What is a screen recorder?

A screen recorder makes a video of what happens on your screen: a whole display, one app window, or a single browser tab. It is the quickest way to show a bug to a developer, walk a colleague through a setting, record a tutorial or a presentation, or keep a copy of a video call. With the microphone on, you can talk over what you show.

Tool description

This tool records your screen right in your browser, without installing an app or an extension. Choose what to share in the browser's dialog, record with the sound of the screen and your microphone, pause and resume as you go, and stop when you are done. The recording then opens in a player with a timeline, where you can trim the start and end and download it as it was recorded, or as an MP4 or an animated GIF. Nothing is uploaded: the video is recorded and processed on your device.

Features

  • Record the entire screen, a window, or a browser tab
  • Record the system or tab audio, your microphone, or both mixed together, and pick which microphone to use
  • Record as MP4 (H.264) or WebM (VP9 or VP8), depending on what your browser supports
  • Choose the resolution from the original size down to 480p, the frame rate from 15 to 60 fps, and the video quality
  • Countdown of 3, 5, or 10 seconds before recording starts, so you can switch to the window you want to show
  • Pause and resume, with a live preview and the recording time and file size as it grows
  • Stop from the tool or with the browser's own "Stop sharing" button
  • Trim the recording on a timeline with thumbnails and the audio waveform, drag the start and end handles, or type the times
  • Download the recording as it is, cut it without re-encoding, or convert it to MP4 or an animated GIF
  • WebM recordings get their length written in, so players show the duration and can seek in them

How it works

The tool asks the browser to share the screen with the Screen Capture API and records the picture and sound with the MediaRecorder API. When both the system audio and the microphone are on, the two are mixed into one track with the Web Audio API. Browsers write WebM files while the length is still unknown, so the tool adds the duration to the file header when recording stops. Trimming and converting run FFmpeg, compiled to WebAssembly, on your device. Keeping the recorded format copies the video without re-encoding, which is fast and lossless but starts the cut on the nearest keyframe. MP4 re-encodes the video with H.264 and AAC, and the GIF is made at 10 frames per second and at most 960 pixels wide.

Tips

  • In Chrome and Edge, the sound of a browser tab can always be shared. Whether the sound of the entire screen can be shared depends on the system, so share a tab if you need its sound.
  • Turn on audio sharing in the browser's dialog, or the recording has no system sound even with Record system audio on.
  • MP4 is the best choice to share the recording, since it plays on nearly every device. If your browser only offers WebM, convert the recording to MP4 when you download it.
  • Screen text stays sharp at the original resolution and High or Very high quality. Lower the resolution or the quality for smaller files.
  • A GIF has no sound and gets large quickly, so trim it to the few seconds you need.
  • The first trim or conversion downloads FFmpeg, about 30 MB. Downloading the recording as it is needs no download.
  • Mobile browsers can't record the screen. Use a desktop browser such as Chrome, Edge, Firefox, or Safari.