Arc’teryx Alpha FL Jacket


The hood is helmet compatible and has three points of adjustment. Although the hood felt bulky at first, with some tinkering of the adjustments, I was able to wear it comfortably with or without a helmet. When worn over my Black Diamond Vector helmet, minimal peripheral vision is lost, and overall the fit is protective and snug without significantly inhibiting my range of motion.

Luke Koppa reviews the Arc'teryx Alpha FL Jacket for Blister Gear Review.
Luke Koppa in the Arc’teryx Alpha FL Jacket.

The hood’s performance is equally effective when using ski helmets like the Salomon Hacker and MTN Charge, although with these larger helmets you cannot take the hood off without unzipping. The one area where the hood could be improved is the adjustment toggles, which are small and harder to use with gloves when compared to the new Cohesive embedded cord locks found on some newer jackets on the market.


The Alpha FL has been my go-to hardshell for over two years now, and has seen a lot of abuse. This has included alpine climbing, ski touring, daily bike commuting, and everything in between. I was wary of the Alpha FL’s 40-denier non-ripstop fabric, but the jacket has yet to puncture or tear. Even the shoulders, where backpack straps and ice tools can often cause damage, show no obvious abrasion. For a piece that is designed for the “Fast and Light” system, it has proven to be surprisingly durable.

Bottom Line

The Arc’teryx Alpha FL is a climbing-oriented shell that works well beyond its stated use. The trim fit and ample articulation suit a variety of activities, and the Gore Pro fabric provides reliable waterproofing. The minimal featureset is not for everyone, especially if you prefer to store a lot of stuff in your jacket. You should also look elsewhere if you prioritize breathability over weather resistance. But if you’re looking for a reliably waterproof shell with a slim alpine fit and you do not need too many features, the Arc’teryx Alpha FL is a great option.

4 comments on “Arc’teryx Alpha FL Jacket”

  1. Hi Luke,

    Thank you for your extensive review. I have to say that it is one of the best ones I have read so far.
    I saw that you mention that you layer this with the Atom LT. About the sizing, are they both same size or do you have the Alpha on a bigger size than the Atom?
    I’m about to buy an Alpha in XS, as that’s the size I have for the Atom but as I can’t find a store to try it I’m not 100% sure what to do.


    • Hi Filipe,

      Glad you enjoyed the review! I have both the Alpha FL and Atom LT in a size medium and am happy with both in that size. I like the fit of both when worn together (good range of movement but not too much excess space), but I wouldn’t wear anything bulkier than the Atom under the Alpha FL, as it is a pretty slim fit compared to most other shells.

      Hope this helps, and let me know if you have any other questions!


  2. Hi Luke,

    I am 5’7 145 lbs, planning to buy the Alpha FL for mountain hiking and might possibly use as a shell for winter time also. Only other piece of Arcteryx I own is a Squamish Hoody in XS and it fits really well with just a tee under. Not sure if I should buy the Alpha FL in S or XS as I also plan to layer beneath it? Would love to hear some advice.



    • Hi Darius,

      Thanks for reaching out. I haven’t had the chance to use the Squamish Hoody, but Arc’teryx states that the Squamish features their “athletic” fit which is supposed to be very similar to the Alpha FL’s “Trim” fit. So, if you are comfortable with the Squamish in just a T-shirt, I’d recommend sizing up to a size Small for the Alpha FL if you’re considering layering more than a T-shirt underneath. Although it’s patterned so that you can freely move your arms, the Alpha FL doesn’t have a whole lot of volume to it, and the thickest insulator I find myself layering underneath is a 60 g synthetic midlayer like the Arc’teryx Atom LT or Patagonia Nano Puff Pullover. Hope this helps, and let me know if you have any other questions.



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