Your files stay on your Mac.
MP4 is a container that bundles video and audio together. Converting to Apple CAF unwraps the audio track and rewraps it in Apple's Core Audio Format — the native container used by macOS and iOS toolchains. No re-encoding means the audio data is carried over exactly as stored in the source file.
Drag one MP4 or an entire folder of them into Convertessa. Batch mode processes every file in one pass without any extra setup.
Pick Apple CAF from the output format list. Convertessa targets the .caf container and preserves the original audio resolution.
Click Convert. Convertessa works entirely on your Mac — files never leave your machine — and writes .caf files alongside your originals or to a folder you choose.
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.
Convertessa rewraps the audio stream into the CAF container. The audio data is preserved at its original quality — no lossy re-encoding step is applied.
Yes. Drag the folder onto Convertessa or run convertessa ./folder/ --to caf from the terminal. Every MP4 in the folder is converted in a single batch.
Yes. Embedded metadata and EXIF tags are stripped from the output file during conversion.