Your files stay on your Mac.
Convertessa extracts the audio stream from each Matroska MKV container and writes it as an Apple Core Audio Format file. The resulting CAF file is natively readable by macOS, iOS, and Core Audio toolchains. All processing happens on your Mac — no file is uploaded anywhere.
Drag one file or an entire folder of MKV files onto Convertessa. Batch mode processes every file in the folder in one pass.
Choose Apple CAF from the output format list. Convertessa will extract the audio stream from each MKV and write a CAF file alongside the original.
Click Convert. Your CAF files appear next to the originals the moment the job finishes — no account, no upload, no waiting on a server.
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 extracts the first audio track in the MKV container. If you need a specific track, demux the file with a tool such as mkvextract first, then pass the resulting audio file to Convertessa.
Yes — CAF wraps PCM or other Core Audio codecs, so the audio is decoded from its original MKV codec and written into the CAF container. The process runs entirely on your Mac; no data is sent to any server.
Yes. Drop a folder onto Convertessa or use the CLI: convertessa *.mkv --to caf. Every MKV in the selection is converted in one batch.