fascinating spintronic effects are spinorbit torque (SOT) [10] and spin Hall magnetoresistance (SMR) [11] in ferromagnet (FM)/heavy metal (HM) bilayers. Taking advantage of these intriguing effects, recently we have demonstrated an AMR/ SMR sensor (hereafter we call it SMR sensor considering the fact that SMR is dominant) with the SOT effective field as the built-in linearization mechanism, [12,13] which effectively replaces the sophisticated linearization mechanism employed in conventional MR sensors. [14] However, as the sensors were driven by DC current, we still faced the same issues as commercial AMR sensors, that is, DC offset and domain motion induced noise. Here, we demonstrate that, by introducing AC excitation, we achieved an all-in-one magnetic sensor which embodies multiple functions of AC excitation, domain stabilization, rectification detection, and DC offset cancellation, and importantly, all these features are realized in a simplest possible structure which consists of only an ultrathin NiFe/Pt bilayer. Such kind of integrated AC excitation and rectification are not possible in conventional AMR sensors. The sensors are essentially free of DC offset with negligible hysteresis and low noise (with a detectivity of 1 nT Hz −1/2 at 1 Hz). Through a few proof-ofconcept experiments, we show that these sensors promise great potential in a variety of low-field sensing applications including navigation, angle detection, and wearable electronics.When a charge current passes through a ferromagnet (FM)/ heavy metal (HM) bilayer, it brings about two novel spintronic effects, namely, the SOT [10] and SMR. [11] Both SOT and SMR share the same origin, i.e., the spin current generated in the HM layer by the spin Hall effect (SHE). [15][16][17] The spin current is transverse to the charge current and therefore causes spin accumulation at both the FM/HM interfaces and side surfaces of HM. The spin accumulation at the interfaces is partially absorbed by the FM layer, resulting in a torque on its magnetization, i.e., the SOT. Although the exact mechanism still remains debatable, both Rashba [18] and SHE [15][16][17] are commonly believed to play a crucial role in giving rise to the SOT in FM/ HM bilayers. There are two types of SOTs, one is field-like (FL) and the other is damping-like (DL); the latter is similar to spin transfer torque. Phenomenologically, the two types of torques can be modelled by