Your files stay on your Mac.
AU is a raw PCM audio container common in Unix and Java environments. Ogg Vorbis encodes that audio into a compressed, open-standard format with adjustable quality. Convertessa reads your AU files locally and writes Ogg Vorbis output — no upload, no account.
Drag one AU file or an entire folder into Convertessa. Your files never leave your Mac.
Choose Ogg Vorbis from the output list. Set quality to control the balance between file size and audio fidelity.
Click Convert. Convertessa processes every file locally and saves the Ogg Vorbis output alongside your originals.
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 runs entirely offline. Your AU files are read and written locally — nothing is sent to a server.
Yes. Drop a folder onto Convertessa or use the CLI: convertessa ./folder --to ogg. Every AU file in the folder is converted to Ogg Vorbis.
Because Ogg Vorbis is a lossy format, Convertessa lets you set quality before converting. Higher quality preserves more audio detail at the cost of a larger file.