Your files stay on your Mac.
AVI is an older container format expected by legacy players, editing tools, and hardware that can't handle MP4. Converting your MP4 to AVI rewraps the video stream into the AVI container so it plays wherever AVI is required. You can set output quality before converting — everything runs on your Mac, nothing is uploaded.
Drag one MP4 file or an entire folder into Convertessa. All processing runs locally — files never leave your Mac.
Choose AVI from the output list. Set quality to control the balance between visual fidelity and file size.
Click Convert. Convertessa rewraps each file into AVI at the quality you set, preserving the original resolution.
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. Convertessa preserves the original resolution when converting MP4 to AVI.
Yes. Drop a folder onto Convertessa or use the command line: convertessa *.mp4 --to avi. Every MP4 in the folder is converted in one pass.
AVI uses lossy encoding, so the quality setting controls the trade-off between visual fidelity and file size. Higher quality produces larger files; lower quality produces smaller files with more visible compression artifacts.