Your files stay on your Mac.
Converting MP4 to MP3 pulls the audio track out of your video and writes it as a standalone audio file. The video stream is discarded — only the sound is kept. Convertessa runs the whole process locally on your Mac; files never leave your machine.
Drag one MP4 or an entire folder into Convertessa. Every MP4 in the folder is queued for conversion in a single batch.
Choose MP3 from the output format list. Use the quality slider to control how the audio is encoded — higher quality means a larger file.
Click Convert. Convertessa extracts each audio track and writes the MP3 files alongside the originals. Nothing is uploaded; everything happens 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. MP3 is an audio-only format. Convertessa extracts the audio track and discards the video stream. Your original MP4 file is left untouched.
Yes. Drop a folder onto Convertessa or pass a directory to the CLI — convertessa ./videos/ --to mp3 — and every MP4 in that folder is converted in one pass.
No. Convertessa runs entirely offline on your Mac. No internet connection, no account, and no cloud service is involved — your files never leave your machine.