Are mesh or foam office chairs better?

Neither is better outright — they fail differently. Foam compresses permanently and degrades gradually, so comfort declines a little each year. Mesh holds its shape until the weave or its frame gives out. Mesh ventilates better; foam distributes pressure better over long sittings.

Why it happens

A mesh back supports you through tension: an elastomeric polyester or nylon weave stretched across a nylon frame. Because it is tensioned at assembly, you cannot adjust or restore it later. When it goes, it usually goes at the frame or the edge attachment rather than the weave itself.

Foam supports through compression, and the number that matters is density, not thickness. Cold-cure moulded foam around 45–60 kg/m³ holds up for years. Low-density slabstock cut to shape — common in cheap chairs — takes a permanent set within a year or two, which is the body-shaped dip you eventually sit in.

For long sittings, foam spreads pressure over a wider area, which most people find better beyond a couple of hours. In a warm room, mesh is meaningfully cooler. Neither difference is subtle once you have lived with each.