Your files stay on your Mac.
Converting iTunes M4V to AU pulls the audio stream out of your video file and writes it as a Sun AU audio file. The video frames are discarded; you get a clean AU waveform ready for any audio tool that reads the format. All processing runs locally — your M4V files never leave the Mac.
Drag one file or an entire folder of M4V files into Convertessa. Batch processing handles as many files as you have in one pass.
Choose AU from the output format list. Convertessa extracts the audio stream from each M4V and writes it as a Sun AU audio file.
Click Convert. The AU files appear beside your originals — no upload, no server wait, everything runs on 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.
Only the audio track is kept. Convertessa extracts the audio stream and writes it as an AU file; the video frames are discarded. If you need the video in a different container, choose a video output format instead.
Yes. Drop a folder onto Convertessa or run convertessa /path/to/folder --to au in the terminal. Every M4V inside the folder is converted to AU in one pass.
No. Convertessa runs entirely on your Mac. Your files are never sent to any server — the audio extraction happens locally every time.