CAF
Apple's modern, container-smart audio.
Where it came from
CAF (Core Audio Format) was introduced by Apple in 2005 with Mac OS X 10.4 to fix AIFF's limits: AIFF capped files at 4 GB (32-bit sizes) and choked on metadata.
CAF uses 64-bit chunk sizes and a flexible tag system, so it handles huge recordings and rich annotations. It is the native format of Logic Pro.
How it works
Like AIFF, CAF is a chunk container, but every field is 64-bit and chunks can nest. It can hold PCM, AAC, or any codec Apple supports, plus markers and regions.
UWC converts CAF alongside other audio formats in the browser studio — no file size ceiling to worry about.