Is ASOS sustainable? We checked 11,579 products.

On fabric composition — the one factor we can measure — ASOS averages 37.2% natural fibre across 11,579 products, ranking #46 of 55 brands we track. That's toward the bottom. Fabric data can't speak to labor practices, emissions, or water use, so treat this as one input, not a verdict.

We measure fabric, not business models — so we can't classify ASOS as fast fashion or not. What the data shows: 46.2% of their products are polyester-heavy and 27% are nearly all-natural (95%+ natural fibre). Heavy synthetic reliance often correlates with fast-fashion production, but it isn't proof either way.

Fabric composition is a reasonable quality proxy: natural fibres generally breathe better, last longer, and shed fewer microplastics. ASOS averages 37.2% natural fibre, which is below average. Individual items vary widely, so check the composition label on each piece.

That depends on what you're buying. 27% of ASOS's catalog is nearly all-natural, so good pieces exist even though the average leans synthetic. Use the Fibr extension to check fabric composition on individual items while you shop — it varies more within a brand than between brands.

62.3% of ASOS products are majority synthetic (less than 50% natural fibre by weighted content). The catalog as a whole averages 37.2% natural fibre, so it leans synthetic.

Yes — average natural fibre content has gone up from 35.1% (May 2026) to 37.2% today, based on our point-in-time snapshots of their catalog.