Your files stay on your Mac.
AMR is a speech-codec format used for mobile voice recordings and legacy voicemail systems. Apple CAF (Core Audio Format) is a flexible container native to macOS and iOS, supported by QuickTime, GarageBand, and the Core Audio stack. Convertessa rewraps your AMR audio into CAF entirely on your Mac — nothing is uploaded.
Drag one or more AMR files — or an entire folder — onto Convertessa, or use File → Open to browse your Mac.
In the output format list, Choose Apple CAF to set CAF as the target container.
Click Convert. Convertessa rewraps each file locally and saves the CAF output alongside the originals. No file leaves your Mac.
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.
No additional quality loss is introduced. Convertessa decodes the AMR audio and writes it into the CAF container without re-encoding to another lossy format.
Yes. Drag the folder onto Convertessa, or run convertessa /path/to/folder --to caf to batch-convert every AMR file in one pass.
Yes. Embedded metadata is stripped from the AMR source during conversion, so the output CAF files contain only the audio stream.