Is contactless cheaper than Oyster in London?

Where they differ

Contactless caps weekly as well as daily, Monday to Sunday, which Oyster does not do unless you load a Travelcard onto it. If you are in London for most of a week, contactless quietly costs less for that reason alone.

Where Oyster still wins

It works if you have no contactless card, it can hold a railcard discount, and it is not tied to a bank account, which matters if you are lending it to someone.

What not to do

Do not tap in with one card and out with another, and do not keep both in the same wallet and tap the wallet. Either gets you charged twice.