Your files stay on your Mac.
Apple CAF (Core Audio Format) is Apple's native audio container, required for sound assets in macOS and iOS projects. Converting your MP3 files to CAF packages the audio into a format that Xcode, AVFoundation, and other Apple frameworks read natively. Convertessa runs entirely on your Mac — no files leave your machine.
Drag one MP3 file or an entire folder into Convertessa. Batch mode processes every file in one pass.
Choose Apple CAF from the output list. No further settings are needed — CAF is a lossless container, so your audio data is preserved exactly.
Click Convert. Your CAF files are saved alongside the originals — or to any folder you pick — without uploading anything.
Images, audio, video, documents, archives and eBooks — all converted natively, right on your Mac.
Pick a format you have — see everything Convertessa can turn it into.
Convert hundreds of files at once with per-type group defaults and individual overrides.
First-class support for HEIC, AVIF and WebP — encode and decode, both ways. Read JPEG XL and a dozen more modern formats too.
Drop files anywhere on the window. Native, instant, and exactly what you’d expect on a Mac.
Dial in compression, resolution and bitrate. Keep originals pristine or shrink for sharing.
Never overwrite a file by accident. Convertessa appends safe suffixes automatically.
Every job is logged locally. Re-run a previous conversion or revisit recent outputs in a click.
Bundle your converted files straight into a single ZIP, TAR or 7z — packaged and ready to share the moment a job finishes.
Right-click any file in Finder and choose Convert. A Quick Action handles it on the spot — no need to open the app first.
Shrink Convertessa to a tidy mini window that tucks into a corner — just a drop zone and a format picker for quick, one-off conversions.
No cloud. No account. No upload. Every conversion happens entirely on-device, using the power already in your Mac. What you convert is nobody’s business but yours.
Script conversions, wire them into your build, or batch a folder from the terminal. The same engine, no GUI required.
Read the full CLI documentation →Shrink Convertessa down to a small, focused window — drop, convert, done, with your recent conversions one click away.
macOS 14+ · Apple Silicon & Intel
New formats, new features, and fixes — every release, on the record.
CAF is Apple's flexible audio container designed for macOS and iOS. It supports large file sizes beyond the 4 GB limit of AIFF and WAV, stores metadata natively, and is the preferred format for audio assets in Xcode projects and AVFoundation-based apps.
Convertessa wraps your existing MP3 audio stream into a CAF container — it does not re-encode or alter the audio data. The quality stays exactly as it was in the source file.
Yes. Drop the folder onto Convertessa or use the CLI: convertessa /path/to/folder --to caf. Every MP3 in the folder is converted in one batch, and files never leave your Mac.