Screen Recorder
- Ready
- Status
- 0.0s
- Length
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- Size
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- Format
Nothing leaves your device
The recording is assembled in memory and downloaded from your browser. There is no upload, no account and no copy on any server.
The screen recorder captures your screen, a single window or one browser tab to a WebM file using the browser recording APIs. The recording is assembled in memory and saved directly to your device. It is never sent anywhere, which is the difference between this and most free screen recorders.
How it works
Two browser APIs do the work. getDisplayMedia asks the operating system for a video stream of whatever you pick, and MediaRecorder encodes that stream to WebM as it arrives.
- Choose whether to include microphone audio, then start the recording.
- The browser shows its own picker, entire screen, an application window, or a browser tab. This picker is the browser’s, not the page’s, and a page cannot preselect for you.
- Recording begins once you confirm. The elapsed time and captured size update as it runs.
- Stopping assembles the chunks into a single WebM file and offers it for download.
Tab capture can include the tab’s own audio; window and full-screen capture generally cannot, because operating systems do not expose per-window audio to the browser. Microphone audio is mixed in separately when you enable it.
Examples
A narrated walkthrough
Source
One browser tab
Microphone
On
Result
A WebM file with tab video and your voice
Tab capture keeps the recording tightly framed and avoids catching notifications from elsewhere on your screen.
A silent bug reproduction
Source
Application window
Microphone
Off
Result
A video-only WebM, roughly 1 to 3 MB per minute
Size depends heavily on how much of the picture changes. A mostly static form is small; a scrolling page or video is many times larger.
Frequently asked questions
Is the recording uploaded anywhere?
No. The stream is encoded in your browser and the finished file is written straight to your downloads. Nothing leaves the device, which is worth checking before using any web screen recorder for anything confidential.
Why can I not record system audio?
Because most operating systems do not expose it to the browser. Chrome can capture a browser tab’s own audio, and on Windows it can sometimes capture full-screen audio, but window capture almost never includes sound. Enable the microphone for narration instead.
Why is the file WebM rather than MP4?
WebM with VP8 or VP9 is what MediaRecorder supports across browsers. It plays in every modern browser and in VLC, but some video editors and older players will not open it. Convert it if the destination needs MP4.
How long can I record?
Until you run out of memory, since chunks are held in the tab rather than written to disk as they arrive. A few minutes is comfortable; recordings beyond roughly fifteen minutes risk the tab being killed, so a desktop recorder is the better tool for anything long.
Does it work on a phone?
No. getDisplayMedia is not implemented on mobile browsers, so screen capture from a phone needs the operating system’s built-in recorder.