This paper presents the design and implementation of the first in-band full-duplex WiFi radios that can simultaneously transmit and receive on the same channel using standard WiFi 802.11ac PHYs. The design uses a single antenna and achieves close to the theoretical doubling of throughput under typical SNR regimes. The key technical contributions include novel analog and digital cancellation techniques that cancel self-interference to the receiver noise floor, ensuring no degradation to the received signal. The authors prototype their design by building analog circuit boards and integrating them with a fully WiFi-PHY compatible software radio implementation. Experiments in a noisy indoor environment demonstrate robust performance, achieving a median throughput gain of 87% with WiFi radios, close to the theoretically expected 2x throughput improvement. The design is wideband, supporting the highest bandwidth and data rates used by the latest 802.11ac PHY in the 2.4GHz spectrum. The analog cancellation circuit uses off-the-shelf components and a novel tuning algorithm to achieve at least 60dB of self-interference cancellation, while the digital cancellation algorithm models linear and non-linear distortions to eliminate any remaining self-interference. The system is evaluated using test equipment from Rohde-Schwarz and commodity WARP radios, showing superior performance compared to prior full-duplex approaches.This paper presents the design and implementation of the first in-band full-duplex WiFi radios that can simultaneously transmit and receive on the same channel using standard WiFi 802.11ac PHYs. The design uses a single antenna and achieves close to the theoretical doubling of throughput under typical SNR regimes. The key technical contributions include novel analog and digital cancellation techniques that cancel self-interference to the receiver noise floor, ensuring no degradation to the received signal. The authors prototype their design by building analog circuit boards and integrating them with a fully WiFi-PHY compatible software radio implementation. Experiments in a noisy indoor environment demonstrate robust performance, achieving a median throughput gain of 87% with WiFi radios, close to the theoretically expected 2x throughput improvement. The design is wideband, supporting the highest bandwidth and data rates used by the latest 802.11ac PHY in the 2.4GHz spectrum. The analog cancellation circuit uses off-the-shelf components and a novel tuning algorithm to achieve at least 60dB of self-interference cancellation, while the digital cancellation algorithm models linear and non-linear distortions to eliminate any remaining self-interference. The system is evaluated using test equipment from Rohde-Schwarz and commodity WARP radios, showing superior performance compared to prior full-duplex approaches.