On October 3, 2017, Guests began to be removed from Roblox.  Nightgaladeld stated that the reason was to increase the number of users in Roblox. Despite the removal, guest toys are still being sold in stores. Now, unregistered users can still access the website, but cannot play games, change an avatar, leave comments, create things, or make forum posts. Some players liked this idea, However, most players were angry at Roblox and started protesting in places like the Roblox forum to bring them back.
There have been numerous sightings of guests in games even after the removal, mostly from people using third-party tools to join games as guests or using mobile as stated above.
On November 4th, 2017, ROBLOX re-added guests by mistake, this change lasted for a day before being reverted.
As of the removal, Guests are only able to play games officially via the ROBLOX mobile device app.