Your files stay on your Mac.
AVCHD MTS is the native recording format used by Sony and Panasonic camcorders. Converting to iTunes M4V packages the video in an Apple-compatible container that plays in iTunes, Apple TV, and iOS. Convertessa handles the conversion entirely on your Mac — your footage never leaves your device.
Drag one MTS clip or an entire camcorder folder into Convertessa. Batch mode processes every clip in a single pass, preserving the original resolution of each file.
Choose iTunes M4V from the output list. Because M4V uses lossy compression, you can set quality to balance visual fidelity against file size before converting.
Click Convert. Convertessa runs entirely offline — no internet connection required — and saves the M4V files alongside your originals.
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. M4V is iTunes' native video container. Once converted, files appear in your library and sync to Apple TV and iOS devices without further steps.
No. All conversion happens locally on your Mac using offline processing. Your AVCHD footage never leaves your device.
Yes. Point Convertessa at the folder and it batch-converts every MTS file inside, preserving the original resolution of each clip.