Your files stay on your Mac.
Convertessa reads your ZIP archives and writes new .7z files entirely on your Mac — no upload, no server involved. Drop a whole folder and it converts every ZIP inside in a single pass, leaving the originals untouched.
Drag one ZIP file — or an entire folder of archives — onto Convertessa. Every file queues up automatically, ready to convert.
Pick 7-Zip from the output format list. Convertessa will write a .7z file for each ZIP in your queue.
Click Convert. Each ZIP is repacked into a .7z archive. Nothing is uploaded; all processing runs locally on 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.
Yes. Convertessa extracts every entry from the ZIP and repacks it into the .7z container. Directory structure, filenames, and file contents are preserved exactly as they were in the original archive.
Yes. Drop a folder onto Convertessa or pass a directory path on the command line — every ZIP inside is converted to a separate .7z file in one batch run.
Convertessa runs entirely offline. Your ZIP archives and the resulting .7z files never leave your Mac — no cloud service or internet connection is required.