Question 1

Why does conversion happen in the browser instead of on a server?

Accepted Answer

Because your file never has to travel. A 500 MB video would take minutes to upload and minutes to download again; converting locally skips both, and the file stays private.

Question 2

Why is my file rejected?

Accepted Answer

The browser's WebCodecs engine can only handle codecs it knows. Some older AVI and MKV codecs are supported by no browser at all and need a desktop program such as VLC or HandBrake.

Question 3

How large a video can I convert?

Accepted Answer

We impose no limit. Your device's memory is the real constraint: clips up to a few hundred megabytes convert comfortably on a normal laptop, while multi-gigabyte files may run out of memory.