Packages of information, or packets, are used across the internet and in computer networking to communicate between a sender and a receiver. The sizes of packets can vary depending on how much data there is to be sent. When a packet is sent from sender to receiver it can for numerous reasons be dropped, which is reffered to as packet loss. Previous work in this field have investigated if packet size has an effect on packet loss using different protocols, but there is a gap in investigating if packet size has an effect on packet loss in the protocols WebSocket and WebTransport. This thesis aims to fill that gap. This is done with the help of experiments for both WebSocket and WebTransport, where the round trip time for a message sent from a client to a server is measured. Then by increasing the size of the message, thus increasing the size of the packet, it is evaluated if the change in packet size has an effect on the packet loss. The experiments test different levels of packet loss, 10%, 15% and 20% respectively and send messages in the lengths of 1 to 1000 characters long. The produced results suggest that packet size does not affect packet loss in WebSocket and WebTransport most likely due to the fixed packet loss and test environment not benefiting either small or larger packets. Considering these findings, developers using Socket.IO with WebSocket and WebTransport can take the findings of this thesis into account to minimize packet loss when dealing with different packet sizes.