12 Best Ultralight Down Jackets for Thru-Hiking for 2021

by Kelly Hodgkins
July 28, 2018

© Paul “PIE” Ingram

At a Glance:

‣ Down jackets weigh close to nothing, yet provide great insulation for your upper body.

‣ Down’s kryptonite is water. When wet, down feathers lose their insulating property.

‣ When choosing a down jacket, consider its overall weight (12 oz or less), fill power (at least 700), and fill weight (30% and up).

‣ Look for down that’s be sustainably sourced (compliant the Responsible Down Standard).

When temperatures start to plunge, you'll want an insulated jacket in your pack. Filled with airspaces that trap your body heat, a down jacket offers the best warmth-to-weight ratio of any type of insulation. These jackets are warm, lightweight, and extremely packable. Let's break down the differences between synthetic vs down insulation. We'll also go over the best ultralight down jackets on the market.

Price Weight Fill weight
Mountain Hardwear Ghost Whisperer $300 7.4 oz 800-fill goose down
RAB Microlight Jacket $250 14 oz 700 fill goose down
Arcteryx Cerium LT $349 9.9 oz 850 fill goose down
Feathered Friends Eos $339 10.6 oz 900 fill goose down
Outdoor Research Illuminate $249 12.5 oz 800 fill goose down
Mammut Broad Peak Light $279 8.6 oz 800 fill goose down
Forclaz Trek 100 by Decathlon $79.99 10.2 oz 800 fill duck down
Patagonia M's Down Sweater $229 13.1 oz 800 fill goose down
Cotopaxi Fuego Hooded Jacket $230 14 oz 800 fill goose down
Marmot Ares $175 15.5 oz 600 fill goose down
Montbell Plasma 1000 $329 4.8 oz 1000 fill goose down
Uniqlo Ultralight Jacket $59.90 8.3 oz N/A

In a hurry? Skip straight to the reviews.

Why Down Insulation (vs Synthetic)?

down insulation vs synthetic


Contrary to popular belief, down is not a feather, and it does not have any quills. Down actually is the soft plumage that lies beneath the feathers of aquatic birds like ducks and geese. It is a light and fluffy cluster of natural fibers that provide an extra layer of insulation for the bird on which it is found.  

  1. ULTRA LIGHTWEIGHT: By far the biggest advantage. Down has an outstanding warmth-to-weight ratio because of its unique three-dimensional shape. The arrangement of the down filaments creates airspaces that trap in body heat. This natural airy construction also makes the material light in weight. For the same level of warmth, a synthetic jacket will be heavier than a down coat and won't compress as much.
  2. EXTREMELY PACKABLE: Another huge advantage. Because it is so light and fluffy, down can be compressed to a fraction of its original size, allowing you to squeeze a down jacket into any small nook and cranny in your pack. Once removed from a compression sack, down quickly will regain its loft and heat-trapping ability. You can repeat this cycle of compression and lofting with minimal damage to the down fibers.
  3. LONG LIFE: Down can be compressed over and over again, making it's insulation ability last a very long time. Alternatively, synthetic fibers break down and lose their ability to trap heat. An older 30-degree bag may become a 50-degree bag because of this wear and tear.

uniqlo down jacket packedUniqlo down jacket packed


Synthetic insulation is designed to mimic the qualities of down that make it such an effective insulator. It uses polyester fibers that are woven together to form heat-trapping air pockets similar to those naturally found in down. Common brand names are Primaloft, Polartec, and Thinsulate. The pros of synthetic insulation are:

  1. INEXPENSIVE: Umm, like half the price. Synthetic insulation can be mass produced making it, often, significantly less expensive than down. Its lower price tag makes it an attractive alternative for people who want warm jackets that won't break the bank.
  2. WATER RESISTANT: Down will lose its loft and ability to retain heat when it gets wet, but that is not the case with synthetics. Synthetic insulation maintains its loft and keeps you warm even when it is wet. It is a must-have if you are backpacking in areas where rainy conditions are prevalent. This is considered to be the "Achilles heel" of down - how vulnerable it is to getting wet.  
  3. WASHABLE: Down is a pain in the butt to wash. It requires using a very specific and expensive type of detergent to wash at home... or needs to be taken to the cleaners. Drying it can be tricky as well because direct sunlight can damage it. However, synthetic is usually much easier to clean and wash like normal clothes. 

mountain hardwear ghost whisperer down jacketMountain Hardwear Ghost Whisperer

Down Jacket Considerations


Fill power is a measurement of the loft, or fluffiness, of the down material. Specifically, it is the amount of space (cubic inch) an ounce of down will occupy at its maximum loft. This commonly advertised value can range from 300 to 900. The higher the number, the more loft the down will have and the better it will be at insulating. A higher fill power will require less down to keep you warm which is why most ultralight jackets use at least 650 down and heavier entry-level down jackets use 300 to 500 down.

ultralight down jackets fill power montbell900 Fill Power on Montbell EX Light


Down jackets should be lightweight and packable, that is one of the reasons you are willing to cough up the extra money, so make sure it is not bombarded with clunky zippers, heavy fabric, etc.

FILL WEIGHT (percentage):

Fill weight is the amount of down (ounces) used in the jacket. Ideally, you want down to occupy 30% or more of the jacket’s total weight. Both fill power and fill weight contribute to the overall warmth of a coat. When comparing jackets with the same fill power, a higher fill weight means a warmer jacket. This feature gets trickier to evaluate when you are comparing jackets with different fill powers. A higher fill power down requires less down for the same amount of warmth, so a 900-fill coat with 3-ounces of down may be warmer than a 500-fill jacket with 5-ounces.


While goose and duck down are similar in warmth, compressibility, and durability, they do have their differences. 

Goose: Goose down has been, and still is, considered the higher value. It’s naturally warmer and lighter, and because geese are larger than ducks their plumage is bigger and loftier. Goose down is less available than duck and it’s the more expensive option of the two. 

Duck: Duck down has gained popularity in recent years as it’s easier to get, cheaper, and it holds up better than goose when wet. But since goose has a naturally higher fill power, it will always remain lighter than duck, especially the higher in quality you go. However, modern-day technologies have developed a system of sorting, clumping, and weaving bunches of duck fibers together that can make it comparable to goose.   

DWR (Durable Water Repellent):

As good as down is, it has an Achilles heel, and that is moisture. Get a down jacket wet from sweat or rain, and it will lose its insulating power. DWR is a water repellent coating applied to the outside of jackets, sleeping bags and other outdoor gear as a first line of defense against moisture. It also is now being used internally to coat down fibers, so they don't lose as much of their loft and dry faster when they get wet. Nikwax, DownTek, DriDown are common brands of hydrophobic down.  


Controversy over how down is collected has led to the rise of Traceable Down and the Responsible Down Standard. Traceable down means the outdoors manufacturer can trace their down from the farm to factory, while the Responsible Down Standard is a voluntary standard that ensures that down-producing ducks and geese are being treated humanely.  Both standards ban the practice of live plucking, which is the injury-causing removal of down from living animals.


Most down jackets are typically made with high-quality ripstop nylon that resists scuffs, scrapes, and tears. The thickness of this outer material is measured in denier, the weight of a thread. The lower the denier, the lighter and thinner the fabric. The nylon varies from jacket to jacket with ultralight jackets minimizing weight by using lighter denier nylon that requires some extra gentle handling. Most down jackets also have some form of outer DWR treatment to resist moisture.


Down jackets are constructed using compartments called baffles to help evenly distribute the down. Baffle size can also have an effect on the insulating qualities of a jacket. Larger baffles can hold a lot more insulation and have more space for loft, but this space also allows the down to clump together producing cold spots. Smaller baffles are more challenging to construct, but they prevent clumping and provide an even distribution of insulation. Smaller baffle jackets also tend to be less puffy, making them ideal for layering under a shell.

outdoor research helium down jacketOutdoor Research Helium down jacket zipper


Whether your down jacket has a hood or not is personal preference. Some people like the coverage a hood provides around the head, neck, and shoulders, while others don't want the added bulk and cost associated with a hood. If you opt to go hoodless, you can always use a beanie or balaclava.


Pockets are another optional feature on jackets. Removing the pockets sheds some weight, but you might miss that extra storage space or convenient hand holder.


Some down jacket manufacturers add an extra lining to help retain heat or wick away moisture. Linings add weight to a coat so you may opt for a jacket that is not lined and use your own layering system to add warmth or cooling as needed.

arcteryx cerium lt down jacket hoodArc'teryx Cerium LT hood

Best Down Jacket Models

Mountain Hardwear Ghost Whisperer

ultralight down jackets - mountain hardwear

Price: $300

Weight: 7.2 oz

Fill weight: 2.65 oz

Fill power: 800-fill 

Shell material: Whisperer 7D x 10D Ripstop Nylon

The Mountain Hardwear Ghost Whisperer is a daaarn light (and warm) jacket that folds up into its own pocket. The jacket's small baffles and trim, athletic fit make it perfect for layering and stowing on the go.  The hooded version is one of the lightest hooded down jackets available.

Don’t be fooled by its ultra-light design, this jacket will certainly keep you warm. When it comes to down material, it also has a more durable design and it holds up better than most in light amounts of precipitation. The fit runs slim, especially across the waist, so if you like some extra room in your jacket, best size up.

🛒 Available at mountainhardwear.com. Also sold in a women's specific model.

ultralight down jacket montbell plasma

Montbell Plasma 1000

Price: $329 

Weight: 4.8 oz

Fill weight: 1.6 oz

Fill power: 1000-fill

Shell material: 7D Ballistic Airlight rip-stop nylon

With 1000 fill power down, the Montbell Plasma has the highest fill power and the lightest weight on our list. It is highly compressible and minimal in design. The outer fabric is made from a whisper-thin 7D ripstop nylon, and there are no interior or exterior pockets. There is no hem adjuster so you may lose some warmth through the bottom of the jacket if the fit is not snug.

The fit is unique because it feels more like a sweater than a jacket, making it a comfortable wear alone, or an easy piece to layer underneath of a shell. It’s best suited for most 3-season hikes. Admittedly, it feels a bit too thin and might the be the BEST for warmth though.

🛒 Available at Montbell. Also available in a women's specific model. For a slightly heavier (and warmer) option, check out Montbell's Ex Light Down Anorak (7.6 oz, 900-fill down).

ultralight down jackets - rab microlight jacket

RAB Microlight Jacket

Price: $250

Weight: 14 oz (Large)

Fill weight: 4.4 oz (Large)

Fill power: 750 fill European goose down

Shell material: Pertex Quantum Microlight

The Rab Microlight is warm and windproof thanks to its 750-fill down and Pertex outer shell. With YKK zippered hand pockets and chest pockets, the Rab Microlight is excellent for storing small items that are easily accessible. It also has an attractive design that you can wear on the trail or a night on the town.

The European goose down keeps you toasty in temps in the low double digits, and the jacket's drawcord hem and inner wind flap along its zipper work well in blocking cold breezes. The jacket has an athletic, flexible shape, although the fit runs snug for most, especially on the sides and armpits.

🛒 Available at amazon.com. Available for women.

ultralight down jackets - uniqlo ultralight jacket

Outdoor Research Illuminate

Price: $249

Weight: 12.5 oz

Fill weight: 2.85 oz (L)

Fill power: 800 fill goose down

Shell material: Nylon

This jacket has several nifty features like an adjustable hood, special internal “Shove-it” pockets for gloves, a carabiner loop, a zippered internal media pocket, a key clip, and a built-in stuff sack that doubles as another pocket. There is also a drawcord hem and elastic “low-pro binding” cuffs to keep wind and weather out.

The Illuminate is thoughtful in its design and a warm choice for protecting in ranges below freezing. The outer material is more durable for a down jacket as it’s made with a rip-resistant, 10 denier nylon shell. As for fit, it runs slim despite its label as a regular fit.

🛒 Available at amazon.com. It’s available in a women’s version.

ultralight down jackets - uniqlo ultralight jacket

Mammut Broad Peak Light

Price: $279

Weight: 8.6 oz

Fill weight: 2.46 oz, 28%

Fill power: 800 fill goose down

Shell material: Pertex Quantum Material

Made with Mammut’s special soft, wind and water-repellent Pertex Quantum material, this down jacket is one of the warmest on our list. It’s impressively weather-resistant (for down) with a straightforward, ultra-warm design making it a suitable match for 4-season hikes, or any skier looking for a midlayer while hitting the slopes.

It’s also one of the best options for mountaineers because of its dual climbing and backpack harness-friendly zipper pockets. It comes in an athletic/trim fit with a longer, elastic-banded waist and a double-zipper system. The jacket packs down into its own left front pocket, coming out no larger than a water bottle.

🛒 Available at amazon.com. A women’s version is offered.

ultralight down jackets - uniqlo ultralight jacket

Patagonia M’s Down Sweater

Price: $229

Weight: 13.1 oz

Fill weight: N/A

Fill power: 800 fill power

Shell material: recycled polyester ripstop shell.

The poster child for down jackets and one of the longest-running companies in the game, this puffy sweater-style jacket is a favorite for backcountry adventurers and urbanites alike.

It has interior and exterior zippered pockets, one of which doubles as a stuff sack with a clip. The front zipper on the jacket has a storm flap to protect against wind and light precipitation, and the bottom hem tightens with a drawcord. The jacket is designed with recycled materials, traceable down, and an environmentally friendly DWR finish that all comes together to create a semi-slim fit, leaving a comfortable amount of room for layering.

🛒 Available at rei.com. The jacket’s also available in a women’s version.

ultralight down jackets - uniqlo ultralight jacket

Cotopaxi Fuego Hooded Jacket

Price: $230

Weight: 14 oz

Fill weight: N/A

Fill power: 800 fill goose down

Shell material: Ripstop Nylon

This 3-season jacket comes offered in a variety of cool, retro colors, and an updated athletic fit design that provides a good range of motion and breathability. It also has a newly improved, snag-resistant zipper along with an adjustable drawcord hem.

The jacket features cool additions like ultra-soft fabrics, elastic binding (for extra protection against the cold), fleece-lined pockets, water-resistant down, stash and zipper pockets, and a zippered neck that sits comfortably at the jawline—for extra protection. It compacts down into itself by way of a pocket, and the Fuego design is available in a vest, hooded or non-hooded version.

🛒 Available at rei.com. All three options come in men’s and women’s.

ultralight down jackets - uniqlo ultralight jacket

Marmot Ares

Price: $175

Weight: 15.5 oz

Fill weight: N/A

Fill power: 600 fill down

Shell material: Polyester rip-stop

The Marmot Ares is another retro-colored jacket that features modern-day abrasion-resistant fabric. Its down insulation is specially treated so it retains its loft even if getting a bit wet, keeping users continuously warm and comfortable.

The jacket's made with a flexible “angel wing” design which allows for easy, full-range mobility whether hiking, climbing, or skiing. This little design feature also keeps the jacket in place when users raise their arms—a nice touch. There’s a draw-string hem, an internal zippered chest pocket, and zippered external pockets that the jacket packs into. The Ares is a warm, moderately breathable down option that comes in a regular fit.

🛒 Available at amazon.com

ultralight down jackets - uniqlo ultralight jacket

Forclaz Trek 100

Price: $79.99

Weight: 10.2 oz

Fill weight: 3.8 oz, 29.5% (L)

Fill power: 800 fill duck down

Shell material: Nylon

Made for tackling cool weather in the mountains, this versatile well-priced down jacket is a steal. It’s another one that packs into its own pocket and can be smooshed down into the size of a grapefruit. Note it is a bit snug around the chest... kind makes you feel like a fat-guy-in-a-little-coat.

At first glance, the jacket may not appear super “puffy” or “lofty,” especially in the sleeves, but it holds its own in warmth keeping hikers well-insulated down below freezing. The company offers an excellent 1-year, “no questions asked” warranty on all their products and an even longer warranty in case of any manufacturer defects.

🛒 Available at Decathlon. A women’s version is available.

Arcteryx Cerium LT down hoody

Arc'teryx Cerium LT

Price: $349

Weight: 9.9 oz

Fill weight: N/A

Fill power: 850 fill European goose down

Shell material: Arato 10D

This thing is puffy! The Cerium earns praise for its great warmth to weight ratio and its trim, athletic fit. The lightweight coat keeps you warm in mild temperatures and toasty in the winter under a shell. To combat down's vulnerability to wetness, Arcteryx has placed Coreloft synthetic insulation in moisture-prone areas such as the armpits.

The jacket has an impressively minimal and breathable design for the level of heat retention it provides, and its hood is a nice addition for extra warmth. The outer fabric of the jacket is thinner than some, so beware of tearing if worn alone. But overall, this is a great mid-layer piece that’ll have no trouble keeping you warm.

🛒 Available at amazon.com. Also in a women's specific model.

ultralight down jackets - feathered friends eos

Feathered Friends Eos

Price: $309 

Weight: 10.6 oz

Fill weight: 3.7 oz

Fill power: 900+ fill goose down

Shell material: Pertex Quantum brushed nylon with DWR

Cottage manufacturer Feathered Friends is known for its outstanding down quilts, and its down jackets maintain that same standard of excellence. Not skimpy at all, the Eos is filled with a whopping 3.7 ounces of 900 fill goose down. Because of its warmth, the Eos is exceptional as a stand-alone jacket and can be layered when the temperature plummets.

What’s particularly great about this jacket is its carefully crafted “extra’s.” The non-snagging zipper, the durable fabric, the cut, the ideal sleeve length (a common problem on puffy’s), and the relaxed fit. The jacket also comes with an elastic drawcord hem and its own stuff sack.

🛒 Available at featheredfriends.com. Also available in a women's specific model.

ultralight down jackets - uniqlo ultralight jacket

Uniqlo Ultralight Jacket

Price: $59.90

Weight: 8.3 oz

Fill weight: N/A

Fill power: 640+ fill goose down

Shell material: 20D nylon

The Uniqlo deserves mention for its meager price tag. It is warm, has deep pockets, and uses a DWR treated fabric to protect against moisture. To reach this low price point, some features, like an adjustable hood and hem, were not included on this budget jacket.

The jacket runs true to size with paneling along the back of the waist for a more natural, slimming, fit. It’s easy to pack and take on the go with a built-in bag that it compresses into. The Uniqlo is perfect for 3-season wear in temperatures falling between 20-50F, and it’s a great lightweight choice for outdoor adventures, city dwellers, or travel. 

🛒 Available at uniqlo.com. It is available in a women's version.

Wash & Care

Here are 8 tips for maintaining the loft and insulation of your down jacket:

1. Wash Frequency: Once a season is a good rule of thumb, although washing frequency varies by user.

2. Before Washing: Before washing, always fasten buttons, snaps, and close any zippers. Then, before doing anything else, check the manufacturer’s instructions (either on the tag or on the company’s website.) Different jackets have different cleaning rules!

3. Detergent: It’s best to use a special down detergent like Gear Aid ReviveX, Nikwax, or Granger down wash as these are specifically designed to revitalize water resistance and clean without harming loft.

4. Removing Stains: For stains, use a little mild soap or water and dab the area with a sponge or dishcloth. To wash the entire garment, you can hand wash it or use a front-load machine. Just don’t use a top-loader, their agitators are too harsh.

5. Drying: It’s okay to throw down in the dryer, just use the lowest heat setting, toss a tennis ball or two in to revitalize the downs fluff, and check on the jacket every 20-30 minutes to ensure it doesn’t overheat.

6. Storage: Just how you shouldn’t store a sleeping bag scrunched up in a stuff sack, the same rule applies with a down jacket. This causes the loft to clump together which leads to spotty insulation and cold spots. Instead, leave the jacket hanging and let it breathe while at home.

7. Rain: Down jackets can be worn in the rain if they’re underneath a shell. It’s best to never directly expose them to prolonged moisture as it can cause the down to clump and lose its warmth. Keep this in mind for humid hikes and body sweat, too.

8. Tears: As warm as down jackets are, they’re just as delicate. They aren’t designed to be worn through brush or trees. They’re best for at night around camp where there’s less chance of coming into contact with prickly objects. But in case of a tear, there’s a specific nylon repair tape that’ll patch things up. A strip of duct tape can work too.

decathlon down jacket Forclaz down jacket (by Decathlon)

Where Does Down Come From?

Minor sources of down come from Canada, Hungary, Greenland, and Iceland, while the largest producer of down in the world is China, accounting for over 80%.

Hungarian Down: The title for “the best down” belongs to Hungary, as it’s the largest producer of the highest-quality goose down in the world.

What makes Hungarian down so great? Well, Hungarian geese have adapted over thousands of years to the country’s harsh climate and extensively cold winters. In doing so, their feathers now have impeccable insulation qualities while still being luxuriously fine and soft. Another fun fact about Hungary is that the country’s geese farmers are known for their sustainability efforts and ethical treatment towards the birds. 

Eiderdown Down: Another big down producer, Iceland manufactures over 80% of a rare quality down called “Eiderdown,” named after the large Eider duck that nests in both Iceland and Canada. This duck down is durable, breathable, and ultra-soft while its naturally high density provides excellent insulation, making it one of the top-down options in the world.

Kelly Hodgkins photo

About Kelly Hodgkins

By Kelly Hodgkins: Kelly is a full-time backpacking guru. She can be found on New Hampshire and Maine trails, leading group backpacking trips, trail running or alpine skiing.

About Greenbelly

After thru-hiking the Appalachian Trail, Chris Cage created Greenbelly to provide fast, filling and balanced meals to backpackers. Chris also wrote How to Hike the Appalachian Trail.

Affiliate disclosure: We aim to provide honest information to our readers. We do not do sponsored or paid posts. In exchange for referring sales, we may receive a small commission through affiliate links. This post may contain affiliate links. This comes at no extra cost to you.
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