Your files stay on your Mac.
Convertessa runs each EPUB through Calibre: unpacking the archive, following the spine for reading order, and typesetting the book into a fixed-page PDF whose bookmark outline comes from the table of contents. Text stays selectable, images ride along, and you choose the quality value that governs how that artwork is encoded onto the page. Drop a whole library folder and convert it in one pass, entirely on your Mac.
An EPUB is a ZIP archive with strict contents: XHTML documents holding the text, CSS for styling, images, often embedded fonts, and an OPF package file listing the metadata and the spine — the order those documents are meant to be read in. Nowhere inside is there a page. A reading app invents pages at display time from your screen size and chosen typeface, which is why the "page 214" on your phone is not the page anyone else is looking at.
PDF is the opposite kind of object: a fixed canvas with content pinned to coordinates. So this conversion does not translate pages, it manufactures them. Calibre lays the book's XHTML out once, at one page size with one font stack, and freezes the result. Everything you gain and everything you lose follows from that single decision.
The failure that surprises people most is DRM. Books bought from most stores are encrypted with Adobe ADEPT or a shop-specific scheme, and an encrypted EPUB cannot be read by any converter — the archive opens, but the content documents inside are ciphertext. That is DRM working exactly as intended rather than a defect in the app. Titles from Standard Ebooks, Project Gutenberg, publisher direct downloads and your own exports convert without complaint.
Drag one EPUB or a folder of several hundred onto the queue. Each archive is unpacked locally, its OPF spine read for reading order and its navigation document read for the table of contents.
PDF is a lossy target here, because artwork from the EPUB is encoded again as it lands on the page. Raise quality for illustrated books and comics; lower it for novels where the cover is the only image.
Calibre typesets each book and writes the PDF beside it. Open the sidebar in Preview and confirm the chapters arrived as outline entries before you archive or delete the source EPUB.
Images, audio, video, documents, archives, eBooks and fonts — 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.
Because a PDF carries its own typesetting. The EPUB was a ZIP of compressed XHTML that a reader laid out on the fly; the PDF stores every glyph position, embeds the fonts it needed and holds re-encoded images. A 400 KB novel routinely becomes several megabytes, and an illustrated title far more. Lowering the quality value shrinks the image data, but embedded fonts and layout objects are a floor you cannot get below.
There are none to keep. An EPUB stores no pages at all — your reader generated "page 214 of 480" from your screen dimensions and font size, and changing either renumbers the whole book. The PDF gets its own pagination, created during typesetting, and it will not match your Kindle, your Kobo, your phone or the printed edition. When the source is an ebook, cite by chapter and section rather than by page.
Check them before trusting them. EPUB 3 encodes maths as MathML, and rendering support for MathML is uneven, so a formula-dense textbook can come through with misplaced fractions, missing operators or fallback glyphs. Equations the publisher supplied as images convert reliably, since they are simply artwork. If you are converting a technical title, open the most formula-heavy chapter of the PDF first — that is where breakage shows.
Two causes cover nearly every case. First, DRM: a store-encrypted book cannot be decoded by any converter. Second, and more common than people expect, the file is not a book — an .acsm is an Adobe fulfilment token of a few kilobytes that tells a reader app to download the real book. Check the size in Finder: anything under about 20 KB is a token or a stub, not an EPUB.
More predictably than reflowable ones. A fixed-layout EPUB already declares page dimensions and positions its content absolutely, so its pages map to PDF pages roughly one to one instead of being invented. Because those books are essentially full-bleed artwork, the quality value matters far more than it does for a novel: keep it high, and expect a PDF several times the size of the EPUB. Guided panel-by-panel reading is a reader feature and does not carry over.
Calibre files books in per-author, per-title subdirectories, so point the CLI at the library and send the results somewhere flat:
convertessa ~/Calibre\ Library --to pdf --quality high -o ~/Documents/PDF
Or drop the folder onto the window. Output names follow the source filenames rather than the titles in Calibre's database, so a tidily named library converts into tidily named PDFs.
Yes. The text is written as real text objects with embedded fonts, so Preview, Acrobat and Books can select it, search it and attach highlights and notes exactly as they would on any born-digital PDF. No OCR is involved, because nothing was flattened into an image — this is not a scan. The one wrinkle is copying from justified, hyphenated text, where line-break hyphens sometimes come along for the ride.