Your files stay on your Mac.
Convertessa reads the audio track from your Windows Media Video files and re-encodes it as Opus — an open, royalty-free audio codec tuned for both speech and music at low bitrates. Because Opus is a lossy format, you can set quality to control the trade-off between file size and fidelity before you convert. Every file stays on your Mac; nothing is uploaded.
Drag one WMV file or an entire folder into Convertessa. The app reads the embedded audio track from each file and queues them for conversion.
Pick Opus from the output list. Because Opus uses lossy compression, you can set quality to dial in the balance between file size and audio fidelity that suits your workflow.
Click Convert. Convertessa encodes every file locally and saves the Opus output alongside the originals. No upload, no account, no waiting on 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.
Yes. Convertessa writes a new .opus file and leaves the original WMV untouched.
Yes. Drag the folder into Convertessa or run convertessa ./folder/ --to opus from the terminal. Every WMV file in the folder is processed in one pass.
Convertessa extracts the full audio track from the WMV container and encodes it as Opus. The duration and channel layout are preserved; only the codec changes.