Audio & Video

Trim, fade, normalise and convert audio; turn a video into a GIF or re-encode it to MP4 or WebM; and record your screen, camera or microphone straight to a file.

Media is the category where local processing matters most for the plainest reason: the files are enormous. Uploading a 400 MB screen recording to convert it, then downloading the result, is slower than doing the work on the machine the file is already on. That the footage is often private — a call recording, a screen with credentials on it — is the second reason. Encoding uses a media engine compiled to WebAssembly, fetched once when you first need it.

Before changing a file it is worth knowing what is in it: the container, the codecs, the resolution and frame rate, the bitrate and channel layout — and whether your own browser can play it at all, which is the answer that explains most won’t-play problems without any conversion.

Before a call, the same camera and microphone can simply be checked: a live picture with the size and frame rate it is really sending, a level meter and a few seconds recorded and played back, and a tone on each speaker in turn — nothing saved unless you ask, nothing sent.