Your files stay on your Mac.
AC-3 (Dolby Digital) is a compressed surround audio format common in video files and disc media. Converting to Ogg Vorbis produces an open, patent-free audio stream compatible with browsers, Linux, and open-source media players. Convertessa decodes the AC-3 bitstream and re-encodes it to Ogg Vorbis entirely on your Mac — no upload, no network required.
Drag one AC-3 file or an entire folder of them onto Convertessa. The app reads .ac3 files and AC-3 streams extracted from containers.
Choose Ogg Vorbis from the output format list. Because Ogg Vorbis is a lossy format you can also set quality — higher values produce larger files with more detail preserved.
Click Convert. Convertessa processes every file locally and writes the .ogg output beside the originals. Batch jobs run in parallel.
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.
Ogg Vorbis supports multichannel audio, so a 5.1 AC-3 source is decoded and re-encoded with all channels intact. Channel layout is preserved as-is — no downmix is applied.
Yes. Because Ogg Vorbis is a lossy format, Convertessa lets you set quality before converting. A higher quality value retains more audio detail at the cost of a larger file size.
No. Convertessa converts entirely offline. Your AC-3 files are never uploaded to any server — the conversion runs as a local process and writes output to your disk.