Whether you're using it as your main warm layer in spring, summer, or autumn, or as part of a layering system in colder winter weather, a lightweight down jacket is a highly versatile piece of insulation. Offering unrivalled warmth for their low weight and easy packability, thinner down jackets can be handy in pretty much any outdoor setting, from UK cragging to summer in the Alps, ultralight backpacking to year-round hillwalking. You probably wear yours to work, too.

In this comparative review, lightweight down jackets from seven leading brands go head to head. 

Some things we've looked out for:

Fill power: A higher fill power means that a given weight of down occupies more volume, and thus insulates more effectively. Higher fill power down will be warmer for a given weight, but with less 'roughage' than down of a lower fill power it does need to be treated with some care if it's going to last.

Fill weight: All else being equal (it rarely is), the more fill you put in a jacket, the warmer it'll be.

Water resistant-treatment: Treated down is increasingly common, and for UK use it's worth seeking out since it allows the down to maintain its loft (ie. go on working to insulate) for longer in damp conditions. We've considered it a plus point in this review.

Ethics: The ethics of down production are an increasing concern for both brands and consumers. Many (but not all) manufacturers now use down certified by the Responsible Down Standard, which encourages a decent standard of animal welfare by prohibiting the worst practises of the industry, such as force feeding and live plucking, and by establishing an audit trail from farm to finished product. Where a brand has used more ethical down, we've noted it in the review.