Our pick for best synthetic insulated jacket in 2021 is the Arc’teryx Atom LT Hoody. As we’ll see below, it outperforms many of its competitors in categories like versatility, comfort, durability, compressibility, and warmth-to-weight ratio.
What is Synthetic Insulation?
Synthetic insulation is a catch-all term for any man-made insulating fibre. These fibres are typically produced using some form of polyester or nylon and mimic the properties of natural insulators like down.
This is accomplished by arranging the ultra-fine synthetic filaments in patterns that trap and store heat, while reducing weight. Many outdoor apparel brands use their own proprietary synthetic materials. Others will license or co-create an insulation from third-party companies, like PrimaLoft Inc., an industry leader in microfiber thermal insulation.
The Top Synthetic Insulated Jackets Reviewed
The Top Synthetic Insulated Jackets Reviewed
BEST OVERALL SYNTHETIC JACKET
At just 14.6 oz (415g), the Atom LT Hoody is a lightweight shell. It’s both insulated and versatile, featuring a unique hybrid construction: The front, back, and arms use a Tyono 20-denier material treated with a DWR finish, while the side panels are made of flexible, breathable mesh.
This means the Atom LT optimizes both warmth and breathability, with a build that offers excellent mobility across a wide range of activities. The synthetic insulation is Coreloft Compact 60, which expertly traps heat and retains loft like a champ.
The Atom LT fits trim and sits at hip-length with a slight drop hem. Two zippered hand pockets and one internal zip pocket provide ample storage, while the StormHood, cinchable waist, and elastic cuffs allow you to micro-adjust your comfort.
To learn more, check out our in-depth product review of the Atom LT Hoody.
- Warmth-to-weight ratio
BEST RUNNER-UP SYNTHETIC JACKET:
Our runner-up is the versatile classic that shines in the city and on the trail. The Patagonia Nano Puff jacket is, above all, an excellent bang for your buck and weighs just under 12 oz (337g).
The 20-denier polyester shell is treated with a water-resistant DWR coating, and features a reinforced 22-denier lining. A high collar, elastic cuffs, and cinchable waist trap heat. Two zippered hand pockets offer ample storage, while an inside zip pocket doubles as a stuff sack.
The Nano Puff is insulated with PrimaLoft Gold Insulation Eco, known for its low bulk, high compressibility, and aptitude at retaining heat when wet. It’s made with 55% recycled content—a waste-savings you can feel good about.
- No frills
BEST BUDGET SYNTHETIC JACKET:
You want the best synthetic insulated jacket you can get without breaking the bank? Lucky for you, Columbia has created exactly that with their Snow Country Hooded Jacket. It features two zippered hand pockets, an inside zip pocket, a scuba hood, a chin guard, and an adjustable waist with slight drop tail.
The Snow Country Hooded Jacket performs exceptionally well for its low price tag. That’s because the durable shell is made of 20D ripstop nylon, while the insulation is Columbia’s own Omni-Heat 3D technology. Instead of a down-mimicking synthetic, Omni-Heat is a lightweight, thermal-reflective lining that traps heat and wicks sweat.
- No compression sack
BEST PERFORMANCE SYNTHETIC JACKET:
For serious adventuring, we introduce the Rab Cirrus Flex. The shell and lining are constructed with Atmos ripstop, which is both rugged and flexible, offering you freedom of movement without having to worry about durability. For warmth, the 3M featherless insulation excels in shoulder-season temps. Inside, the synthetic fleece paneling is soft and warm.
The Cirrus Flex has four pockets; its two zippered hand pockets and two drop-in inside pockets offer more storage than many of its competitors. When not in use, an outside pocket doubles as a stuff sack. When the wind and rain start in the middle of a bike trail or big wall, the slim hood fits easily under a helmet.
- High performance
- Soft interior
- Lots of storage
- Reduced breathability
Top Eco Friendly Synthetic Insulated Jacket
While not as compressible as some of the other entries on our list, The North Face ThermoBall Eco Jacket offers all the same advantages you’d expect from a high-quality synthetic jacket. It also looks enviably good and pairs well with your favourite fall wardrobe.
The ThermoBall Eco is an eco-conscious jacket. It features 100% recycled insulation, while the outer shell is made of 100% recycled nylon. You’ll find a cinchable drawstring at the waist, two zippered hand pockets (one which doubles as a stuff sack), and an inside zip pocket. The DWR coating stands up to light rain and snowfall without sacrificing warmth.
- Moderate compressibility
BEST ULTRALIGHT SYNTHETIC JACKET
In the entire Patagonia pantheon, no jacket delivers the same warmth-to-weight ratio as the Micro Puff Hooded Jacket. For serious ultralighters looking for a toasty layer that weighs about as much as a feather—this is it.
At just 9.3 oz (264g), the minimalist Micro Puff is practically weightless. It’s also highly compressible thanks to its PlumaFill insulation and packs small into its pocket. Elastic seams around the hood, waist, and cuffs help trap heat, while the ultralight ripstop Pertex Quantum shell sheds water, stands up to winds, and is abrasion-resistant.
The Micro Puff really is a hallmark of synthetic insulation success. Though the price may appear steep to some, the value is indisputable when compared to down-filled alternatives.
- Warmth-to-weight ratio
BEST SYNTHETIC INSULATED PARKA
The Kanuk Mont-Royal Coat is not your shoulder-season hiking jacket—it’s your polar vortex life saver. The aptly named Mont-Royal coat is built for those harsh Montreal winters and can withstand temperatures as low as -25°C (-13F).
The THERMO+ synthetic insulation is built to maintain maximum loft and wick sweat. The jacket features two zippered hand pockets and one inside zip pocket. The adjustable storm hood and high collar keep biting winds at bay.
This level of craftsmanship and technology does come at a price, however. That said, this is the only jacket you’ll need for decades to come. For even more protection against the elements, check out the Mont-Royal Down Coat with Coyote Fur (women’s; men’s).
- Extremely warm
- Lots of storage
What to look for when buying a synthetic jacket
Do you know the five most important factors to look for when buying a synthetic insulated jacket? Find out below.
Types of Insulators
Independently-owned synthetic companies (like PrimaLoft and Coreloft) often collaborate with outdoor gear brands to create a brand-proprietary insulation. Alternatively, some companies choose to design their own synthetic insulation in-house: Columbia’s Omni-Heat 3D technology and Mountain Hardwear’s Thermal.Q Elite are top-notch examples.
Whatever insulation is used, we recommend doing some research first. Unlike down, synthetics vary considerably, making it impossible to deduce how warm a particular jacket is based on its insulation alone. Short of gambling on a purchase, spend some time reading reviews and comparisons.
Though occasionally applied to synthetics, down insulation is always measured in a standardized metric called fill-power.
To understand how well a jacket traps and stores heat, you must first understand the concept of fill-power, a measure of loft. Low-quality down has a lower fill-power and therefore less loft. Conversely, high-quality down has a higher fill-power and therefore more loft. Looking at the specs of a jacket, you’ll notice its fill-power reported in the format: 600 fill-power, 700 fill-power, 800 fill-power, etc.
The math behind it is actually pretty simple: how much loft is produced by a single ounce of down, as measured in cubic inches? In the case of 700 fill-power, this means that one ounce of down extends through 700 cubic inches of space. Easy, right?
For instance, if you have two jackets with an equal temperature rating, the one with the higher fill-power will be lighter. That’s because its insulation covers a larger area for the same single ounce than does the lower fill-power insulation.
Most synthetic insulated down jackets are water-resistant, meaning the shell is treated with some kind of water-repellent coating. Remember, this doesn’t mean waterproof.
In fact, most synthetic insulated jackets are not waterproof, since they contain materials that trap and store heat. Think about it: if they were as waterproof as a hardshell, you’d very quickly overheat.
To learn more about the difference between hardshells and softshells, check out our piece, Ultralight & Packable: Windbreakers VS. Softshells.
If you only really intend to use your jacket in urban settings, packability isn’t so important. But if you plan on using it for outdoor adventuring or for travel, you should opt for something that packs small. In other words, something highly compressible.
As we saw above, many models can be compressed into their own pocket. Typically, a synthetic jacket with a high warmth-to-weight ratio can be compressed to roughly the size of a 1L Nalgene bottle or less, making it easy to toss into your pack or briefcase.
Synthetic insulated jackets can be used as both an outer layer and a midlayer. When it comes to fit, this means that (1) it shouldn’t be so snug that you’re unable to layer underneath, and (2) the jacket isn’t so bulky that it prevents you from adding layers over top.
Synthetic winter jackets, on the other hand, are strictly used as outer layers. For more information on how they should fit, check out our in-depth guide on how a winter coat should fit.
Common Questions On Synthetic Insulation
What is the warmest synthetic insulation?
Thanks to the metric known as fill-power, any down-insulated garment can be compared to any other down-insulated garment. Not so with synthetics, unfortunately, since manufacturers make and test their products differently.
That said, a good indicator is loft—its fluffiness, so to speak—the heat-retention quality that decreases in efficiency when compressed or saggy. Though rare, some brands will include a jacket's R-value, a standardized measure of a garment’s heat retention capacity.
How long does synthetic insulation last?
What’s really being asked is: how long does synthetic insulation retain its loft? In truth, there’s no concrete or satisfactory answer. A frequent misconception floating around posits that synthetic goes limp within a year. But that’s not true.
As mentioned earlier, synthetic insulation is an umbrella term for any number of man-made fibers. What you should ask yourself is, what kinds of activities do I need it for? The more demanding your lifestyle, the more robust your jacket should be.
Second, the way you store your jackets is a good predictor of its lifespan. Continually storing your jacket in a compression sack will result in a permanent decrease in loft over time. Though down fares better at regaining its loft, you can mitigate this issue by always storing your synthetic jacket on a hanger.
Is Synthetic Better than down?
Compared to down, synthetics are known to retain heat better when wet. They also dry more quickly. But down insulation still fares slightly better when it comes to weight-to-warmth ratio. While synthetics are starting to catch up, this means a synthetic jacket will be a bit heavier than an equivalently warm down jacket.
Then there’s the question of ethics. Sourcing down from geese has long required inhumane and unsustainable practices. Luckily, brands like Patagonia use ethically sourced and traceable down to minimize harm to animals. Their infamous Down Sweater is a perfect case in point.
So are synthetics better than down? While the traditional party line is a resounding no!, modern synthetics have actually come quite a ways. What’s especially nice about synthetics is their lower price-point, despite their ever-increasing quality.
A good rule of thumb is that synthetics fare better in damp and humid conditions like the American Northeast. In drier climates—where your jacket isn’t at risk of staying wet all the time—down might be the better choice.
Now that you’ve read our guide to 2021’s best synthetic insulated jackets, why not start hunting for your own? Remember, when it comes to price-point, ethics, dry time, and retaining heat when wet—synthetic beats down.
We recommend the Arc’teryx Atom LT Hoody as the best overall performer. If you don’t want to break the bank, consider the Columbia Snow Country Hooded Jacket. And hey—if ultralight is your thing, be sure to check out the unbeatable Micro Puff Hoody. Stay toasty, friends!