Chunky baffled down jackets or synthetic belay parkas are the most effective layers for cold camps and sub-zero summits.
Up until the last decade, down insulation has ruled this part of the market. The highest quality down has an unrivalled warmth-to-weight ratio that synthetic insulation has historically been unable to match. But developments in synthetic insulation, such as those achieved by PrimaLoft for example, has significantly closed the performance gap to the point where synthetic insulated jackets are a viable alternative to down, with the added benefit of being better value for money too.
We've been putting a range of the best down and synthetic insulated winter jackets to the test to see how they perform. But first, read below to see what features are important in insulated winter jackets.
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The best insulated jackets
Rab Mythic Ultra
Verdict: A highly-technical winter jacket with an amazing warmth-to-weight ratio – but it is pricey.


Rab Mythic Ultra Men's Jacket

Rab Mythic Ultra Women's Jacket
Features 4/5 | Fit 4/5 | Comfort 5/5 | In use 5/5 | Value 4/5
Overall score: 88%
Pros: Amazing warmth-to-weight ratio, supremely warm, highly technical
Cons: Expensive, overkill for milder days, flimsy shell, quite bulky
Billed by Rab as the “ultimate ultralight down jacket for freezing temperatures”, the Mythic Ultra is a very warm and thickly lofted puffy jacket with a technical design. The warmth-to-weight ratio is superb, courtesy of the 240g of premium 900 fill power down. Meanwhile, the TILT inner – Rab’s heat reflective technology – improves thermal efficiency further. Yet despite all of this plush insulation, the jacket somehow isn’t too boxy or chunky. Instead, it has an athletic and technical feel.
The Pertex Quantum outer is soft, windproof and ultralight, but the 10-denier material does feel rather thin and flimsy. First-rate features include a nicely shaped adjustable hood with small peak; adjustable waist hem with dropped cut for good coverage over the groin and backside; one external chest pocket; two hand-warmer pockets; and elasticated wrist cuffs for sealing out the cold.
In terms of baffle construction, stitch-through baffles on the arms and hood give better mobility. However, offset boxwall baffles around the core encourage the down to fully loft and spread evenly, thus maximising heat trapping. The jacket is too warm for milder conditions and too thick for layering, but for wintry days it is a super-cosy and high-quality jacket with uncompromising performance.
Sizes men’s S-XXL; women’s 8-16 | Weight 487g (men’s medium) | Insulation Nikwax hydrophobic European goose down (900 fill power) | Materials 10D recycled Pertex Quantum nylon ripstop with PFC-free DWR, recycled polyamide lining | Sustainability RDS-certified down with PFC-free DWR, recycled outer with PFC-free DWR, recycled lining, Rab certified climate neutral and a Fair Wear Foundation leader
Keela Belay Smock
Verdict: A smock-style synthetic jacket with a unique and no-nonsense approach, at a bargain price – but it has some big flaws.


Keela Belay Smock
Features 3/5 | Fit 3/5 | Comfort 4/5 | In use 4/5 | Value 5/5
Overall score: 76%
Pros: Superb value for money, no-nonsense approach, huge vents, PrimaLoft Gold
Cons: Hood not insulated, very baggy, zipper not full-length, heavy
This jacket has big pros and big cons, and therefore will probably polarise opinion. Let’s start with the positives.
It’s superb value for money – a fraction of the price of the premium jackets in this roundup – and the traditional belay jacket design puts functionality above style. Humongous two-way vents at both sides and a baggy fit ensure excellent breathability when require. The sheet-style PrimaLoft Gold synthetic insulation delivers a solid heat boost and retains its warmth when wet.
The outer is water-resistant and windproof, featuring include a basic hood, chunky Velcro wrist cuffs, cinchable collar, Velcro-adjustable waist, two zippered handwarmer pockets and a large chest pocket. All of this adds up to a simple, no-nonsense jacket that works far better out on the hill than initial impressions may suggest.
There are negatives though. The inconvenient over-the-head design may be a deal-breaker for many hillwalkers, the hood is flimsy and not insulated, the Velcro waist adjustment system doesn’t work too well, and the fleece-lined pockets don’t provide any warmth for the outside of your hands. For some, the fit will be excessively baggy too. But at this price it’s difficult to complain.
Sizes men’s XXS-XXL; women’s n/a | Weight 660g (men’s small) | Insulation PrimaLoft Gold synthetic insulation (133g/m2) | Materials Not stated | Sustainability No specific reference
Mountain Equipment Shelterstone
Verdict: A well-designed, fully featured, belay-style jacket with synthetic insulation – but it won’t suit everyone.


Mountain Equipment Women's Shelterstone Jacket

Mountain Equipment Shelterstone Men's Jacket
Features 4/5 | Fit 4/5 | Comfort 4/5 | In use 5/5 | Value 4/5
Overall score: 84%
Pros: Versatile, fully-featured, technical design, well-priced
Cons: Flimsy hood peak, quite heavy
Mountain Equipment’s Shelterstone is the most technical and high-performing synthetic jacket in our round-up. It has a better and more athletic cut than the baggy Keela and Páramo offerings. In addition, it feels slightly more high-end than the Berghaus Affine.
Combining 100% recycled Polarloft synthetic insulation with a weather-resistant shell, it works well as an outer layer in the belay jacket mould. Yet the sheet style insulation – flat, wadded insulation – works well as a mid layer too.
The Drilite Loft 40-denier outer has a PFC-free DWR coating, is windproof and feels reassuringly sturdy. The all-round design is very protective. A full-length, two-way zipper has an internal baffle, zipper garage and press-stud closure at the base. The insulated hood has front and rear toggles for a fine-tuned fit – although the hood’s wired peak is a little flimsy.
Other features include four pockets (one external chest, two handwarmer and one internal mesh), adjustable waist, elasticated and Velcro wrist cuffs, articulated sleeves and a 100% recycled polyamide inner. The price is competitive, and the warmth level is adequate for most UK winter conditions.
Sizes men’s S-XXL; women’s 8-16 | Weight 604g (men’s medium) | Insulation 100% recycled Polarloft synthetic insulation (115g/m2) | Materials 40D Drilite Loft outer | Sustainability bluesign-approved outer with PFC-free DWR, recycled inner, Mountain Equipment a Fair Wear Foundation leader
Black Diamond Vision Down Parka
Verdict: A mega thick, super-lofty, ultrawarm puffy jacket with a premium design and nice features – but it’s quite heavy and bulky.


Black Diamond Vision Down Parka Men's

Black Diamond Vision Down Parka Women's
Features 4/5 | Fit 4/5 | Comfort 5/5 | In use 4/5 | Value 4/5
Overall score: 84%
Pros: Exceptionally warm, excellent hood and collar, superb coverage
Cons: Very expensive, bulky, can’t be used underneath a hard shell
On bitterly cold days, this jacket will be your haven from the elements. It is opulently thick and very toasty, with large chunky baffles positively bursting full of lofty down.
With an 800 fill power and 210g fill weight, the Allied HyperDry goose down delivers a superb warmth boost, and resists moisture to retain performance even when damp.
The build quality is high and there are loads of first-rate features. Our favourites are the humongous collar and hood, which protect your head faultlessly, and the long cut which extends warmth over the backside and groin. The outer shell is a 20-denier Japanese nylon designed to be ultralight yet ‘tough as nails’, as Black Diamond put it. We’d suggest it feels stronger than Rab’s 10-denier outer.
The fit is ‘relaxed’ rather than athletic, and you also get single pull cord adjustment of the waist hem and hood; oversized hand, chest and internal drop pockets; a two-way front zipper with internal baffle and press stud button; and lightweight stretch cuff gaiters at the wrists, rather than Velcro.
It’s expensive and way too thick for layering, but if warmth is what you’re after, this is the toastiest jacket here.
Sizes men’s S-XL; women’s XS-XL | Weight 600g (men’s medium) | Insulation Allied HyperDry 90/10 goose down with DWR treatment (800 fill power) | Materials 20D nylon ripstop outer with DWR, 20D nylon lining with DWR | Sustainability RDS-certified down with PFC-free hydrophobic treatment
Berghaus Affine
Verdict: Lightweight with a slim fit, this synthetic jacket is ideal for long active days – but some may require more warmth.


Berghaus Affine Men's

Berghaus Affine Women's
Features 4/5 | Fit 4/5 | Comfort 4/5 | In use 4/5 | Value 4/5
Overall score: 80%
Pros: Fair price, lightweight, athletic fit, good for layering
Cons: Not the warmest, short cut (no coverage over backside), wrist cuffs not adjustable
The Berghaus Affine is a lighter jacket with a more athletic cut, which can be worn all day without the risk of overheating. Consequently, it’s not as warm as thicker jackets, and the high cut mean’s there’s no thermal coverage below the waist. But it does work far better in a layering system and it’s well-suited for active use. It’ll feel far more comfortable during a steep ascent than the super-thick Rab or Black Diamond jackets, for example.
This jacket is ‘body-mapped’ with zones of different grades of synthetic insulation: 100% recycled 150g/m2 Hydroloft in the main body, 60g/m2 in the hood, shoulders, side and lower body, 40g/m2 in the pocket area. You get warmth where you need it most. Yet this jacket is mostly about breathability, lightness, stretch and freedom of movement – areas it excels in. The wrist cuffs are elasticated rather than utilising Velcro and the hood is warm and adjustable. However, the collar sits low on the chin (for us at least), somewhat exposing your face to the elements.
Features include a full-length zipper (not two-way), two handwarmer pockets, two oddly shaped long and thin internal stuff pockets, fleece-lined chin guard and adjustable waist. The price point is competitive too.
Sizes men’s XS-XXXL; women’s 8-20 | Weight 429g (men’s small) | Insulation 100% recycled Hydroloft synthetic insulation (150g/m2, 60g/m2 and 40g/m2) | Materials Polyamide outer, polyester lining and trim | Sustainability PFC-free, recycled insulation, main fabrics bluesign-approved
Arc’teryx Cerium LT Hoody
Verdict: Super lightweight, comfy and well-designed with a slim-fitting cut, it’s excellent for ultralight enthusiasts – but many will need more warmth.


Arc’teryx Cerium LT Hoody Women's

Arc’teryx Cerium LT Hoody Men's
Features 4/5 | Fit 4/5 | Comfort 4/5 | In use 4/5 | Value 4/5
Overall score: 80%
Pros: Ultralight, superb warmth-to weight, high quality down, excellent fit
Cons: Expensive, too light & thin for full winter, zipper feels flimsy, oddly-shaped hood
This minimalist jacket delivers an excellent warmth-to-weight ratio. Premium 850 fill power goose down combined with Coreloft synthetic insulation in moisture-prone areas are to thank for that. It's a hybrid build Arc’teryx call ‘down composite mapping’.
At just 299g (men’s small), it’s exceptionally light – arguably too light and thin for the coldest of winter days. But for some this will be a positive selling point. If packability, low weight, and the ability to be worn all-day for active pursuits are your top priorities, this jacket hits the brief perfectly. The construction has a streamlined cut that moulds to the body nicely.
Features include a wind-resistant Arato 10 nylon shell with DWR-coating, an adjustable and insulated hood, twin waist hem drawcords, smooth-lined collar, elasticated cuffs, two zippered pockets, internal security pocket and separate stuffsack. To save weight, there is neither a zipper stormflap nor Velcro in the wrist cuffs. Additionally, the relatively high cut provides minimal coverage over the backside.
Sizes men’s s-XX; women’s 8-16 | Weight 487g (men’s medium) | Insulation Nikwax hydrophobic European goose down (900 fill power) | Materials Nylon outer | Sustainability RDS-certified down, bluesign-approved synthetic insulation
Salewa Ortles Medium 2 Down Jacket
Verdict: A baffled down jacket with an athletic and alpine fit that works well for use during intense exercise – but it’s pricey for 750 fill power.


Salewa Ortles Medium 2 Down Jacket Men's

Salewa Ortles Medium 2 Down Jacket Women's
Features 4/5 | Fit 4/5 | Comfort 4/5 | In use 4/5 | Value 3/5
Overall score: 76%
Pros: Good features, alpine fit, works well for layering, ideal for active use
Cons: Slightly overpriced, no Velcro on wrist cuffs, tight hood, only 750 fill power
Unlike thicker jackets, which only really function as standalone outers on the coldest days, the Ortles Medium 2 Down is far more versatile. It is streamlined enough to wear all day, including during high-intensity activities, and has a close-to-the-body fit that works well as an insulating mid layer underneath a hard shell. Or as a standalone outer.
It isn’t the warmest jacket though. The duck down has a slightly disappointing 750 fill power and doesn’t loft as other high-end jackets. And the tight-fitting hood probably won’t suit all head shapes.
But the Ortles does have loads of nifty features. The stretchy wrist gaiters (with no Velcro) seal out the cold and feel super snug; the main zipper has a thickly-padded internal stormflap; and the high collar ensures excellent coverage over the chin and mouth. You also get an external chest pocket, two handwarmer pockets, waist hem adjustment, hood adjustment and a stuffsack.
Like the Arc'teryx jacket, the body-mapping construction is a hybrid approach. There're down-filled 3D box chamber baffles around the core and Tirol Wool inserts (60% polyester, 40% virgin wool) at the hood, shoulders and cuffs. This delivers heat retention to different parts of the body.
Sizes men’s S-XL; women’s 6-14 | Weight 492g (men’s small) | Insulation 90/10 white duck down, 750 fill power, plus Tirol Wool inserts (130g/m2) | Materials Nylon ripstop main material, 20D nylon lining | Sustainability RDS-certified down, PFC-free DWR, Salewa a Fair Wear Foundation leader
Páramo Torres Alturo
Verdict: A warm, fully-featured, synthetic jacket with a baggy cut, designed to be used as an outer layer – but it might polarise opinion.


Páramo Torres Alturo Women's

Páramo Torres Alturo Men's
Features 4/5 | Fit 4/5 | Comfort 5/5 | In use 5/5 | Value 4/5
Overall score: 72%
Pros: Fair price, part of Páramo’s ‘ecosystem’ range, 100% recycled insulation
Cons: No venting options, too baggy, excessively heavy
Páramo clothing has a tendency to polarise opinion. The Torres Alturo is therefore likely to be loved and hated in equal measure. The negatives include the baggy and boxy cut, and heavy weight (735g). Furthermore there are no venting options, such as pit zips, meaning overheating is a real risk.
But other hillwalkers will perhaps love the maverick Páramo approach. The Torres Alturo is over-sized because it’s designed to go over your waterproof. This is a strategy that delivers warmth faster without having to faff around removing layers. And it’s heavy because it has a highly protective construction.
The materials used combine a Nikwax Windproof outer (a closely woven microfibre layer) with Nikwax Analogy Insulator insulation (a 100% recycled, water-resistant synthetic fill). It's a partnership that retains body heat effectively, deflects the rain and aids moisture vapour transfer. The end result is a rugged insulator prepared for gnarly mountain conditions.
The inner lining also has a soft and silky feel, while usual features – Velcro wrist cuffs, adjustable hood with wired peak, toggles for waist cinching, multiple pockets and a dropped hem – are all present.
Sizes men’s S-XXL; women’s XS-XL | Weight 735g (men’s medium) | Insulation 100% recycled Nikwax Analogy Insulator synthetic insulation (133g/m2) | Materials Nikwax outer | Sustainability PFC-free DWR, recycled insulation
Rab Infinity Microlight
Verdict: The newest version of a longstanding Trail favourite, this is a warm, cosy and well-cut puffer that won’t collapse into a soggy mess even if you need to stick it on in clag or light drizzle.


Rab Infinity Microlight Down Jacket

Rab Infinity Microlight Women's
If there is such a thing as a modern classic in outdoor kit, Rab’s Microlight jackets have a good claim to the title. We reckon the new Infinity Microlight is probably the best one yet, featuring a Gore-Tex Infinium face fabric and 700 fill power recycled hydrophobic down insulation. It’s a consummate all-rounder for the hills and mountains, being warm, packable, and more weatherproof than most down puffers.
Key features to look for in insulated winter jackets
Baffles and body mapping: Larger baffles (insulation-filled chambers) give more space for insulation to loft, while smaller baffles help to stop the fill from spreading out unevenly. But the new trend is ‘body mapping’, with different materials and insulation grades used across different parts of a jacket. This provides warmth and venting where it’s needed most.
Draught exclusion: Insulated jackets work by trapping warm air inside the jacket, next to your body. If air escapes at weak points – the hem, cuffs or zip – the warmth is lost. Elasticated or Velcro cuffs, hem drawcords and zip baffles help avoid this problem.
Down vs synthetic: Traditional wisdom states that down offers the best warmth-to-weight ratio, but loses loft and performs poorly when wet, while synthetic insulation offers better value for money and retains its properties better when damp, but is heavier and bulkier. This still holds true, yet constant advancements in synthetic fibres have blurred the performance distinctions between the two.
Fill power, fill weight and GSM: Fill power is a measure of the loft or ‘fluffiness’ of the down, and how much air it traps. The higher the fill power, the warmer it’ll be. Fill weight is the amount of down in a jacket in grams, and more grams equals more warmth. Overall warmth is determined by both fill power and fill weight. Synthetic jackets are graded in gsm (grams per square metre). The higher the figure, the thicker, heavier and warmer the insulation.
Fit: A winter jacket should be roomy enough to wear over other layers, though you may still want to be able to fit it under a waterproof shell. Look for snug-fitting cuffs, a zip that goes right up to the chin and an adjustable hem to lock in warmth.
Outer shell: Insulated jackets are never fully waterproof, but many have a water-resistant and windproof outer shell, such as Pertex with a DWR coating. This helps to keep the insulation dry and thus retain its warmth. When it’s torrential, however, you’ll still need a hard shell on top.
Pockets: A variety of pockets will always prove useful out in the hills. Insulated handwarmer pockets keep your hands toasty, particularly if accessible when wearing a hipbelt, while internal pockets are good for stashing valuables and roomier pockets are useful for storing gloves, a hat or a map.
Sustainability and ethics: It’s best practice to ensure any DWR coatings are PFC-free and any goose or duck down adheres to the Responsible Down Standard. For better eco credentials, choose a jacket with recycled materials and/or bluesign-certified. It's also a good idea to check organisations like the Fair Wear Foundation to see if a brand has ethical labour standards.
Weight and packed size: Winter-weight insulated jackets (typically 400g+) are designed for use when static – they’re too warm to wear if you’re on the move. Since they’ll spend a fair bit of time stuffed in your pack, look for a jacket that balances relatively low weight and compressibility with good overall warmth.
Insulated jacket care and cleaning
It'll only need done occasionally, but giving you insulated winter jacket a proper clean helps it remain breathable, keeps the fabrics and insulation in good condition, and maintains its water repellency.
It's an easy process, head to our guide on caring for insulated gear to find out everything you need to know.