Your files stay on your Mac.
Convertessa extracts your ZIP archive and writes the same file tree into a TAR layer, then Gzip-compresses the result. The output is a standard .tar.gz that Linux and macOS toolchains expect. The entire operation runs offline — files never leave your Mac.
Drag a single .zip archive or an entire folder into Convertessa. Every ZIP in the folder is queued automatically for batch conversion.
In the output format list, choose TAR + Gzip (.tar.gz). Convertessa never pre-selects a format — you pick the target explicitly.
Click Convert. Convertessa repacks each archive and writes a .tar.gz beside the original — entirely offline, no upload required.
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 reconstructs the exact entry tree from the ZIP inside the TAR layer before Gzip compression is applied. No paths are flattened or renamed.
Yes. Drag the folder onto Convertessa and every .zip inside is converted to .tar.gz in a single batch. Each output file is written next to its source archive.
No. Convertessa runs entirely on your Mac. Your ZIP files are never uploaded to a server or sent over the network — the conversion happens locally.