Screen Capture API

The Screen Capture API, as the name suggests, allows you to capture the contents of a screen, making the process of building a screen recorder a piece of cake.

You need a video element to display the captured screen. The start button will start the screen capture.

<video id="preview" autoplay>
  Your browser doesn't support HTML5.
</video>
<button id="start" class="btn">Start</button>

const previewElem = document.getElementById("preview");
const startBtn = document.getElementById("start");

async function startRecording() {
  previewElem.srcObject =
    await navigator.mediaDevices.getDisplayMedia({
      video: true,
      audio: true,
    });
}

startBtn.addEventListener("click", startRecording);