Your files stay on your Mac.
Converting iTunes M4V to Opus pulls the audio track from your video file and re-encodes it as an Opus stream. Opus is an open, royalty-free codec that delivers excellent quality at low file sizes, whether the source is music, dialogue, or mixed content. You can set the quality level before you convert.
Drag individual .m4v files or an entire folder into Convertessa. Batch conversion processes every file in one pass — no need to queue them one by one.
Pick Opus from the output format list. Adjust the quality slider to balance file size against audio fidelity before converting.
Click Convert. Convertessa extracts the audio track and writes .opus files to your chosen destination — no internet connection required, and EXIF metadata is stripped from the output.
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. Opus is an audio-only format. Convertessa extracts the audio track from the M4V and discards the video stream, producing a standalone .opus file.
Yes. Because Opus is a lossy format, Convertessa lets you set the quality level before converting. A higher setting produces better-sounding audio at a larger file size; a lower setting keeps files compact.
No. Convertessa runs entirely on your Mac. Your M4V files are read and written locally — nothing is sent to any server.