Your files stay on your Mac.
AAC stores audio with lossy compression to keep file sizes small. AIFF packages audio as uncompressed PCM, the format DAWs, audio editors, and mastering tools expect. Convertessa decodes each AAC file on your Mac and writes standard AIFF output—nothing is uploaded anywhere.
Drag one AAC file or an entire folder into Convertessa. All decoding happens locally on your Mac—files never leave your machine.
Choose AIFF from the output format list. Convertessa preserves the original audio resolution and strips embedded metadata from the output.
Click Convert. Each AAC file is decoded and written as a standard AIFF file alongside the original, ready to open in any audio editor or DAW.
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. AIFF is an uncompressed container, but the audio data comes from the AAC source, which was already lossy-encoded. The output matches the fidelity of the source—converting does not recover information discarded during AAC encoding.
Yes. Convertessa strips embedded metadata from the output AIFF file as part of the conversion.
Yes. Drop an entire folder onto Convertessa and it converts every AAC file inside to AIFF in one batch. From the command line: convertessa ./my-files/ --to aiff.