Screen Recorder – Record Your Screen, a Window or a Tab Without Installing Anything
This online screen recorder captures your entire screen, a single window or one browser tab, mixes in your microphone and the tab or system sound, and saves an MP4 or WebM video. Capturing, mixing and encoding all happen inside the browser tab with the browser's own Screen Capture and WebCodecs APIs, so the recording is never uploaded. There is no account, no watermark and no time limit apart from the storage on your computer.
How browser screen capture works
When you click Start recording, the browser opens its own sharing picker. The page never sees your screen until you choose what to share, and the browser shows a sharing bar or indicator for as long as the capture runs. That bar appears in full-screen recordings too; most browsers let you hide or move it. Clicking the bar's Stop sharing button ends the recording just like the Stop button here. Before you start, turn on Do Not Disturb so chat and email notifications aren't recorded, and check which window is highlighted in the picker.
Why screen recordings are so small
Video encoders only spend bits on what changes between frames. A still slide or a document you are reading costs almost nothing, while scrolling, playing a video or switching windows makes the data rate jump. The estimate shown before you start, such as up to ≈ 45 MB per minute for 1080p at 30 fps, is a ceiling; the live data-rate chart shows the real cost second by second, and typical recordings land far below the line. If a file still turns out too large to share, the Video Compressor can shrink it to a target size.
Choosing a frame rate and resolution
- 15 fps is enough for slides and code walkthroughs where little moves.
- 30 fps suits most tutorials, demos and bug reports.
- 60 fps keeps scrolling, cursor movement and games smooth, at roughly twice the data.
High-resolution displays are often 2880 × 1800 or larger. Recording at 1080p keeps text sharp while cutting the file size and the work the encoder has to do. The tool always encodes even dimensions, because H.264 rejects odd sizes, which window captures often have.
Keyframes: why every 2 seconds matters
A keyframe is a complete picture that the following frames are built on. Browsers' own recorders can leave keyframes far apart and write WebM files with no duration or seek index, which makes them slow to scrub and awkward to edit. This recorder encodes at a constant frame rate with a keyframe every 2 s and writes a proper index, so the file seeks instantly and cuts cleanly in the Video Trimmer, whose lossless mode cuts on keyframes.
Microphone, system audio and echo
Screen audio and your microphone are mixed into one track, because most players only play one. The level meters let you test the microphone before you start, and warn when it is too quiet or clipping. If you record computer sound and use speakers at the same time, the microphone picks up the speakers and every sound is recorded twice, slightly delayed.
Showing your webcam
The camera bubble opens your webcam in a small floating Picture-in-Picture window that stays on top of other apps. Because it is a real window, it appears in entire-screen recordings without the page having to draw anything, which keeps it smooth even while this tab is in the background.
Where long recordings are stored
In Chrome and Edge you can save straight to a file on disk as you record, with no practical length limit. Otherwise the recording is written to the browser's private storage, and as a last resort kept in memory up to 1 GB. The tool tells you the limit before you start and stops safely before it is reached. After recording, convert clips with the Video to GIF Converter or pull out the narration with the Video to MP3 Converter.
Credits
Encoding and file writing use Mediabunny, an open-source media toolkit for the browser by Vanilagy, licensed under MPL-2.0 (source on GitHub).