Your files stay on your Mac.
Convertessa reads the audio track from each 3GP mobile video file and writes it as FLAC — a lossless, uncompressed format. The audio data is preserved intact; nothing is re-encoded beyond the container change. Conversion runs entirely on your Mac: no upload, no network required.
Drag individual .3gp files or an entire folder into Convertessa. The app queues every file for batch processing automatically.
Pick FLAC from the output format list. Because FLAC is lossless, the audio extracted from your 3GP files is encoded without any quality loss.
Click Convert. Convertessa processes every queued file and saves the FLAC output alongside your originals. Nothing leaves 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. FLAC is a lossless format, so the audio track extracted from your 3GP file is stored without any degradation. What was recorded is exactly what you get.
Yes. Drop an entire folder onto Convertessa or run convertessa /path/to/folder --to flac in the terminal. Every .3gp file in the folder is processed in one pass.
No. Convertessa converts files locally on your Mac. No file is ever sent to a server or over the internet at any point during conversion.