Arc’teryx Alpha FL 45 Backpack

8.4 score
( score (8.4)/10

Our score is based on 3 different factors: Editor's rating after in-depth testing. User ratings submitted on this page Overall score from the "reviewmeter" based on reviews across the web the weight of each factor is: 40% editor rating 15% user ratings 45% reviewmeter.
Editor rating: 8.2 / 10
User's rating: based on 0 user ratings
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Arc’teryx Alpha FL 45 Backpack Review Facts

The Arc’teryx Alpha FL 45 Backpack is restful on the back, weighs less than two pounds, and allows custom attachments. Not only it is comfortable on the back, but it is also easy to carry by hand.  It is a hardwearing pack that is light and fast, and it is the top choice for mountain climbers and ski alpinists. Those who frequently travel by plane also use this pack for their piece of carry-on luggage to keep their personal items with them. It is not only lightweight but waterproof with a laminated exterior. Zippers on the exterior are water-tight, so nothing gets through the metal teeth. The seams are taped for added weather resistance to ensure that no moisture from rain, snow, or sleet will penetrate this pack and affect your internal gear. It is completely seam-sealed for perfect resistance to water. These protections also make the Alpha FL 45 quite durable against abrasions and tears from wear and rough use. As one of the online customers stated in their review of this product, once you get the Alpha FL 45, you will want no other backpack ever. It certainly adds a new element to bringing your gear in the outdoors for trips, hikes, trekking, and mountain climbing. Lets now explore in detail the many advantages and features of the Alpha FL 45 Backpack by Arc’teryx.

Editor's Pros & Cons
  • Is a waterproof item Has multiple uses for outdoor and vacation trips
  • Includes many zippered compartments, loops, and hooks
  • Is comfortable and lightweight on the back
  • Seams are taped for durability and weatherproofing
  • Comes with a bungee cord attachment on the exterior
  • May be a bit floppy when loaded down on the back
  • Could be overstuffed easily because of the huge interior
See How
Reviews were analyzed here:
We read, analyze and sort reviews into positive & negative categories to give you the complete picture.
What are buyers saying?

We have spent 2 hours analyzing a total of 69 reviews.

These reviews are then categoried into "Positive" and "Negative" feedback.

Below you will read a summary of them:

  • For alpine climbing, this is a pack designed to perform.
  • All excessive weight has been stripped so you only have to focus on the weight of what you pack.
  • When thoughtfully packed, it can hold all the necessary gear for a multi-day adventure.
  • The design is simple and streamlined.
  • The inside is spacious.
  • The straps hold the pack close to the body which is ideal for climbing.
  • Straps and the opening are easy to adjust while wearing gloves.
  • The ice axe and tool attachments are simple.
  • It features durable crampon straps that can also be used for other equipment if crampons are not attached.
  • This is 45L when fully expanded so it can comfortably be used as a smaller pack when needed.
  • The interior is white which helps visibility while packing and unpacking.
  • If using a harness with clippers, this hip belt is more comfortable than a fully padded one.
  • The design is ergonomic and functional.
  • Most buyers say this backpack lives up to their expectations of Arc'teryx quality in design and construction.
  • Many buyers are impressed by the toughness of the material.
  • Buyers are pleased that Arc'teryx changed the location of the rope strap from previous generations of this backpack.
  • Packing must be thoughtfully done in order to maximize the design of this backpack.
  • Over packing in weight will lead to discomfort on the neck, shoulders, and hips.
  • There are mixed reviews on the overall weatherproofing design. While the material is waterproof, some buyers report issues of water pooling at the top of the pack.
  • This backpack does not include a rain cover.
  • The bungee system is not secure enough for some styles of ice axes. A few reviewers have had issues with them falling off.
  • The material, like most, has some weaknesses when pushed to its limits.
  • The price is steep.
  • This backpack is 45L when it is fully expanded. Some photos and marketing can be misleading on the size.
  • Over time, the inner lining is susceptible to cracking and wear.
  • The bungee system can get caught while trekking through heavily treed areas.
  • There are no included straps for skis.
  • The sternum strap does not have elastic and is too short for some users.
  • Aside from the small outside pocket, there are no separated compartments. This is good for keeping the weight down, but adds difficulty when packing and unpacking.
The Reviewmeter shows you an overall score that you can easily refer to. The highest rating is 10 (100% positive feedback)
Of the 69 reviews we found in total, 14% were negative, and 86% were positive.


Most buyers who left a review online commented on the supreme comfort of this wonderful pack. They liked the way it felt on their back when moving in difficult terrain and the fact that it does not move around much to throw off their balance. It is a lightweight pack that can hold a great deal of gear, making it very valuable on hikes and trips in the outdoors. The alpha FL 45 weighs less than two pounds and is a comfortable pack to carry. It is secure on the back because it has an HD 80 foam panel on the back to give the user padding, structure, and support when wearing the pack. Weight is reduced by the ingenious design in that the top lid is pushed inside when the user is moving. It, therefore, does not create a problem of additional baggage and can be used again when the bag is full. The drawstring top will suffice when the pack is not filled all the way.


This is a hardwearing pack that is light and fast in the most uninviting of environments. It is as tough as the rugged landscapes that you may encounter and will provide you with a way to carry the things you need the most for your trip. Made of Burly Double Weave material that consists of 8% elastane, 46% polyester, and 46% nylon, it can take much rough and tumble because of its durable weather-proof exterior and interior that makes it so trusted and long-lived. It is not only lightweight and waterproof but also laminated to make it as weather-proof as possible and still be flexible enough to your many needs.
The seams are even taped to make them more durable and tough to prevent tears and rips. For the best pack that can take the elements well in the alpine atmosphere, the Alpha FL 45 is the one to have.


The Alpha FL 45 is one of the most flexible packs you will ever see or use. As one buyer commented after purchasing one, it would be like going back to the dark ages to use anything but this terrific backpack. It allows custom attachments and can carry crampons and extras by attaching to the front bungee cords. This cord can hold rain gear, a light jacket, or small tarp to the exterior for weather protection. This terrific product has two loops for an ice axe, six lash points on the front, and four lash points on the side. It can be clipped on a snow anchor or hauled by the double carry handles or haul loops and has a RollTop closure. It is easily accessible even with gloves on with the big webbed pull-tabs. Also included is a sternum strap that is removable and adjustable, a webbing hip belt, and a shoulder strap that is thermoformed. These aspects allow you to custom fit the pack to your particular shape and desired tightness around the waist and shoulders. Getting this just right prevents the pack from swaying and bouncing when you are moving fast or running.


Of the many features that this backpack possesses, we think some are worth mentioning separately. The front lash points can hold a sleeping pad or skis on the exterior of the pack, and the bungee cord can hold a jacket, ice tools, or crampons. In this way, you can bring so much more with you that just what can fit inside the pack. These outer possessions will not be protected in adverse weather, but a small plastic covering brought along could easily cover these items on the outside too. A rope can be secured by the top strap and the two top loops to allow hauling of the pack. This is where the real benefit of having such a flexible and customized backpack comes in handy. The outer loops and straps are essential for mountain explorations in this way.
You can see things well inside the bag because it has a white interior that is reflective. This also adds its own layer of weather-proof protection for the contents inside the bag. The back panel is rigid to give structure and support to the user, as long hikes and trekking can be hard on the back muscles and hips when carrying a pack. This one sits well on the hips and back in an ideal position. Swaying is minimized with the webbing belt when you are trying to navigate through technical routes. Tightening this belt will ensure that you have the most secure snug fit that is form-fitting to your body. It will help you maintain your balance in precarious situations.


When you are out in your element and the only gear you have with you is in your backpack, you want that pack to be the best you can find. The Alpha FL 45 is that pack. It will support you in whatever environments you choose to explore with its durable, flexible, and adjustable form. You can attach all sorts of gear products onto the sides, back, and front, plus put plenty of things on the inside to bring with you. It has a compression strap on the top and is created for efficient swift movements. This particular model has been improved for the stability of load carry, energy efficiency, and durability to make a more advanced piece of backpacking equipment. It includes an Advanced Composite Construction system of technology to make your outdoor experience the best ever. Additional capacity is obtained with the drawcord and extendable collar, and the included pocket in the main compartment and zippered external pocket that has a key clip. The many ways to organize your gear in such a pack are endless because everything you need for your outdoor adventures can either be put inside this pack or attached to the exterior of it.


Although it is great for ski alpinists and climbers, this superb backpack can also be used as a carry-on for plane trips. Several online buyers purchased this pack especially for that purpose. They wanted a compact way of bringing their much-needed gear with them for long plane rides and trips away from home. Being weatherproof is a big help because you never know what the weather will be like at your destination. It is the top choice for mountain climbing because it allows the hands to be free and it is lightweight. It is a climbing pack made for light fast travel on ice, alpine, ski and rock alpinism routes. You can easily move swiftly with this ideal pack even loaded with gear. It is ideal for rapid speed in highly variable environments and is perfect for extremely harsh conditions. You never have to worry about a rain-soaked pack and dripping wet gear with the Alpha FL 45. It is made for environment and weather surprises that can catch you off-guard. It gives enough space for essentials for a day-long trip for skiing or a minimalist trip for several days. Everything you would need for such outings can be easily packed into this pack that seems to have unlimited space.


The external zippers on this wonderful pack are water-tight, and it is completely seam-sealed for the best water resistance. No water, rain, sleet, or snow should be able to penetrate this terrific backpack. Being extremely weather-resistant, it is resilient to scrapes and created for the rigors of granite and ice. It is coated on the outside and inside of the pack, so it resists the penetration of air, water, and other weather conditions. The weather conditions in the mountains can be so unpredictable, but you can be ready for anything that comes your way with this pack. It can hold rain gear for an unexpected shower or a small flashlight or headlamp if you get caught out after dusk. The essentials will always be with you when you have this weatherproof pack to protect all of your gear.

Ease of Use

The Alpha FL 45 gives more flexibility and packing interior than the company’s Alpha FL 30. Both are outstanding bags but this one is larger without significant weight gain. This increases accessibility and speed in getting to the interior and is perfect when heavier loads are required. The pack volume can be decreased or increased as needed without issue. The RollTop folds into the interior and is not in the way when it is not necessary. The pack can be sealed easily by the drawstring collar when the RollTop is not used. This pack’s flexibility and durability make it easy to use and trust for all of your backpacking and trekking needs. You can customize and pack it with just what you will need on your trips to make them the most enjoyable and fulfilling.

The Bottom Line

The Alpha FL 45 is an excellent pack that is made for enduring extremely harsh environments. It gives protection against alpine environments to the gear entrusted inside and can take the punishments of weather and wear. This terrific pack is ideal for high speed in the variable circumstances you may encounter in the outdoors. It is enriched for consistency of carrying load, durability, and efficiency. Its best features are the RollTop closure, rigid back panel for support, and the many straps, loops, and belts that are on it for hooking things on while you move about freely. You can make swift movements with this pack even if it is fully loaded because it rides comfortably on the back. Even if you are wearing gloves, you can get to items on the inside of the bag easily because of the webbed pull-tabs. The white reflective interior allows you to see everything in the bag well even in poor lighting. You can hook almost anything you need for climbing and hiking onto this back and stuff it with gear that will fit inside. The Alpha FL 45 Backpack is a remarkable product created by Arc’teryx that we highly recommend for your next alpine excursion or climbing adventure.