Quirk is a simple quantum circuit simulator, intended to help people learn about quantum computing.

If you want to quickly explore the behavior of a small quantum circuit, Quirk is the tool for you. There's no installing or configuring or scripting: just go to algorithmicassertions.com/quirk, drag gates onto the circuit, and the output displays will update in real time.

(If you're still trying to understand what a quantum circuit even is, then I recommend the video series Quantum Computing for the Determined. Quirk assumes you already know background facts like "each wire represents a qubit".)

Defining features:

• Runs in web browsers.
• Drag-and-drop circuit editing.
• Reacts, simulates, and animates in real time.
• Inline displays for conditional and marginal states.
• Bookmarkable circuits.
• Up to 16 qubits.

Notable limitations (a.k.a. future features):

• No user-defined custom gates.
• No recohering of measured qubits.

Try it out:

algorithmicassertions.com/quirk

Quantum teleportation circuit, with Bloch-sphere state displays inserted:

Quantum pigeonhole circuit, showing the toolbox and default after-circuit state displays:

Reacting and animating smoothly while working with ten qubits:

If you want to make changes to Quirk's code, this is how you get the code and turn your changes into working html/javascript.

1. Have git and Node.js installed.

   sudo add-apt-repository universe

   sudo apt-get update

   sudo apt-get install --yes git npm nodejs-legacy

2. Clone the repository.

   git clone https://github.com/Strilanc/Quirk.git

3. Install the dev dependencies.

   cd Quirk

   npm install

4. (Optional) Run the tests.

   npm run test-firefox

5. Build the output files.

   npm run build

6. Confirm the output works by opening out/index.html with a web browser.

   firefox out/index.html

7. Copy out/index.html, out/src.min.js, and out/favicon.ico to wherever you want.