Your files stay on your Mac.
Converting AVI to Apple M4A extracts the audio track from your video and packages it as an AAC M4A file — ready for Apple Music, iPhone, or any AAC-capable player. Because M4A is a lossy format, you can set quality to balance fidelity against file size. Every conversion runs locally on your Mac; nothing is uploaded.
Drag a single AVI or a whole folder of videos onto Convertessa. The app queues every AVI it finds automatically.
Pick Apple M4A from the output format list, then set quality to control how much audio fidelity you want in the result.
Click Convert. Convertessa pulls the audio from each AVI and writes an M4A file next to the original — offline, no upload required.
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.
M4A uses AAC, a lossy codec. Use the quality slider in the app (or --quality on the CLI) to set the level of fidelity you need. Higher quality means larger files.
Yes. Drop a folder onto Convertessa or run convertessa ./folder/ --to m4a and every AVI inside is converted in one pass, with no upload.