Your files stay on your Mac.
WavPack stores audio in a lossless container, so Convertessa decodes each M4A and repackages the audio stream without introducing further encoding artefacts. The resulting .wv files are suited for archival and hybrid-mode playback workflows. The entire conversion runs on your Mac—no file ever leaves your machine.
Drag one file or an entire folder into Convertessa. It queues every .m4a it finds, including files in subfolders.
Select WavPack from the output format list. Convertessa sets .wv as the target for every file in the queue.
Click Convert. Convertessa processes each file locally on your Mac and writes the .wv output without sending anything to 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.
No. M4A files typically contain AAC-encoded audio, which is already lossy. Convertessa decodes that audio and packages it into WavPack losslessly, so no additional quality is lost—but quality removed during the original AAC encoding cannot be recovered.
Yes. Drop a folder onto Convertessa, or run convertessa /path/to/folder --to wv, and it processes every .m4a it finds in one pass.
No. Convertessa runs entirely offline on your Mac. Your M4A files are decoded and written to WavPack locally—nothing is sent to any server.