APE (Monkey's Audio) is a lossless codec known for squeezing files smaller than FLAC at the cost of heavier decoding. It was a favorite of Windows-based CD archiving for years, so large collections often contain a stretch of .ape rips.
Why iPhone can't play APE natively
iOS has never supported Monkey's Audio, and neither have most players on any platform — APE support is thin even on desktop. The standard advice is to batch-convert APE to FLAC, which works but means re-encoding an archive that was fine as it was, and re-checking tags on the other side.
How BTR AMP plays APE
BTR AMP plays APE files directly — support arrived in version 15.0 together with Musepack, TTA, WavPack, and the OGG codecs. Rips play losslessly as-is, with the exact codec shown per track, and the on-device metadata editor handles APE tags natively. Gapless playback keeps continuously-ripped albums seamless, and your APE files share one library with FLAC, ALAC, and everything else BTR AMP plays.
Getting your APE files onto your iPhone
APE archives move over like any other files.
Send files over Wi-Fi from any browser on your computer (Connect → Wi-Fi Transfer), pull them from Google Drive, OneDrive, iCloud Drive, an SMB share, or WebDAV, use AirDrop, or play straight from a USB drive. The transfer guide walks through each method, and the importing guide covers the details.