Your files stay on your Mac.
WMA is Windows Media Audio — a proprietary Microsoft format that Apple devices and iTunes do not natively support. Converting to Apple M4A rewraps the audio in an AAC-based container that plays natively on every Apple device, in GarageBand, and in any standards-compliant player. The conversion runs entirely on your Mac; your files never touch a server.
Drag one WMA file or an entire folder into Convertessa. Batch mode processes every WMA in the folder in a single pass.
Choose Apple M4A from the output format list. Because M4A uses lossy AAC encoding, you can also set quality to balance file size against audio fidelity.
Click Convert. Convertessa writes the M4A files alongside your originals and leaves the source WMA files untouched.
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 stores audio as AAC, which is lossy. Convertessa lets you set quality before converting so you can choose the trade-off between file size and fidelity that suits your needs.
Yes. Drop a folder onto Convertessa or run convertessa ./folder --to m4a in the terminal and every WMA file inside is converted in one go.
No. Convertessa converts everything locally on your Mac. Your WMA files never leave your machine.