Feathered Friends Swallow UL 20 Review

Feathered Friends is a legendary name in the down products world, and for good reason: Their gear is top-notch and consistently delivers when it comes to performance. The Swallow UL 20 sleeping bag is case in point. Thanks to its impressive warmth-to-weight ratio, it’s become a go-to in my backcountry kit, tagging along on plenty of climbing, mountaineering, and ski touring missions over the past year. With a just-roomy-enough design that brings a touch of home to the mountains and a utilitarian feature set—including a full-length zipper and cinchable hood—it’s built for versatility in a wide range of three-season (and dipping into four-season) conditions. Below, I break down my experiences with the Swallow UL. For a broader comparison, check out our guide to the best backpacking sleeping bags.
 

Table of Contents

• Warmth and Insulation
• Weight
• Packability
• Features
• Build Quality and Durability
• Sustainability
• What We Like/What We Don't
• Comparison Table
• The Competition

Performance

Warmth and Insulation

Since picking up the Feathered Friends Swallow UL 20 sleeping bag, it has become a consistent player in my backcountry kit. It’s proven itself as the ideal companion for a range of outdoor objectives, including a fall backpacking trip in Wyoming’s Wind River Range, an early season bivvy at Washington state’s Cathedral Lakes, and, most recently, a long weekend on the Eldorado Glacier in the North Cascades (plus plenty of car camping in between). Its 20-degree rating makes it a solid choice for most three-season trips, and I’ve even used it on some colder backcountry ski missions in Washington. Where many 20-degree bags will technically get you through a 20-degree night (usually with some shivering), the Swallow UL keeps you genuinely comfortable at that temp. With the right layers (think mid-winter insulation) I’ve even pushed it into the single digits—not cozy, but manageable.
 

Packed with over a pound of premium 950+ goose down (1 lb. 1.8 oz. in the long version I tested, 1 lb. 0.8 oz. in the regular), it's no surprise this bag insulates so well. The draft tube and cinchable hood also do a great job of sealing in heat. On warmer nights, I appreciated the full-length zipper for ventilation. I tend to run warm and found it a bit hot above 35°F, though my partner, who runs colder, was comfy using it into the 40s. If you usually camp in milder temps, Feathered Friends also offers a 30-degree version of the Swallow UL.

Weight

There are many reasons the Swallow UL tops our sleeping bag round-up, but its weight-to-warmth ratio is certainly the leading factor. Weighing just 1 pound 12.7 ounces for the long version I tested (1 lb. 11.3 oz. for the regular), the Swallow earns its ultralight label. It competes closely with other high-end 20-degree bags like Western Mountaineering’s UltraLite (1 lb. 13 oz.) and Therm-a-Rest’s Parsec (1 lb. 12 oz.), while offering higher fill power (950 vs. 850 and 800, respectively). To be sure, you can certainly go lighter with options like Feathered Friends’ own Tanager CFL 20, which cuts weight dramatically (1 lb. 2.6 oz.) by ditching the zipper and hood and using ultra-thin 7-denier (D) fabric. That said, I prefer the Swallow UL’s extra comfort and versatility, even at a slight weight penalty.
 

Packability

When packed into the included stuff sack, the Swallow UL compresses to about 18 x 10 inches, which can eat up a decent amount of space in an overnight pack. I’ve occasionally stuffed it into a more compressible sack to save space, though I avoid doing this regularly to protect the down. That said, its high fill power and tough fabric can make it a bit stubborn to compress, and the cinch on the included stuff sack broke after a few too many aggressive tightenings. This isn't a dealbreaker for me however, and I still reach for the Swallow over more packable bags in my gear closet because I know I’ll sleep well when it counts.
 

Features

Hood

Sleeping bags aren’t exactly feature-rich, but the Swallow UL has some thoughtful touches. The hood, for instance, cinches down snugly on cold nights and can be opened wide when it’s warmer (Feathered Friends dubs it a “3D hood”). While the passive collar seems a bit basic given the price (an active collar can be cinched down to trap heat), I didn’t experience any drafts when the hood was properly cinched.
 

Shape

While the Swallow UL’s mummy shape is fairly traditional, I found it more than comfortable for multiple nights in the backcountry. Some bags, like Nemo’s Disco 25 Endless Promise, have wider shapes to accommodate active sleepers, but I was able to bend my knees and elbows with no restriction. The trapezoidal footbox is an especially nice touch, allowing generous foot room to avoid compressing the insulation. And since I’m 6’3”,I went with the long version, which is designed for users up to 6'6". It’s a bit heavier than the regular (designed for users up to 6'), and will cost you $20 more, but the added legroom is more than worth it.
 

Build Quality and Durability

As expected from Feathered Friends, the Swallow UL 20 is impressively durable. The 10D Pertex Endurance shell has stood up to plenty of abuse, from being stuffed into tight packs to the odd brushes with sharp gear and dog claws (though I wouldn’t recommend making a habit of that). It also offers solid water resistance, which proved essential when snow camping in my floorless Hyperlite Ultamid tent. Inside, the 15D ripstop nylon liner helps this bag withstand seasons of heavy use. The drawcord and snap on the hood still work like new, and the zipper is smooth and rarely snags, which is a small but much-appreciated detail.
 

Sustainability

Sustainability is a hot topic in the outdoor gear industry of late, and Feathered Friends is one of the leaders in ethical down practices. All their down, including what's used in the Swallow UL, is 100% RDS (Responsible Down Standard) certified. You can also enter details about your bag into Down Tracker, so you can trace the origin and composition of your bag’s insulation. While I’d love to see more recycled materials used in future versions, Feathered Friends’ current efforts are definitely a step in the right direction.

Other Versions and the Egret UL 20

I tested the long version of the Swallow UL 20, which adds about six inches in length and just under an ounce in weight compared to the regular version (1 lb. 12.7 oz. vs. 1 lb. 11.3 oz.). Feathered Friends also makes a 30-degree version of the Swallow UL, which features the same premium 950+ fill power but with a lighter fill weight (13.6 oz. for the regular size), making it a better pick for milder backpacking conditions. The Swallow UL 30 comes in a bit lighter (1 lb. 8.1 oz.) and cheaper ($569), yet still retains all the same features and durable fabrics. It’s also available in a long version (recommended for users up to 6’6”) and comes in four colorways. Lastly, the Swallow UL doesn't come in a women's specific version, but the Egret UL 20 shares all of the same features as the Swallow—including the 950+ fill power and 10D Pertex Endurance shell—but its shape is tailored specifically for a more feminine form and features greater fill around the footbox and chest.
 

What We Like

• With 1 pound 0.8 ounces of 950+ goose down fill, a cinchable hood, and a draft tube along the zipper, this bag is seriously warm and ideal for cold three-season conditions.
• Among the lighter weight sleeping bags in its class, at 1 pound 11.3 ounces (1 lb. 12.7 oz. for the long version).
• Full-length zipper can be opened and hood can be widened to provide ventilation on warmer nights.
• 10D shell and 15D liner hold up well to regular use, and zippers, snaps, and cinches have proved similarly durable.
• Generous mummy shape and trapezoidal footbox is comfortable for active sleepers.
• Feathered Friends' down is ethically sourced and RDS-certified.
   

What We Don’t

• Thick fill and durable materials make this sleeping bag tough to stuff down into the included stuff sack.
• Expensive at $629 for the regular length ($649 for the long).
• There are lighter weight and less expensive sleeping bags on the market (that said, the Swallow UL boasts a premium quality that most alternatives can't match).
   

Comparison Table

The Competition

With its unbeatable warmth-to-weight ratio and premium craftsmanship, it’s easy to see why the Swallow UL remains a top choice for backcountry sleeping bags. Still, there are a few other options worth considering. From within the Feathered Friends lineup, the Hummingbird UL 20 is a slightly lighter and more affordable alternative to the Swallow. For $20 less, you get the same fill power, fabrics, and features as the Swallow in a 1-pound 8.2-ounce package, though its narrower mummy shape might not be as comfortable for active sleepers. If you’re looking to shed serious weight, the Tanager CFL 20 is another Feathered Friends option that’s significantly lighter and cheaper (1 lb. 2.6 oz. and $469 for the regular). However, its 7D fabric is less durable, and the lack of a hood or zipper limits its use to very specific conditions.
 

Outside the Feathered Friends ecosystem, Western Mountaineering’s UltraLite offers similar build quality and features, including a full draft collar and top-notch hardware. It uses slightly less down (16 oz. of 850-fill) and has narrower dimensions, but you do get slightly thicker 12D fabric. For thru-hikers or hardcore ounce-counters, ultralight quilts like Enlightened Equipment’s Enigma are worth a look. The Enigma’s open-back design wraps around a sleeping pad to cut weight while maintaining warmth. At 1 lb. 5.9 oz., it’s lighter than most bags and costs just $465 for the 950-fill version. You do sacrifice a hood and have to pay extra for a draft collar, but it’s a great alternative for the minimalist crowd. Still, for backpackers looking for the ideal combination of comfort, weight, and durability, we continually point to the Swallow UL 20.
Back to the Feathered Friends Swallow UL Review   See our Backpacking Sleeping Bag Guide