Down vs synthetic duvets: which is best?

Last updated: 7 July 2026

The short answer

Choose down if you want the most warmth for the least weight and a luxurious, lofty feel, and you don't mind paying more or dry-cleaning it. Choose synthetic (microfibre or hollowfibre) if you want something machine-washable, hypoallergenic and easier on the wallet, and you don't mind a bit more weight. Neither is "better" outright, it depends on your budget, allergies and how hot you sleep.

What's the actual difference?

Down and feather are natural fillings from ducks and geese. Down is the soft, fluffy clusters from the bird's underlayer; feather is heavier with quills. Most natural duvets are a down/feather blend, and the higher the down percentage, the lighter and warmer it is.

Synthetic fillings are man-made. Microfibre uses very fine strands to mimic the soft feel of down, while hollowfibre uses thicker, springier hollow strands that trap air. Both are cheaper to make and fully washable.

Warmth and weight

This is where down wins. Down traps far more heat per gram than synthetic, so a down duvet hits a given tog at a fraction of the weight. A 10.5 tog down duvet might weigh a third of a 10.5 tog hollowfibre one and keep you exactly as warm. If you dislike a heavy duvet, down feels weightless by comparison.

The quality measure for down is fill power, how much an ounce of it lofts up. Higher fill power (600-800+) means fluffier, warmer, lighter down, and it's the main reason two down duvets at the same tog can differ so much in price.

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Comfort, breathability and hot sleepers

Down is prized for its soft, cocooning drape. But it can trap heat, so if you sweat at night you might find it stuffy. Natural fillings like wool and silk breathe better and suit hot sleepers, and some microfibre duvets are now engineered for breathability too. If you overheat, weight isn't your enemy. Trapped heat is. So look for breathable fillings whatever the tog.

Allergies and cleaning

This is where synthetic wins. Microfibre and hollowfibre are hypoallergenic and machine-washable, which matters if you have a feather allergy, asthma or hay fever, or you just want to freshen the duvet at home. Down usually needs specialist or dry cleaning, and a good wash is harder to do well. That said, modern down duvets are cleaned to reduce allergens, and a washable duvet protector helps either way.

Price and how long they last

Synthetic duvets are far cheaper up front, often a quarter of the price of good down. But a quality down duvet, cared for, can last a decade or more and keep its loft, whereas cheaper synthetics tend to go flat and lumpy sooner. So the gap narrows over the years. If you want a buy-it-for-life duvet and can afford it, down is the better long-term value; if you'd rather replace more often for less, synthetic makes sense.

Ethics

If you buy down, look for the Responsible Down Standard (RDS) or a similar certification, which means the down is a by-product of the food industry and not from live-plucked or force-fed birds. Vegans and anyone uneasy about animal products will prefer synthetic, which sidesteps the issue entirely.

So which should you buy?

• Buy down if: you want warmth without weight, a premium feel, and a duvet that lasts, and you can dry-clean it.
• Buy synthetic if: you have allergies, want to machine-wash it, sleep with children or pets on the bed, or you're on a budget.
• Consider wool or silk if: you're a hot sleeper who wants natural temperature regulation.

Whichever you choose, get the warmth right first. Use our tog to GSM converter to see what a given tog means in each filling, and to find the tog that suits your room and the way you sleep.