Down vs Synthetic Insulation

Down offers the best warmth-for-weight and packability of any insulation but loses warmth when wet and costs more; synthetic insulation is heavier and bulkier for the same warmth but keeps insulating when damp, dries faster, and is cheaper. The choice comes down to climate, weight priorities, and budget.

Aspect	Down Insulation	Synthetic Insulation
Warmth for weight	Best	Lower (heavier/bulkier)
When wet	Loses most warmth, dries slow	Keeps much warmth, dries fast
Packability	Excellent (compresses small)	Less compressible
Cost & lifespan	Pricier, long-lived if cared for	Cheaper, loses loft sooner
Best for	Dry, cold, weight-conscious trips	Wet conditions, budget, hard use

Choose down if…

You want maximum warmth for minimum weight
Conditions are dry or cold
Packability matters most

Choose synthetic if…

You'll face wet or humid conditions
You want lower cost and easy care
You need warmth that survives soaking

Verdict

Down wins for dry, cold, weight-sensitive trips and packability; synthetic wins for wet climates, hard or sweaty use, and budget. Hydrophobic-treated down narrows the wet-weather gap, but synthetic is still the safest bet when staying dry isn't guaranteed.

Frequently asked questions

Is down or synthetic insulation warmer?

For its weight, down is warmer and more packable than synthetic. But that advantage disappears when down gets wet, since it collapses and stops insulating, while synthetic keeps much of its warmth damp. So down is warmer for the weight in dry conditions; synthetic is more reliably warm when wet.

Which is better for wet climates?

Synthetic insulation, because it retains warmth when damp and dries quickly, making it more dependable in rainy, humid, or high-sweat conditions. Hydrophobic-treated down helps down resist moisture, but for guaranteed wet weather, synthetic remains the safer choice.

Is down worth the extra cost?

If you prioritize the lightest, most packable warmth for dry, cold trips and will care for it, yes — quality down lasts a long time and is unmatched for warmth-to-weight. If you're on a budget, face wet conditions, or want low-maintenance gear, synthetic offers better value and reliability.