Your files stay on your Mac.
AVCHD MTS files from camcorders and action cameras carry a full audio track alongside the H.264 video. Convertessa extracts that track and writes it to a WAV file — uncompressed, full resolution, with no lossy re-encoding. The result drops straight into any audio editor or DAW.
Drag one .mts clip or an entire folder of footage onto Convertessa. Batch mode processes every file in one pass.
Pick WAV from the output format list. Convertessa extracts the audio track at its original resolution — no re-compression, no quality loss.
Click Convert. WAV files appear alongside your originals. Source clips are never modified and never leave 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.
It extracts whichever audio track the MTS container carries — typically AC-3 (Dolby Digital) or PCM — and writes it to WAV at its original sample rate and bit depth. No re-sampling or re-encoding is applied.
No. WAV is uncompressed, so the output is a lossless representation of the source track. Any quality ceiling comes from the original recording, not the conversion.
Yes. Drop the folder onto Convertessa or point the CLI at the directory (convertessa ./footage --to wav) and every .mts file is converted in a single batch run.