What if my file is bigger than 300 MB?
Re-encode it to HEVC with a sensible bitrate (15–40 Mbps for 4K is plenty). A short HEVC 4K loop usually fits in 20–80 MB.
Wallper limits each individual file to 300 MB so playback stays smooth on every Mac. If your master is heavier, re-encode it to HEVC (H.265) with a target bitrate between 15 and 40 Mbps for 4K. Most 10–30 second 4K loops compress to 20–80 MB at this bitrate without any visible quality loss.
For 1080p loops, 8–15 Mbps is usually more than enough. Tools like HandBrake, Compressor, or `ffmpeg -c:v libx265 -tag:v hvc1` produce App Store-friendly HEVC files that Wallper plays natively.