Why MOV files get large
Resolution, frame rate, duration, and the source camera's own bitrate all drive file size far more than which container the video is wrapped in. A short, low-resolution MOV can be tiny; a long 4K one can be enormous. The extension alone does not tell you much.
What QuickCompress does with a MOV file
QuickCompress accepts MOV input in V1, provided the file contains a valid, supported video stream; an audio-only file is not a supported input. The standard compression strategy uses hardware-accelerated H.264 encoding through Apple VideoToolbox, with AAC audio when the source contains an audio track. Output in V1 is always a compressed MP4.
Compressing it, step by step
Drop the MOV file into QuickCompress, choose an outcome (a smaller file, or a specific target size), and let it encode locally using your Mac's hardware encoder. Your original MOV is left exactly where it was; the compressed MP4 is a new, separate file.
Picking a target size
If you are compressing the MOV to fit a specific limit rather than just "smaller", see how to compress a video to a specific file size for the full walkthrough of target-size mode.
Frequently asked questions
Does compressing a MOV file turn it into an MP4?
Yes. QuickCompress V1 always outputs a compressed MP4, regardless of whether the input was MOV or MP4. Your original MOV file is left untouched as a separate file.