function stopRecording() if (mediaRecorder && mediaRecorder.state !== 'inactive') mediaRecorder.stop(); mediaStream.getTracks().forEach(track => track.stop()); previewVideo.srcObject = null; startBtn.disabled = false; stopBtn.disabled = true;
mediaRecorder.ondataavailable = (event) => if (event.data.size > 0) recordedChunks.push(event.data); ;
const peerConnection = new RTCPeerConnection(); mediaStream.getTracks().forEach(track => peerConnection.addTrack(track, mediaStream); ); // Then send via SDP offer/answer You can overlay drawings or text on the preview <video> using a <canvas> element layered on top. Limitations and Browser Support | Feature / Browser | Chrome | Firefox | Safari | Edge | |------------------|--------|---------|--------|------| | getDisplayMedia() | ✅ | ✅ | ✅ (13+) | ✅ | | System audio capture | ✅ (flag) | ❌ | ❌ | ✅ | | Cursor capture | ✅ | ✅ | ✅ | ✅ | | Recording quality control | Via MediaRecorder | Same | Limited | Same | api grabador de pantalla
const constraints = video: displaySurface: "window" // "browser", "window", or "monitor" ; Instead of recording locally, you can add the MediaStream to an RTCPeerConnection :
startBtn.onclick = async () => try // Request screen capture mediaStream = await navigator.mediaDevices.getDisplayMedia( video: true, audio: true // Captures microphone + system audio (where supported) ); function stopRecording() if (mediaRecorder && mediaRecorder
// Show preview previewVideo.srcObject = mediaStream;
While it has limitations (especially with system audio), it eliminates the need for browser extensions or native plugins for most basic to intermediate screen capture needs. You’ll have a working screen recorder in minutes
: Copy the code above into an .html file, open it locally or via HTTPS, and click “Start Capture”. You’ll have a working screen recorder in minutes. Have you built something with the Screen Capture API? Share your experience in the comments below.