Your files stay on your Mac.
Convertessa reads each OPML outline element and maps it to the corresponding JATS XML tag — sections, titles, and nested content land in the right place in the article hierarchy. The conversion runs entirely on your Mac; no file is sent to any server. Drop a single .opml file or point it at a folder to process the whole batch at once.
Drag one or more .opml files onto Convertessa, or select a folder to queue every OPML file inside it.
Choose JATS XML from the output format list. Convertessa will map each OPML outline element to the appropriate JATS article element before writing the file.
Click Convert. JATS XML files are written alongside your originals. Everything stays on your Mac — nothing is 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.
Convertessa preserves the nesting depth of your OPML source and maps each level to the appropriate JATS <sec> and <title> elements, so the hierarchy in your outline is reflected in the output document.
Yes. Drag a folder onto Convertessa or run convertessa ./folder/ --to jats in the terminal to convert every OPML file inside in a single pass.
No. Convertessa runs entirely offline on your Mac. Your OPML files are read and written locally; nothing leaves your machine.