Your files stay on your Mac.
TTA (True Audio) compresses AU audio without discarding a single sample, so the output is bit-for-bit identical to the source. Convertessa reads your AU files, encodes them to TTA locally, and writes the result to disk—nothing is sent to a server. Metadata is stripped from each output file.
Drag one AU file or an entire folder into Convertessa. The app queues every AU track it finds, ready for conversion.
Choose TTA from the output format list. Because TTA is lossless, there is no quality slider—every sample from the source is preserved exactly.
Click Convert. Convertessa encodes each AU file to TTA on your Mac and saves the results alongside the originals. No internet connection is needed at any point.
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. TTA (True Audio) is a lossless codec. Every audio sample present in the AU source is reproduced identically in the output—no data is discarded during encoding.
No. Convertessa runs entirely offline. AU files are read from disk, encoded to TTA locally, and written back to your drive. No network connection is used.
Yes. Drop a folder onto Convertessa, or run convertessa ./folder/ --to tta in the terminal to convert every AU file inside in one pass.