Your files stay on your Mac.
Convertessa pulls the audio track from each MP4 and writes it to AIFF — Apple's uncompressed audio format. No lossy re-encoding takes place: the output preserves the original sample rate and bit depth. Every file is processed locally; nothing is uploaded.
Drag individual MP4 files or an entire folder onto Convertessa. The app queues as many files as you give it.
Choose AIFF from the output format list. Convertessa will extract the audio track from each video and write it to a lossless AIFF file.
Click Convert. AIFF files appear alongside the originals. No upload, no account — processing stays entirely on 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.
Yes. AIFF stores audio as uncompressed PCM data. Converting from MP4 extracts the audio track without re-encoding it through a lossy codec, so fidelity is fully preserved.
Yes. Convertessa removes embedded metadata from audio and document output files, giving you a clean AIFF with no leftover tags from the source MP4.
Yes. Drop a folder onto the app, or run convertessa ./videos --to aiff in the terminal. Every MP4 in the folder is converted in one pass.