Your files stay on your Mac.
Convertessa reads your .xlsx Excel Workbooks and writes them as .ods OpenDocument Sheet files—the native format of LibreOffice Calc and compatible open-source office suites. Every step runs locally on your Mac; no file is uploaded or transmitted. Convert a single workbook or drop an entire folder to process every .xlsx at once.
Drag one .xlsx file or a whole folder onto Convertessa. The app reads each workbook's sheets, data, and formatting entirely on your Mac—no internet connection needed.
Pick OpenDocument Sheet from the output list. Set quality to match your needs, then confirm any per-file options before proceeding.
Click Convert. Convertessa writes a matching .ods file for each source workbook, stripping embedded metadata and preserving resolution throughout.
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.
Convertessa passes the workbook structure through as written. Formula compatibility in the resulting .ods depends on how closely the target application—such as LibreOffice Calc—supports the Excel function set; the converter does not alter or drop formulas during conversion.
Yes. Drop the folder onto the app window or run convertessa ./folder/ --to ods. Convertessa processes every .xlsx file inside and writes a sibling .ods file for each one.
No. Convertessa runs fully offline. Your .xlsx files are read and written on your Mac; nothing is transmitted to an external server at any point.