Google Willow vs IBM Heron r2 Specs, Pricing & Performance [2026]
Quick Verdict
Google Willow leads on 2Q gate fidelity (99.88%). IBM Heron r2 offers more physical qubits (156 qubits).
Specification Comparison
| Metric | Google Willow | IBM Heron r2 |
|---|---|---|
| Physical Qubits | 105 | 156 ✓ |
| Technology | Superconducting | Superconducting |
| 2Q Gate Fidelity | 99.88% ✓ | 99.50% |
| 1Q Gate Fidelity | 99.97% | 99.97% |
| Readout Fidelity | 99.90% ✓ | 99.80% |
| Quantum Volume | — | 256 ✓ |
| CLOPS | 100,000 ✓ | 5,000 |
| T1 (Relaxation) | 100 µs | 300 µs ✓ |
| T2 (Dephasing) | 80 µs | 200 µs ✓ |
| 1Q Gate Time | 25 ns ✓ | 60 ns |
| 2Q Gate Time | 68 ns ✓ | 680 ns |
| Connectivity | Grid (deg 4) | Heavy Hex (deg 3) |
| Max Circuit Depth | 1,000 | 6,000 ✓ |
| Max Shots | 1,000,000 ✓ | 100,000 |
| Dynamic Circuits | No | Yes |
| Error Mitigation | Available | Available |
| Cloud Platforms | 0 platforms | 3 platforms |
Green bold values with a checkmark indicate the better result for each metric.
Pricing Comparison
Example: 10-qubit, 50-depth circuit, 1,000 shots — estimated cost on cheapest platform: Google Willow: N/A vs IBM Heron r2: $8.00
Superconducting Google Willow
Superconducting IBM Heron r2
| Platform | Price | Status |
|---|---|---|
| Best IBM Quantum | $1.60/sec | Available |
| Strangeworks | $1.60/sec | Available |
| qBraid | $1.60/sec | Available |
Use Case Recommendations
Higher 2Q gate fidelity (99.88%) means fewer errors in VQE/UCCSD circuits.
More qubits (156 qubits) allows encoding larger problem instances.
Supports dynamic circuits and mid-circuit measurement required for active error correction.
Frequently Asked Questions
What is the difference between Google Willow and IBM Heron r2?
Google Willow leads on 2Q gate fidelity (99.88%). IBM Heron r2 offers more physical qubits (156 qubits).
Which is better for quantum chemistry, Google Willow or IBM Heron r2?
For quantum chemistry simulations (VQE, UCCSD), Google Willow is preferred due to its higher 2Q gate fidelity (99.88% vs 99.50%). Higher gate fidelity directly reduces circuit error rates in chemistry algorithms.
How do the prices compare between Google Willow and IBM Heron r2?
Google Willow is available from no public cloud access. IBM Heron r2 is available from $1.60/sec on IBM Quantum. Note that pricing models differ — per-shot pricing is directly comparable while AQT and HQC models depend on circuit structure.
Which QPU has better connectivity, Google Willow or IBM Heron r2?
Google Willow uses Grid connectivity (degree 4) while IBM Heron r2 uses Heavy Hex connectivity (degree 3).
What are the coherence times for Google Willow vs IBM Heron r2?
Google Willow: T1=100 µs, T2=80 µs. IBM Heron r2: T1=300 µs, T2=200 µs. IBM Heron r2 has longer coherence times, which generally allows for deeper circuits before errors accumulate.
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