Should I get the 2-inch or 3-inch version?

The 2-inch adds moderate pressure relief and changes the mattress feel less. The 3-inch adds more cushioning and softness, but it raises the bed height more and may make fitted sheets tight.

Will it make a firm mattress softer?

Yes. It is designed to add responsive foam comfort over a mattress that feels too firm. It softens the surface but does not change the mattress's underlying support.

Casper describes it as breathable, but some owners say it sleeps warmer than their mattress alone. Hot sleepers should weigh that against the added cushioning.

Will it stay in place on the bed?

Some owners report it sliding out of position. A fitted sheet over the topper helps hold it, and a grip pad underneath can reduce shifting.

Can I use it on any mattress?

It lays over an existing mattress, including foam, hybrid and innerspring beds. It is meant to add comfort, not to fix a sagging or worn-out mattress.