Your files stay on your Mac.
Converting AVI to Matroska MKV rewraps your video and audio streams into a modern, flexible container. MKV supports multiple audio tracks, chapters, and embedded subtitles that AVI cannot carry. The conversion runs entirely on your Mac — no upload, no account required.
Drag one AVI file or a whole folder onto Convertessa. Batch mode picks up every AVI it finds with no extra setup.
Choose Matroska MKV from the output list. Because MKV supports lossy encoding, you can also set quality to control the balance between file size and fidelity.
Click Convert. Convertessa writes the MKV files on your Mac. Nothing is uploaded — your originals stay untouched.
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. Pass a folder path to Convertessa and it converts every AVI file inside. Use convertessa /path/to/folder --to mkv from the command line, or drop the folder onto the app.
No. Convertessa runs entirely on your Mac. Files are read and written locally — nothing is sent to a server or cloud service.
Yes. Matroska MKV supports lossy encoding, so you can set the quality level before converting to balance file size against visual fidelity.