Your files stay on your Mac.
Convertessa decodes your Ogg Vorbis files and rewrites the audio stream into AU, the uncompressed audio format originated by Sun Microsystems and widely supported on Unix and macOS systems. The converter works entirely on your Mac — no files are uploaded, no internet connection is required. Drop an entire folder and every .ogg inside is converted in one pass.
Drag one file or an entire folder of .ogg files onto Convertessa. The app reads every Ogg Vorbis stream it finds, including multi-file batches.
In the output format list, choose AU. Convertessa will write standard AU files (.au) at the original sample rate and channel count.
Click Convert. Convertessa processes each file locally and saves the .au output alongside the originals. No data leaves your Mac.
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. Ogg Vorbis is a lossy format, so some audio data was discarded when the source file was originally encoded. Converting to AU preserves exactly what is in the .ogg file — it does not restore removed information. The resulting AU file is an uncompressed representation of the decoded Ogg stream.
Yes. Convertessa strips embedded tags and metadata from the output AU file. The audio content is preserved; identifiers such as artist, title, and comment fields are not carried over.
Yes. Pass the folder path with convertessa /path/to/folder --to au and Convertessa converts every Ogg Vorbis file it finds inside. You can also drag the folder onto the app window in the GUI.