Abstract Quantum error correction will be essential for quantum computers to realise their full potential. As quantum computers advance towards demonstrating a universal fault-tolerant logical gate set, implementing scalable and low-latency real-time decoding will be crucial to avoid an exponential slowdown and maintain a fast logical clock rate. Here, we demonstrate low-latency feedback with a scalable FPGA decoder integrated into the control system of a superconducting quantum processor. We perform an 8-qubit stability experiment with up to 25 decoding rounds and a sub-microsecond mean decoding time per round, providing strong evidence that the backlog problem will be avoided when the decoder is operated as a streaming decoder on a superconducting hardware with the strictest speed requirements. We observe logical error suppression as the number of decoding rounds is increased. We also implement and time a fast-feedback experiment demonstrating a decoding response time of 9.6 μs for a total of 9 measurement rounds. Acknowledgements We thank Steve Brierley, Nicolas Didier, Rossy Nguyen, Matthew Reagor, David Rivas, Jake Taylor, Alice Voaden, and Catriona Wright for their support and championing of this project. We thank Maria Maragkou and Luigi Martiradonna for feedback on the manuscript. We thank David Byfield and Mark Turner for advice on implementation and use of analysis tools. Funding L.C., L.S., N.S.B., A.R., J.Mc., J.A.V., A.D.P., A.V.G., J.Ma., K.M.B., T.B., O.B., O.C., G.P.G., H.K., E.M., C.T., S.P., M.B., K.S., N.I.G., G.J., K.J., E.T.C., and A.D.H. declare no relevant funding. Author information Authors and Affiliations Corresponding authors Ethics declarations Competing interests The authors declare no competing interests. Additional information Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Supplementary information Rights and permissions Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution