Your files stay on your Mac.
Jupyter Notebook's .ipynb format stores code cells, markdown, and output in JSON. Convertessa reads each cell and writes it into a .muse file using Emacs Muse markup conventions. The result is a plain-text document you can open, edit, and publish directly inside Emacs.
Drag one .ipynb file or an entire folder of notebooks onto Convertessa. Mixed folders are fine — non-notebook files are left untouched.
Pick Emacs Muse from the output format list. Convertessa maps each notebook cell type — code, markdown, raw — to the matching Muse construct.
Click Convert. Each .ipynb becomes a .muse file in the same location. Conversion runs entirely on your Mac — no upload, no internet connection 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.
Each code cell is written as a Muse block, preserving indentation and content. Captured output cells are included as literal text immediately beneath the corresponding code block.
Yes. Point Convertessa at a folder and it walks every .ipynb file inside, including subfolders, and writes a matching .muse file alongside each one. Use convertessa ./notebooks/ --to muse from the terminal for the same result.
No. Convertessa converts entirely on-device. Your .ipynb files are read and written locally — no upload, no network request, no third-party server involved.