Compare Quantum SDKs

A vendor-neutral side-by-side of the major software development kits — because the right tool depends on your goal, not on whose brand you saw first.

Qiskit

IBM · Python · open source

Hardware: IBM Quantum (superconducting)

Best for: General-purpose circuits, the largest ecosystem and learning material, real IBM hardware access.

Cirq

Google · Python · open source

Hardware: Google (research) + simulators

Best for: Fine-grained control over gates, timing, and noise; NISQ experiments.

PennyLane

Xanadu · Python · open source

Hardware: Hardware-agnostic (plugins for many backends)

Best for: Quantum machine learning and differentiable/variational circuits; autodiff across backends.

Amazon Braket SDK

AWS · Python · open source

Hardware: IonQ, Rigetti, IQM, QuEra via AWS

Best for: Running the same code across multiple vendors' hardware from one cloud account.

Q# / QDK

Microsoft · Q# (+ Python interop) · open source

Hardware: Azure Quantum providers

Best for: A dedicated quantum language with strong typing; algorithm-focused, resource estimation.

CUDA-Q

NVIDIA · C++ / Python · open source

Hardware: GPU simulation + QPU backends

Best for: GPU-accelerated simulation and hybrid quantum-classical / HPC workloads at scale.

TKET (pytket)

Quantinuum · Python (C++ core) · open source

Hardware: Many backends (compiler/router)

Best for: Best-in-class circuit optimization and qubit routing; retargeting circuits to real device topologies.

Stim

Craig Gidney / Google · Python / C++ · open source

Hardware: Stabilizer simulation only

Best for: Blazing-fast stabilizer + error-correction simulation; the standard tool for QEC research.

Which should a beginner pick?

Start with Qiskit (largest community and learning material) or PennyLane (if you're drawn to machine learning). Both are Python, free, and run on simulators without any hardware account. You can try circuits right now in the Quantum Sandbox — it even exports Qiskit code.