Your files stay on your Mac.
Convertessa reads each EPUB's chapters, text, and embedded images and rewrites them as a single FictionBook (.fb2) XML document. The output preserves heading structure and inline images in a format compatible with readers like FBReader and PocketBook. Every file is processed locally — nothing is uploaded.
Drag one file or an entire folder of EPUBs onto Convertessa. Batch mode processes every .epub in the folder in one pass.
Choose FictionBook from the output list. If your EPUBs contain embedded images, you can also set quality for those images at this step.
Hit Convert. Convertessa writes .fb2 files alongside the originals — or to any output folder you choose — without touching your source files.
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.
Yes. Pass the folder path on the command line (convertessa ./books/ --to fb2) or drag the folder onto Convertessa in the app. Every .epub inside is converted in a single batch.
Yes. Convertessa strips embedded metadata from the output .fb2 file, so document-level identifiers and other metadata from the original EPUB are not carried over.
Convertessa maps EPUB's spine and navigation points to FictionBook sections, so chapter headings and the book's hierarchy are preserved in the .fb2 output.