Question 1

Does the video come out as WebM or MP4?

Accepted Answer

Always WebM. The browser records natively in that format through MediaRecorder, producing MP4 would require converting the video afterward, a heavy process that either freezes the tab (in a build without origin isolation) or needs resources that would hurt the rest of the site's loading. WebM is open, has excellent quality with the VP9 codec, and plays natively in practically every modern browser and player, including VLC.

Question 2

Is the recorded video uploaded to any server?

Accepted Answer

No. Screen capture, audio mixing and recording all happen entirely in your browser, using native APIs (getDisplayMedia, getUserMedia, MediaRecorder). The final file only exists locally until you click download, nothing is ever sent anywhere.

Question 3

Can I record system audio together with the microphone?

Accepted Answer

Yes, when the browser offers that option (Chrome and Edge usually let you capture a tab or screen's audio while sharing; Firefox and Safari have more limited support). The two audio sources are mixed into a single stream through the Web Audio API, each with its own gain control and independent level meter, so you can balance the relative volume before you even start recording.

Question 4

How does the webcam overlay work?

Accepted Answer

The webcam picture is drawn in a corner of the recorded screen (or centered, if you prefer), as a rectangle or a circle, at an adjustable size. This is done by compositing the screen and the webcam onto a canvas in real time and recording that canvas's output, so the overlay is already baked into the final video, no editing needed afterward.

Question 5

Can I pause the recording partway through and continue later?

Accepted Answer

Yes, for real: the pause button uses MediaRecorder's native pause method, so the paused time never enters the final video or the generated file, unlike simply hiding the screen for a while.

Question 6

Can I trim just a section of the recording before downloading?

Accepted Answer

Yes, with one important caveat: without a full video converter running in the browser (which this tool deliberately avoids, see the next question), trimming works by playing back the marked section and re-recording that section as a new file. That re-encodes the video, so there can be a small quality loss compared to the original file, and the trim takes roughly as long as the trimmed section itself. If you need a trim with zero re-encoding, download the full file and cut it in a local video editor instead.

Question 7

Why doesn't the tool use a converter to produce MP4 or make exact cuts?

Accepted Answer

The fastest in-browser video conversion option (ffmpeg.wasm in multithreaded mode) requires the entire site to run under cross-origin isolation (COOP/COEP), a security header that breaks third-party ad rendering on the rest of the site. The version without that isolation is too slow for video. That is why this tool sticks to the browser's native recording APIs, more limited, but reliable and fast.

Question 8

Does it work on mobile?

Accepted Answer

Very limited. The getDisplayMedia API (screen capture) has practically no support in mobile browsers, on both Android and iOS, so recording a phone's screen through this tool generally does not work, the tool detects that and warns you instead of breaking silently. Recording just the webcam works better on mobile, but the experience was designed for desktop.

Online Screen Recorder