The new Beta SL jacket features a three-layer 40dx70d Gore-Tex material with a PFC-free ePE membrane, making it the most lightweight model in Arc'teryx's highly popular Beta line. It was previously labeled the “LT” model, but is now referred to as “SL” for “superlight.”

Our Verdict
The new Beta SL jacket features a three-layer 40dx70d Gore-Tex material with a PFC-free ePE membrane, making it the most lightweight model in Arc'teryx's highly popular Beta line. It was previously labeled the “LT” model, but is now referred to as “SL” for “superlight.”
Our Analysis and Test Results
We thoroughly enjoyed wearing the Beta SL, even in prolonged storms, alpine monsoons, and wet snow storms near the coast. This garment handled everything we threw at it, and it is worthy of your consideration if performance is prioritized over price. This is a high-end jacket that skews more on the hardshell end of things, so it can double as a ski shell during winter.
Water Resistance
Despite its modest weight, the Beta SL is an excellent jacket for weather protection, performing admirably over weeks of field testing. From steady drizzles to monsoonal downpours, our underlayers remained mostly dry, with just a little water making its way through at the sleeves and around the neck area due to various movements leaving openings for rain to sneak in slightly.
As we got further along in our testing process and the jacket began to get dirty, it was essential to wash/dry the Beta SL to re-activate the DWR (durable water repellent) coating. We found that when the fabric became dirtier, the jacket allowed moisture inside slightly, particularly in the shoulders and chest areas, where the rain first hit.
The material used in this garment boasts three-layer 40d x 70d Gore -ex with an ePE membrane, which is the latest update from Gore. The “ePE” stands for expanded polyethylene, which is more environmentally friendly and claims to make the jacket lighter and more durable. An ePE membrane is thinner than the commonly used PFAS membrane, making the face fabric more robust. Additionally, PFAS are now known to be harmful to the environment and the wearer, and laws dictating their removal from design have gone into effect worldwide. Most gear manufacturers are working to remove PFAS from their products, if they haven't already done so. Bottom line, this rain jacket outperformed the competition in our review in this metric and is among the most impressive we've tested.
In our more objective shower testing, the Beta SL further confirmed this excellent water resistance assessment with only 2 square inches of wet spots appearing. This pricey garment is worth your hard-earned cash if you need top-tier weather protection. For shoppers needing an even more robust jacket for inclement weather, check out our review on the best hardshell jackets.
Breathability
Since most shoppers will use their rain jacket while recreating outdoors, how the Beta SL, and every other option, performs when engaged in sweaty activities was an important metric to evaluate. The Beta SL came in towards the top of the lineup in this metric.
In our experience, any jacket designed primarily to repel water can't also be highly breathable, so our scoring in this metric is more about the relative performance between the two. As mentioned, the Beta SL has a thinner membrane than its previous iteration, which claims to improve breathability. Thorough testing confirmed this claim. We found the SL among our lineup's more breathable rain jackets. It also enabled us to easily improve ventilation using its pit zips, a feature that does not exist in all Beta models. As with most jackets in testing, breathability significantly improved when moving through cooler temperatures or out on lower output missions. However, if you're on a lengthy uphill hike or climb and it's not raining, we'd recommend keeping your rain jacket in your pack, as you'll likely get wet from the inside out.
Comfort and Mobility
The Beta SL scored fairly well in comfort and mobility, but its slimmer cut put some of our review team between sizes. The fit can be adjusted to some degree by simply sizing up or down one size, but some shoppers may find one size too loose, and another too tight. Our main tester found a men's small to work well when wearing just a base layer underneath the Beta SL. Still, it got tight when adding more insulation or participating in more arm-intensive activities like climbing. With a medium, our tester found the Beta to be more versatile for year-round use, though it was a bit baggier fit overall.
The C-KNIT backer technology boasts a much better next-to-skin feel than many rain jackets, improving the overall score of the Beta SL in this metric.
Weight
At 11.15 ounces, the Beta SL came in towards the top of the pack.
This is a fairly light rain jacket, particularly considering its excellent performance in other metrics. The “SL” stands for superlight, and while we wouldn't go as far as to call it “super light”, its weight is far more reasonable than other high-performing shell jackets.
Construction Quality
The Beta SL offers a generally superior quality of construction, setting a high bar in the world of rain jackets. The outer is made with 70 denier nylon in the higher abrasion areas such as the arms and shoulders, compared with only a 40 denier nylon in the lower abrasion areas, such as the torso.
As previously mentioned, the ePE update in the membrane is meant to improve the overall life of the jacket in addition to other performance benefits. Some have reported this model requires more washing and care to maintain its DWR coating. Our experience was similar in practice, slightly reducing its score in this metric. The features of this garment are also well-made and easy to use, though one of the face cinching cords became permanently elongated early on in testing, also bringing its score down a tad.
Should You Buy the Arc'teryx Beta SL?
The Arc'teryx Beta SL offers excellent performance for those wanting a lightweight, high-end product and don't mind a very high price point for a rain jacket. To maximize the performance of this layer, one will need to keep it clean to keep the DWR coating effective, and the sizing might be a touch tricky for some shoppers. At the end of the day, this is undoubtedly one of the best rain jackets available on the market today if you prioritize performance over price.
What Other Rain Jackets Should You Consider?
If price is your main hesitation, look at the Patagonia Torrentshell 3L, which offers excellent water resistance at a fraction of the price. If you're a big fan of the Beta series from Arc'teryx, the Arc'teryx Beta is 20% cheaper than the Beta SL, with top scores across the board, although it isn't quite as water resistant nor as breathable.