Screen Recorder records a screen, a window or a tab that the browser lets you pick. The page is built on getDisplayMedia + MediaRecorder, offers 30 or 60 fps, can request system audio and can open the microphone as well; when both sound sources are available they are mixed locally into one track through AudioContext.

The result is a WebM, encoded as VP9+Opus first, then VP8+Opus, then whatever WebM codec the browser defaults to. ffmpeg.wasm is not used while recording; it is loaded only when you click “Convert to MP4 (send to the audio/video workbench)”.

1. 01Set the options— before recording, choose 30 or 60 fps and decide whether to request “System audio” and “Microphone”.
2. 02Start recording— click the button and pick a screen, window or tab in the browser's share dialog; for system audio you also have to allow audio sharing in that dialog.
3. 03Control the recording— pause, resume or stop; if you press “Stop sharing” in the browser's own bar, the page stops MediaRecorder as well.
4. 04Save the result— after stopping, preview the WebM locally and download it; for MP4, click “Convert to MP4” to send the result to the audio/video workbench.

Platform support

— it depends on getDisplayMedia and works on common desktop Chrome / Edge / Firefox builds; mobile browsers generally do not support it, and the page shows a not-supported message.

System audio

— whether it is captured depends on the browser, the operating system and what you allow in the share dialog; the code notes explicitly that Firefox does not support system audio.

Frame rate is a request

— 30/60 fps is the ideal request on the shared track; the real rate still depends on the system and the shared content.

Output format

— the direct result is WebM only; MP4 is not a recording codec here but a separate ffmpeg conversion of the finished WebM.

What it does not do

— no region cropping, no camera picture-in-picture and no post-recording editing; download the file or send it to the matching audio/video tool for that.

The screen, system audio and microphone are handled locally in the browser by MediaRecorder/AudioContext, are never uploaded, and the ffmpeg CDN is not loaded; the ffmpeg core is downloaded for the first time only when you send the WebM to the workbench for MP4 conversion.