Abstract On-demand qubit-state initialization is a prerequisite for quantum computation. We demonstrate such a protocol in a device consisting of fixed-frequency transmon qubits pair-wise coupled via tunable couplers — an architecture that is also compatible with the surface code. We use tunable couplers to transfer any undesired qubit excitation to the readout resonator of the qubit, from which this excitation decays into the feedline. In total, the combination of multi-level qubit reset, leakage reduction, and coupler reset takes only 88 ns to complete. Our reset scheme is fast, unconditional, and achieves fidelities above 99%, thus enabling fixed-frequency qubit architectures as future implementations of fault-tolerant quantum computers. Similar content being viewed by others Subjects Introduction The capability to reset a qubit to a known state on demand is an essential operation for quantum computation1. Qubit reset is becoming increasingly crucial for speeding up quantum algorithms and calibration, since lifetimes for superconducting qubits have extended to hundreds of microseconds and more2,3,4, such that resetting by simply waiting for the qubit excitation to naturally decay becomes slow5,6. Protocols for qubit reset (that do not just wait for the qubit to decay) can be either conditional or unconditional, depending on whether or not they require knowledge of the qubit state. In conditional reset, the reset operation is conditioned on a previously measured result7: if the qubit is found in the first excited state \(\left\vert \,\text{1}\,\right\rangle\), a π-pulse is applied to drive it back to its ground state \(\left\vert \,\text{0}\,\right\rangle\). The primary limitation for conditional reset is the feedback time of the control electronics, and the success rate of the feedback operation depends on the readout fidelity. In unconditional reset, the excited state of the qubit is depopulated regardless of the initial qubit state5,6,8,9,10,11,12. Existing unconditional reset schemes typically require multiple drive signals, flux-tunable qubits,