gear including backpacks. Arc’teryx is pushing this trend as hard as anyone. Exhibit A: the Aerios 18 Backpack.

The appeal of lightweight hiking is obvious. The lighter your load, the more agile and speedy you are on the trail. We certainly enjoy that aspect of it, but we’re also highly conscious of the durability (and often sustainability) trade-off.

Despite weighing a featherweight 567g, Arc’teryx promises excellent durability and abrasion resistance from the Aerios 18 thanks to the use of a clever material called Hadron LCP (Liquid Crystal Polymer). So with potentially low weight and high durability, we were keen to find out whether the Aerios 18 lived up to expectations.

LFTO tester reaching for drink bottle our of Arc’teryx Aerios 18 BackpackLFTO
Price: £160.00


  • Super lightweight
  • Great for fast 'n light hikes
  • Impressively durable face fabric
  • Loads of hydration strorage


  • No stash pocket
  • No raincover
  • Not suitable for carrying heavy loads

Design and features

Arc’teryx Aerios 18 Backpack front pocket

Although the Aerios 18 is one of the lightest backpacks we’ve ever tested, it’s armed with an impressive array of features.

At the front, there is a bungee cord and daisy chains for attaching equipment externally, plus two trekking pole loops. There is no front stash pocket, which is a common addition to many hiking daypacks, but there is a medium sized zipped pocked that can accommodate items such as a map or even a lightweight insulated jacket.

The main compartment has a smaller zipped pocket for valuables and has a key clip. There is also a hydration sleeve. Some customers have critcised the Aerios pack for its lack of dedicated tube hole, but Arc’teryx has made the slits for the shoulder straps serve that function.

Arc’teryx Aerios 18 Backpack hydration tube hole

They’re tight but worked fine for us. It's not the only hydration stroage option though, because there is also a pocket on each shoulder strap that can take a 500ml soft flask, plus two standard drink bottle sleeves.

Arc’teryx Aerios 18 Backpack back panel and straps

The back system itself is reasonably basic. The outer of the back panel is mesh, which holds your back slightly away from the main panel and has lots of indents to aid ventilation. The shoulder straps have some light padding, plus two sternum clips and a very basic but removable waist strap.

Performance and comfort

LFTO tester wearing Arc’teryx Aerios 18 Backpack

On test we found the super low weight of the Aerios 18 really pays dividends. If you pack it with the sort of gear you’d take on a day hike – liquids, lunch, a couple of spare layers, plus whatever accessories you like to use – you hardly notice you’re wearing it, except for the sound of sloshing water in the bladder or bottle.

Front stash pockets are handy for quickly stuffing away or grabbing additional layers, but we didn’t really miss their absence on the Aerios 18. The top zip pocket, and usefulness of the little mesh pockets in the shoulder straps that are big enough for a phone or snacks, more than made up for it.

LFTO tester reaching for drink bottle our of Arc’teryx Aerios 18 Backpack

Likewise, the drink bottle sleeves are superb because you can grab a drink bottle and put it back without tacking the pack off. They aren’t elasticated but use a drawcord instead. You can loosen the cord, grab the bottle, put it back, and tighten it again all with one hand.

In terms of comfort, the Aerios 18 is nicely ventilated and delivers a pleasant carrying experience, so long as the load is kept light. The back panel isn’t adjustable but for a small pack, it doesn’t really matter.

Now the big question: is it durable? Somewhat surprisingly, it is. That fancy sounding Hadron LCP fabric is impressively resistant to abrasion. That said, all the other components of the Aerios 18 – clips, zips, straps, and mesh materials – are still just as prone to potential durability issues as any other lightweight pack.


Arc’teryx Aerios 18 Backpack brand stitching

As the outdoor industry wrestles with the substantial challenge of sustainability, demand is simultaneously rising for lightweight gear, which is – generally – not especially eco friendly, primarily due to being far less durable and relying on the use of synthetic materials.

It’s more of the same with the Aerios 18: super lightweight and fully synthetic. Looking at Arc’teryx as a brand, it is working to improve its circularity of products through ReBird and ReGear; improve the conditions of its manufacturing facilities through Fair Trade Certification; and improve the eco credentials of its materials through Bluesign and innovations such as Gore-Tex ePE.

But these things are still in their infancy and we look forward to Arc’teryx making big strides in its sustainability efforts.

Price and competition

Arc’teryx Aerios 18 Backpack and rivals

At the time of writing, the Aerios 18 costs £160. That’s quite expensive for a little daypack, and the Arc’teryx logo doubtless has plenty to do with that top end price. And there is no shortage of models to rival the Arc’teryx Aerios 18, although there aren’t many that are as featherweight.

Berghaus’ Freeflow 24L Rucksack has a similar look and price. Where it differs from the Aerios pack, however, is that it has a more sophisticated back system and is much better for carrying heavier loads – but the Freeflow also weighs twice as much as the Aerios.

If you can cope with a 200g weight increase, Mammut’s Lithium 20 (we’ve tested the 25-litre version) is a much more financially appealling alternative to the Aerios 18, while also offering plenty of features and better eco credentials.


In its own right, the Arc’teryx Aerios 18 is a good daypack. Its super low weight, breathability, and impressive range of features makes it a brilliant option for fast hiking in summer.

But as is always the case with Arc’teryx products, it’s expensive, and doesn’t offer the best value compared to most of its competitors. But when has that ever stopped people flocking to the dead bird?

How we tested

Chris Williams hiking in Lake District wearing Artilect Divide Fusion Stretch Jacket

Chris Williams (pictured above) is one of our staff writers and carried out our test and review of the Arc’teryx Aerios 18 Backpack, primarily in the Yorkshire Dales.

Chris has been with LFTO since 2021 and has several years of journalistic and outdoor industry experience, in addition to a lifetime’s worth of hiking.

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