Your files stay on your Mac.
AC-3, also known as Dolby Digital, is the audio format required by DVD authoring tools, Blu-ray encoders, and broadcast workflows. Converting your MP3 files to AC-3 repackages the audio into the container those pipelines expect. Convertessa does every encode on your Mac — files never leave your machine.
Drag one file or an entire folder into Convertessa. All MP3s in a folder are queued for batch conversion in one pass.
Choose AC-3 from the output format list. Set quality to control how the lossy AC-3 stream is encoded.
Click Convert. Convertessa encodes each file to AC-3 locally with no upload and no account required.
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.
AC-3 (Dolby Digital) is the standard audio format for DVDs, Blu-ray discs, and digital broadcast streams. DVD authoring tools and video muxers commonly require AC-3 when building disc-compatible media.
Yes. Drop a folder into Convertessa or run convertessa /path/to/folder --to ac3 in the terminal. Every MP3 in the folder is converted in a single pass.
Yes. Convertessa strips embedded metadata (ID3 tags and similar) from the source MP3 during conversion, so the output AC-3 file contains only the audio stream.