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Quantum Circuit Simulator Online

Run quantum circuits in your browser — no installation, no account required. Supports OpenQASM, Qiskit, PennyLane, and Cirq.

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How quantumcomputer.dev compares

Featureqc.devQuirkIBM Quantum
Browser-based
No install needed
Permanent circuit URLs
Framework-agnostic
OpenQASM support
Circuit registry
Fork and remix
Free forever

Try these circuits

Bell State

The simplest entanglement circuit — two qubits, one Hadamard, one CNOT.

Run in Simulator →

Grover's Search

Quadratic speedup for unstructured search. The most famous quantum algorithm.

Run in Simulator →

Quantum Fourier Transform

The quantum analog of the discrete Fourier transform — foundation of Shor's algorithm.

Run in Simulator →

How it works

1

Paste or build your circuit

Use the drag-and-drop editor or paste OpenQASM code directly.

2

Run it in the browser instantly

Statevector simulation up to 20 qubits. See probabilities in real time.

3

Save and share a permanent URL

Every saved circuit gets a citable, forkable URL on the registry.

Features

Drag-and-Drop Gate Palette

Hadamard, Pauli-X/Y/Z, CNOT, Toffoli, Phase, T gates and more. Build circuits visually without writing code.

Up to 20 Qubits

Simulate circuits with up to 20 qubits in-browser using statevector simulation. No cloud account required.

Instant Probability Output

See measurement probabilities in real time as you add gates. Visualize the quantum state with probability bars.

Export to OpenQASM

One-click export to OpenQASM 2.0. Copy to clipboard or download .qasm files for use with IBM Quantum, AWS Braket, or Azure Quantum.

Multi-Framework Code

Get equivalent circuit code in Qiskit, PennyLane, and Cirq. Copy-paste directly into your Python notebooks.

Permanent Circuit URLs

Save circuits with permanent, citable URLs. Fork any public circuit. Every circuit is versioned and downloadable.

AI Circuit Generation

Describe a circuit in plain English and get working OpenQASM. Great for learning and prototyping.

Open in IBM Quantum

Send your circuit directly to IBM Quantum Composer. No account linking — just copy QASM and open in a new tab.

Frequently Asked Questions

What is a quantum circuit simulator?

A quantum circuit simulator is software that models the behavior of a quantum computer on classical hardware. It applies quantum gate operations to simulated qubits and calculates the resulting probability distribution of measurement outcomes.

How many qubits can I simulate?

Our browser-based simulator supports up to 20 qubits using statevector simulation. This runs entirely in your browser — no server calls needed. For larger circuits, export your OpenQASM and run on IBM Quantum or AWS Braket.

Is this simulator free?

Yes. The simulator and playground are completely free. Free accounts can save up to 3 circuits. Pro accounts ($9/month) get unlimited circuits, version history, and more AI generations.

What quantum gates are supported?

We support all standard single-qubit gates (H, X, Y, Z, S, T, Rx, Ry, Rz), two-qubit gates (CNOT, CZ, SWAP), and multi-qubit gates (Toffoli, Fredkin). Custom unitary gates can be defined via OpenQASM.

Can I export my circuits?

Yes. Every circuit can be exported as OpenQASM 2.0, downloaded as a .qasm file, or copied as Qiskit, PennyLane, or Cirq Python code. You can also open circuits directly in IBM Quantum Composer.

What is OpenQASM?

OpenQASM (Open Quantum Assembly Language) is a standard language for describing quantum circuits. It is supported by IBM Quantum, AWS Braket, Google Cirq, and most quantum computing platforms.

Start simulating quantum circuits

Free. No sign-up required. Works in any modern browser.

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