Google Quantum AI

Google Quantum AI, part of Alphabet, builds superconducting quantum chips in its own fabrication facility in Santa Barbara, California. Its current processor, Willow, has 105 qubits. Google does not offer public access; Willow is used by its own scientists and a small number of selected outside research groups. Its work centres on surface-code error correction and on carefully chosen physics experiments intended to show tasks classical computers cannot match. In March 2026 it added a neutral-atom hardware programme alongside the superconducting work.

division of Google, part of Alphabet (a publicly listed company) · Based in United States · Since 2013 · Facts checked 27 October 2026

Where it ranks this month

Best place in each race, from QubitBenchmark release 2026-11.1.

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Most accurate#3Willow, 99.67% Error-corrected qubits–No ranked result Most qubits#3Willow, 105 qubits Fastest–No ranked result Use it today–No ranked result

Machines

Machine	Physical qubits	Introduced	How to use it
Willow	105	2024	not publicly available (selected researchers via Google's 2026 Willow Early Access Program and a UK NQCC call)

Qubit counts as the company reports them. Our rankings use QubitBenchmark's checked results instead.

Promised vs delivered

What Google Quantum AI has said it would build, and what happened.

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Milestone	Target	Status	Why we say so
Milestone 1: beyond-classical computation	unclear	Delivered	Google lists Milestone 1 as completed in 2019. Source
Milestone 2: logical qubit prototype (more physical qubits reduce errors)	unclear	Delivered	Google lists Milestone 2 as completed in 2023. Source
Error correction below the surface-code threshold (Willow)	unclear	Delivered	Published in Nature: the logical error rate roughly halved each time the code grew from 3x3 to 5x5 to 7x7 on Willow (announced December 2024). Source
Milestone 3: long-lived logical qubit	no date given	In progress	Google's October 2025 post names the long-lived logical qubit as the next milestone; July 2026 Nature work improved logical-qubit stability but no completion has been announced. Source
Useful, error-corrected quantum computer	2029	On track (company says)	In March 2026 Google said it is 'increasingly confident' that commercially relevant superconducting quantum computers will arrive by the end of this decade. Source
Neutral-atom programme: demonstrate deep circuits with many cycles	no date given	In progress	Announced March 2026 with a hardware team led by Adam Kaufman in Boulder; no results or dates published yet. Source

Recent claims, and how far the evidence has got

Peer-reviewed 'Quantum Echoes' (second-order out-of-time-order correlator measurement on Willow) described as the first verifiable quantum advantage, about 13,000 times faster than estimated classical runtime on Frontier Source · Our Reality Check
Peer-reviewed Reinforcement-learning calibration cut logical error rates by about 20% and improved logical stability on Willow Source
Announced Google expands into neutral-atom quantum computing alongside superconducting qubits Source

In other organisations' rankings

Where Google Quantum AI appears in other published rankings and lists. They don't change ours.

All of them →

The Quantum Index Report 2026, MIT Initiative on the Digital Economy (MIT Sloan), in collaboration with Accenture (2026-10). Transparent, sourced and openly licensed data, but it measures activity (patents, funding, press releases) rather than how well the machines perform.
Comparative Analysis of Contemporary Quantum Computer Processors: Architectures, Performance, and Perspectives, IEEE Access (authors: M. Vukšić, J. Ćelić, A. Cuculić, University of Rijeka) (2026-03-05). Peer-reviewed, but the paper itself says Table 1 is 'a high-level comparative snapshot rather than a definitive ranking'. Its data is already dated, and some milestone dates should be checked against primary sources.
CB Insights ESP matrices: Quantum computer makers (neutral atoms, photonics, silicon qubit, superconducting circuits, trapped ions), CB Insights (2026). Based on market and business signals, not machine performance. Vendors can brief CB Insights, and most placements are hidden behind a subscription.
Quantum Benchmarking Initiative: Stage B Selection, DARPA (US Defense Advanced Research Projects Agency) (2025-11-06). An official list of who advanced, not a ranking; it partly rests on plans and roadmaps, and Stage C has since narrowed it (see darpa-qbi-stage-c-2026).

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Google vs Quantinuum IBM vs Google

Sources

A verifiable quantum advantage / Google hardware is powering quantum breakthroughs, Google (The Keyword), 22 October 2025
A verifiable quantum advantage, Google Research blog, 22 October 2025
Observation of constructive interference at the edge of quantum ergodicity, Nature, 22 October 2025
Meet Willow, our state-of-the-art quantum chip, Google (The Keyword), 9 December 2024
Milestone 2, Google Quantum AI
Building superconducting and neutral atom quantum computers, Google (The Keyword), 24 March 2026
Google Study Shows Quantum Computer Can Learn From Its Own Errors While It Computes, The Quantum Insider, 10 July 2026
Google Opens Early Access to 'Willow' Quantum Processor, Invites Experimental Proposals, The Quantum Insider, 28 March 2026
Google I/O: Google wants to build a practical quantum computer by 2029, The Next Web, 19 May 2021
Google and NASA Launch Quantum Computing AI Lab, MIT Technology Review, 16 May 2013
Google Quantum AI, Wikipedia