Your files stay on your Mac.
SGI RGB (.rgb) is a raster image format created by Silicon Graphics, common in legacy 3D and scientific imaging pipelines. Convertessa reads .rgb files directly on your Mac and converts them to AVIF, JPG, PNG, TIFF, or WebP — no server, no upload. Original resolution is preserved and EXIF metadata is stripped from every output file.
Drag a .rgb file onto Convertessa or point the CLI at it. No account or internet connection required.
Pick AVIF, JPG, PNG, TIFF, or WebP from the output list.
Convertessa writes the converted file alongside the original. Nothing leaves your machine.
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 runs entirely on your Mac — SGI RGB files are read and converted locally. Nothing is uploaded to a server at any point.
Convertessa converts .rgb files to AVIF, JPG, PNG, TIFF, and WebP. Choose the target in the app or pass --to <format> on the command line.
Yes. Point Convertessa at a folder and it converts every .rgb file inside. On the command line: convertessa ./folder/ --to png handles the whole folder in one step.