Do not assume MOV means one codec
MOV is a container used by phone cameras, screen recordings and professional editing codecs. The actual tracks determine whether the browser can copy or must transcode them.
Preserve compatible tracks
When a source track already fits MP4, avoiding a transcode is preferable because it is faster and preserves the encoded quality.
Use fast-start MP4 for web use
Placing MP4 metadata where players can read it early improves progressive playback and upload processing workflows.
Review professional-camera sources carefully
ProRes, alpha video and unusual color workflows can need specialized desktop tooling. OpenFileTools reports browser limitations rather than flattening them silently.
Official marketplace references
Requirements can change. Review the source before publishing an important listing.
Mediabunny browser media toolkit documentation ↗