ProRes Proxy

Apple ProRes is a family of DCT-based intra-frame codecs (Proxy, LT, 422, 422 HQ, 4444 and 4444 XQ) that has become the default intermediate across professional post. ProRes Proxy is the lightest member, the entry tier designed specifically for offline editing rather than mastering. Apple targets it at roughly 45 Mbps for 1080p at 30 fps, scaling up with resolution and frame rate, which is a fraction of what the higher tiers or the camera originals demand.

The detail many people miss is that even at the Proxy tier, ProRes is still 10-bit 4:2:2. It is a genuinely color-correct offline format, not a crude low-bit preview, which is why editors trust it for a rough grade and client review before conforming to the originals. Being intra-frame, every frame is encoded on its own with no interframe prediction, so scrubbing, J-K-L shuttling, reverse playback and frame-accurate trimming stay smooth even on an older machine where long-GOP H.264 would stutter.

ProRes Proxy is the recommended proxy format for Final Cut Pro and DaVinci Resolve, where ProRes is a first-class native codec and the media engine on Apple Silicon decodes several streams in hardware. Historically ProRes could only be encoded on macOS, but FFmpeg and DaVinci Resolve can now write it on Windows and Linux too, so a Proxy-based workflow is no longer Mac-only.

The trade-off against H.264 is size. A ProRes Proxy file is larger than an equivalent H.264 proxy, because intra-frame compression is less aggressive than long-GOP, but it is still ten to fifty times smaller than the camera originals and far smoother to edit. The practical rule is simple: pick ProRes Proxy when your NLE is Final Cut Pro or Resolve and you want clean 10-bit 4:2:2 playback, and reach for H.264 when you need the smallest possible file for Premiere or a weak connection.