Your files stay on your Mac.
AMR is a narrow-band codec built for voice calls; converting it to FLAC re-encodes the audio into a lossless container with no further quality loss. The original waveform is preserved exactly as captured. Everything runs on your Mac — no file is ever uploaded.
Drag one AMR recording or an entire folder onto Convertessa. Batch mode queues every .amr file at once so you can process a full archive in a single pass.
Choose FLAC from the output format list. Because FLAC is lossless there is no quality slider — the full audio data is always written to the output file.
Click Convert. Convertessa processes everything locally and places the FLAC files alongside the originals. Metadata is stripped from each output 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.
No — and that is the point. FLAC is lossless, so the conversion captures exactly what is in the AMR file without introducing additional compression artefacts. Quality cannot exceed the original AMR source, but it will not degrade further either.
Yes. Drop a folder onto Convertessa or run convertessa ./folder/ --to flac in the terminal. Every AMR file in the folder is converted in one pass.
No. Convertessa runs entirely offline on your Mac. Files never leave your machine at any point during conversion.