How to record your screen
- Choose the sound: the screen's or tab's own sound, your microphone, or both.
- Press Start recording. The browser asks what to share: a browser tab, one window or the entire screen. Tick Share audio there if you want the sound.
- Do what you want to record. Press Pause to leave something out, and Stop and save (or the browser's Stop sharing button) when you are done.
- Watch the video on the page, then press Download.
Why a browser screen recording can show no length
Every online screen recorder that works without an install uses the same two pieces of the browser: one that captures the screen and one, called MediaRecorder, that turns it into a video file. We tested what MediaRecorder actually writes in Chrome 155, and found three catches.
| What the page asks for | What Chrome writes | The catch |
|---|---|---|
| "MP4", with no codec named | MP4 with VP9 video and Opus sound | A pairing that QuickTime and many video editors don't open |
| MP4 with H.264 and AAC | A fragmented, streaming-style MP4 | Windows Explorer shows no length and a bit rate of 0 kbps |
| WebM (also what Firefox records) | WebM without a length | Players show the length as unknown and can't skip ahead |
This page asks for H.264 video and AAC sound by name, the pairing that plays on phones, Macs, Windows, TVs and every editor. When you stop, it copies the recorded video and sound into a standard MP4 with the length in its header. Nothing is re-encoded, so the picture is exactly what the browser recorded. In our test a 7-second recording showed 00:00:07 and 159 kbps in Windows Explorer after repackaging; the same recording as Chrome wrote it showed an empty length and 0 kbps. WebM recordings are repackaged the same way and come out with their length written in. If you need the file exactly as the browser wrote it, Download as recorded keeps that too.
Sound: the screen, the microphone, or both
The browser treats shared sound like a microphone in a video call. In our test Chrome reported echo cancellation, noise suppression and automatic level control as switched on for the shared sound unless the page asked otherwise. Those filters are good for a voice and bad for music and video sound: in our voice recorder test the same noise suppression faded a held note by 8 dB in eight seconds. This page turns them off for the screen's sound and keeps them on for your microphone, where they remove hiss and even out your voice.
A video file can hold one sound track that every player plays, so when you choose both, the screen's sound and your microphone are mixed into it. Use headphones while you talk, or the microphone also picks up the computer's speakers and you hear everything twice.
Tips for a good screen recording
- Share a tab or a window rather than the whole screen when you can: notifications from other apps stay out of the video, and the file is smaller.
- 30 fps is plenty for slides, documents and software demos. Choose 60 fps for games or anything that scrolls fast; the file is larger.
- Pause instead of cutting later: the paused time is left out of the video. In our test a recording of 5 seconds, a 2-second pause and 2 more seconds came out 7.05 seconds long.
- On a phone or tablet, use the screen recorder built into the system; mobile browsers don't let web pages record the screen.
To shorten the result, use Trim Video; to make it smaller for email or chat, use Compress Video; to turn a short clip into a GIF, use Video to GIF. The recording is made and saved on your device and is never uploaded.