Down vs Synthetic Jackets: How to Choose the Best Insulated Jacket for the Outdoors

Down vs synthetic is one of the most common questions our in-store experts get asked, and for good reason. Down insulation gives you the most warmth for the least weight and packs the smallest, so it suits cold, dry conditions and trips where every gram counts. Synthetic insulation keeps you warm when it gets damp, dries faster and is easier to wash, which makes it the safer pick for wet UK weather and hard-working days on the hill. If you want some of both, a hybrid jacket puts down where you need warmth and synthetic where moisture builds up.

But there is a lot more to down and synthetic jackets than just that brief explanation. In order to help you make an educated decision before you before, this insulated jacket buying guide compares down and synthetic side by side, explains when each one makes sense, and covers fill power, care and the features worth paying for.

What is an Insulated Jacket and How do they Work?

Let’s start with one of the most common questions we get asked, how exactly do these jackets keep you warm?

Insulated jackets can be split into two categories based on their filling material; they are either made from down insulation or synthetic insulation. One isn’t necessarily better than the other as they are both superb at keeping you warm and have varying performance pros & cons. Ultimately, it depends on what you are going to use the jacket for.

Down Jackets

Down jackets are made using a fine layer of fluffy feathers from ducks or geese to keep you warm. They are great at retaining heat as the loft from the feathers trap warm air in tiny pockets and spread it across your body. The main attraction of a down jacket is the weight to warmth ratio. This means that down jackets can remain lightweight as they require less stuffing to achieve the same warmth that you get from synthetic down.

Down is the best choice for cold, dry conditions, alpine trips and ski holidays, travel, and any time you want a warm layer that packs down small in your rucksack. It also works well as an extra layer to throw on at summit stops or around camp. You’ll find a wide range of styles and fill weights in our men’s down jackets and women’s down jackets.

The drawback of down insulation is that it struggles to perform when wet. If you were to get caught in a sudden shower, or any moisture gets onto the insulation, it will clump together resulting in all that retained heat disappearing and potentially ruining the jacket. To combat this, some down jackets use “hydrophobic down” which has been treated to handle moisture better. However, we still don’t recommend getting caught in the rain with any down jacket unless it is specified as waterproof or you have an extra waterproof shell to wear over the top. Our waterproof jacket buying guide can help you choose one.

Synthetic Jackets

Synthetic jackets use man-made fibres, typically polyester, designed to mimic the loft and warmth of down while performing better in moisture. They are also more breathable and usually cost less. The trade-off is weight: synthetic insulation has a lower warmth-to-weight ratio than down, so a synthetic jacket needs more fill to reach the same warmth, making it heavier and bulkier.

Synthetic jackets are a good choice for higher exertion activities, such as climbing, ski touring or fast hillwalking, where you'll sweat into your layers and the extra breathability helps. Another important benefit is the ability to handle moisture. A synthetic jacket keeps insulating even when wet, and it dries and re-lofts quicker, which makes it the safer pick for damp UK weather or as an outer layer when you might get caught in drizzle. You'll find synthetic options alongside down in our insulated jackets range.

Hybrid Jackets

Some jackets combine both. Hybrid jackets use down in the torso, where you need the most warmth, and synthetic insulation in moisture-prone areas such as the hood, shoulders and underarms. They're a good middle ground if you want the warmth and packability of down with better protection in damp conditions. Other hybrid jackets pair synthetic insulation on the body with stretchy fleece panels on the arms and sides for breathability and movement.

Down vs Synthetic at a Glance

How Long Will an Insulated Jacket Last? Durability, Care and Value

With good care, a down jacket can keep its loft and warmth for many years. Synthetic insulation is tougher day to day but slowly loses loft as it’s compressed, washed and worn, so it usually needs replacing sooner.

In terms of cost over time synthetic usually costs less to buy, but down can work out better value over the years if it outlasts a synthetic jacket. To compare the two, think about cost per year of use rather than the price tag alone.

Caring for Your Insulated Jacket

Down needs more care. Wash it only when needed with a down-specific cleaner on a cool, gentle cycle, then tumble dry on a low heat with a couple of clean tennis balls to break up any clumps until it's completely dry. Synthetic jackets are much easier: they wash well, dry quickly and don't clump. For both, store your jacket uncompressed rather than in its stuff sack to help it keep its loft.

Check out our care and repair guide on how to look after your outdoor kit for more detailed information on looking after your insulated jacket.

Features of an Insulated Jacket

Once you have figured out whether you want a down or synthetic jacket, you can have a look at some features you may want on your jacket.

Fill power: fill power is the rating used to represent the quality of down in a jacket. After a standardised lab test, the fill power is calculated by how many cubic inches one ounce of down fills. A higher fill-power number means the down takes up more space in the jacket, resulting in more air being trapped. A higher fill power number doesn't necessarily mean the jacket is warmer, as warmth also depends on how much down is used. Synthetic jackets don't have a fill power rating and usually list the weight of insulation in grams instead.

Weight: depending on your needs, you may be looking for an insulated jacket for everyday use when the autumn and winter weather arrives. You may also be planning a hiking trip where you carry everything on your back, in which case down gives you the most warmth for the least weight. Naturally, lighter, space-saving jackets can cost more money, which is something you may want to include in your decision-making process.

Hoods: again, the decision of a hood is up to personal preference. Hoods can be great as they add extra warmth and keep the wind out. On the other hand, you may like to use your jacket as a midlayer, resulting in the extra bulk of a hood being too irritating.

Pockets: some jackets come without any pockets and some have extra internal zippered pockets, how important are these features to you?

Insulated Waterproofs

Feeling cold isn't fun but being wet and cold is even worse. Insulated jackets are great at keeping your core temperature up; however, they aren't designed to protect you from the rain. A happy medium is an insulated waterproof, made just like an insulated jacket but with a waterproof shell outer. Some can be found as "3 in 1 jackets", and come in both men's and women's where the internal insulated jacket can be zipped in or out as part of a layering system. Other insulated waterproofs are just heavier and warmer versions of a traditional waterproof jacket. If you are out with the dog or exploring some winter walking routes, an insulated waterproof can be a great idea for when the weather is being unpredictable.

Stylish and Warm Jackets

If you aren't in the market for the latest piece of hi-tech equipment, that doesn't mean you have to settle for less when it comes to a warm jacket. There are plenty of warm and stylish jackets that are perfect for everyday activities. The same design principles have been used by brands to create longer length men's parkas, women's parkas, anoraks and casual jackets that will look great and keep you warm. Whether you are walking round your local park or just nipping to the shop, these jackets will keep you looking great and feeling protected. Of course, younger explorers can find themselves a kids' insulated jacket too.

What’s New in Insulated Jackets?

Insulated jackets have improved a lot in recent seasons, and not only in warmth.

• PFC-free finishes: most brands have replaced “forever chemical” water repellents with PFC-free alternatives. They still shed light rain but need reproofing more often.
• Recycled and responsible fills: recycled polyester insulation and Responsible Down Standard (RDS) certified down are now common.
• Better synthetics: the best synthetic fills now match lower-grade down for warmth while still performing in the wet.
• Smarter construction: body mapping, stretch panels and box-wall baffles put warmth where you need it and cut cold spots.

Want to make a lower-impact choice? Find out more about Tiso’s approach on our Material Impact page.

Tiso Expert Advice Before You Buy

Now you know the main things to consider when comparing down vs synthetic jackets for the outdoors. In summary, choose down for cold, dry conditions when you want the most warmth for the least weight and pack size. Choose synthetic for damp weather, high-exertion activities and low-maintenance everyday use. If you want a bit of both in one jacket, consider a hybrid.

Still unsure? Think about what your trip entails: what will the weather conditions be? How much weight do you want to carry? How much do you want to spend? Once you have found the right insulated jacket for you, it's time to get out and explore. Our team’s quick video shows you how to pick a down jacket, and whether synthetic might suit you better.

The benefit of buying from an outdoor specialist like Tiso is that you can pop into your nearest store for expert advice. Our staff can help you compare down, synthetic and hybrid jackets side by side, check the fit over the layers you normally wear, and talk through where and how you’ll use your jacket. They’ll help you find the best choice for your needs and budget.