Your files stay on your Mac.
Convertessa decodes each MP3 and writes the audio as uncompressed PCM inside an AIFF container — the format professional DAWs and audio editors natively import. Every file is processed on your Mac; nothing is uploaded. Batch-convert a whole folder with a single drag or one terminal command.
Drag one MP3 or an entire folder onto Convertessa. All files are queued immediately with no size limit.
Choose AIFF from the output format list. Convertessa will decode each MP3 and write an uncompressed AIFF file ready for your DAW or editor.
Click Convert. Each MP3 is decoded and saved as an AIFF beside the original. No internet connection required — 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.
No. MP3 is a lossy format — some audio data was discarded when the file was originally encoded. Converting to AIFF unpacks the remaining audio into an uncompressed container but cannot restore what was lost. The output AIFF will be larger and fully editable in any DAW, but its fidelity is bounded by the source MP3.
Many professional DAWs and video editors — including Logic Pro and Final Cut Pro — prefer or require AIFF input when importing audio stems or sound effects. Convertessa handles the decoding step locally so you can bring MP3 assets into those workflows without involving a cloud service.
Yes. Drop the folder onto Convertessa, choose AIFF, and every MP3 inside is queued and converted in one pass. From the terminal: convertessa /path/to/folder --to aiff processes the entire folder with one command.