Your files stay on your Mac.
Apple CAF is a lossless container used by Core Audio — large, uncompressed, and unplayable on most non-Apple devices. Converting to MP3 re-encodes the audio into a lossy, universally supported format that plays everywhere. You set the quality level; Convertessa handles the encoding.
Drag a single .caf file or an entire folder onto Convertessa. Every file stays on your Mac — nothing is uploaded.
Select MP3 from the output format list, then set your preferred quality level to balance file size against audio fidelity.
Click Convert. Convertessa encodes each CAF file and saves the resulting MP3s alongside the originals.
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.
Yes. Convertessa removes embedded metadata during conversion, giving you clean MP3 files with no leftover Core Audio tags.
Yes. Drag an entire folder onto Convertessa and every .caf file inside is converted to MP3 in one pass. You can also use the CLI: convertessa /path/to/folder --to mp3.
MP3 is a lossy format, so some reduction from the original CAF is unavoidable. Setting a higher quality level preserves more detail at the cost of a larger file; lower quality produces smaller files with more compression artefacts. Convertessa lets you choose the trade-off before converting.