Your files stay on your Mac.
DIF (Data Interchange Format) is a plain-text spreadsheet format built for moving tabular data between applications. Converting to XLSX repackages those rows, columns, and cell values into a native Excel Workbook that Microsoft Excel, LibreOffice, and Numbers open without plugins. The entire conversion runs on your Mac — no file is ever uploaded.
Drag one .dif file onto Convertessa, or drop an entire folder to queue a batch conversion in one pass.
Pick Excel Workbook (XLSX) from the output format list. Set quality to balance file size against fidelity if needed.
Click Convert. Convertessa writes each XLSX file to your chosen destination — all tabular data intact, nothing uploaded.
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 converts entirely offline. Your files are never sent to any server.
Yes. Drop a folder onto Convertessa or run convertessa ./folder/ --to xlsx to batch-convert every DIF file inside in one command.
Yes. Convertessa maps DIF cell values, row structure, and column headers directly into the XLSX format without truncation or reordering.