L2Relay is a novel packet relay protocol for Wi-Fi networks that can improve the performance and extend the range of the network. A device running L2Relay is referred to as a relayer, which overhears the packet transmissions and retransmits a packet on behalf of the Access Point (AP) or the node if no acknowledgement is overheard. L2Relay is ubiquitously compatible with all Wi-Fi devices. L2Relay is designed to be a layer 2 solution that has direct control over many layer 2 functionalities such as carrier sense. Unique problems are solved in the design of L2Relay including link measurement, rate adaptation, and relayer selection. L2Relay was implemented in the OpenFWWF platform and compared against the baseline without a relayer as well as a commercial Wi-Fi range extender. The results show that L2Relay outperforms both compared schemes.