What you see
“Your browser cannot play that file. MP4 and WebM work everywhere; MKV, AVI and ProRes do not.” Or “That file has no readable video track.”
Why it happens
The video tools read your video through the browser’s own video player. A browser plays the formats the web uses — MP4 and WebM — and very little else. MKV and AVI files, ProRes from a camera or an editing app, and old formats such as WMV or FLV will not open, however well they play in a desktop player such as VLC.
iPhone videos are MOV files, which usually open. Ones recorded in the High Efficiency setting use HEVC, which some browsers and computers cannot decode.
What to do
- Convert the file to MP4 first, with a desktop app such as HandBrake or VLC. The Video Converter here cannot help with this particular step, because it reads the video through the same browser player.
- Try another browser for an iPhone video that will not open. Safari plays HEVC, and so does Chrome on most recent computers.
- Record in a more compatible format next time. On an iPhone, Settings, Camera, Formats, Most Compatible records H.264, which opens everywhere.