SizeCap compresses a video on iPhone or iPad to a file size you type. You enter a limit in MB, say an email or upload-form cap, and the app works back to a bitrate. After export it reads the file's real size. If the file is over, SizeCap re-encodes once with a corrected bitrate; if that still misses, it deletes the file and asks for a larger cap. If the clip is too long for the cap, it tells you the smallest size that would work.

The default output is HEVC with two-pass encoding (one pass on hardware that can't do two). H.264 is there for older players. Presets fill in limits for email, Discord, WhatsApp and Teams.

Compression runs on the device, and the app has no networking code of its own. One video at a time is free. SizeCap Pro, a one-time purchase, compresses up to 50 in one run.