Your files stay on your Mac.
3GP is the container format recorded by mobile cameras. Converting to AC-3 extracts the audio track and re-encodes it as Dolby Digital — the codec used by Blu-ray discs, AV receivers, and broadcast systems. Every file stays on your Mac: Convertessa runs entirely offline, no upload required.
Drag one file or an entire folder of 3GP clips onto Convertessa. Batch mode processes every file in a single pass.
Choose AC-3 from the output format list. Use the quality slider to match the fidelity your target system requires.
Click Convert. Convertessa extracts the audio and writes AC-3 files alongside the originals — no server, no wait.
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.
Convertessa extracts the audio track and writes a standalone AC-3 file. The original 3GP file is left untouched.
Yes. Drop a folder onto the app or run convertessa /path/to/folder --to ac3 in the terminal. Every 3GP file in the folder is converted in one pass.
AC-3 is a lossy format, so quality controls the trade-off between file size and fidelity. For home-theatre or broadcast use, a high quality setting is recommended. For speech-heavy mobile recordings, a medium setting is usually transparent.