Your files stay on your Mac.
AVI is a decades-old Windows container that modern browsers, phones, and streaming platforms routinely reject. Converting to MP4 re-encodes your video into the container that plays everywhere. Convertessa does the whole job on your Mac — no upload, no account, no internet required.
Drag one AVI file or an entire folder into Convertessa. Batch mode queues every AVI it finds automatically.
Choose MP4 from the output list. Because MP4 uses lossy compression you can also set quality before you convert — higher values preserve more detail; lower values shrink the file.
Hit Convert. Convertessa re-encodes each file locally, preserving the original resolution. Output files land next to the source by default.
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.
Re-encoding is lossy, so some generation loss is unavoidable. Use the quality slider — or the --quality flag in the CLI — to control the trade-off between file size and visual fidelity. Setting quality to its maximum preserves as much detail as the source contains.
No. Convertessa runs entirely on your Mac. Files are never uploaded to any server — conversion happens locally, offline, even with no internet connection.
Yes. Drop a folder onto Convertessa or run convertessa ./folder --to mp4 in the terminal. Every AVI inside the folder is queued and converted in one pass.