Your files stay on your Mac.
Convertessa reads the audio track from your 3GP Mobile file and re-encodes it as an AAC stream inside an Apple M4A container. The resulting file plays natively in iTunes, Apple Music, and across Apple devices. All processing runs locally — your files never leave your Mac.
Drag one 3GP file, a selection, or an entire folder into Convertessa. No upload step — conversion reads directly from your local drive.
Choose Apple M4A from the output format list. Because M4A uses AAC, a lossy codec, you can also set the quality level before converting to control file size versus audio fidelity.
Click Convert. Convertessa extracts the audio track, re-encodes it, and writes an M4A file alongside each source 3GP file.
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. M4A stores audio as AAC, which is lossy. Before converting, set the quality level in Convertessa to control the trade-off between output file size and audio fidelity.
Yes. Drop a folder onto Convertessa or run convertessa ./folder/ --to m4a to process every 3GP file in one pass. All conversion happens on your Mac — nothing is uploaded.
Yes. Convertessa runs entirely offline. Your 3GP files are never sent to any server; everything is processed locally on your Mac.