This is a selected list of notable massively multiplayer online games which are free-to-play in some form without ever requiring a subscription or other payment. These are commonly MMORPGs or MMOFPSs, but could be of any genre.
These MMOGs provide client software free of charge and allow users to play the game without requiring payment. The games' expenses are typically funded by sponsors or through donations (which have no effect in the game itself).
These MMOGs are free to play. They are funded through advertising, either in-game or through pop-ups.
These MMOGs are free to play, but players may optionally purchase in-game items or currency.
These MMOGs offer optional additional game content through paid subscription, but are otherwise free to play.