How to Convert PDF to a Reflowable EPUB 3 Ebook

Understand the change from fixed pages to reflowable text

A PDF page has fixed dimensions and positions. Text, diagrams, tables, headers, and footers are arranged for that page size. A reflowable EPUB is different: the reading system lays out structured XHTML for the current screen, font size, margins, and user preferences.

PDFStack uses a text-first conversion. It extracts readable text from each PDF page, creates one XHTML chapter for every source page, adds an EPUB navigation document, manifest, spine, identifier, title, language, optional author, and modification timestamp, then packages those resources as an EPUB file. It does not reproduce the PDF page as a fixed visual image.

Check whether the PDF has usable text

Try selecting and copying a sentence in a PDF viewer. If the result is accurate and in a sensible order, the file probably has a useful native text layer. PDFStack prefers that text because it is faster and usually more accurate than recognizing pixels.

Scanned or image-only pages use browser OCR. Recognition can misread small characters, unusual fonts, handwriting, columns, mathematical notation, or low-contrast scans. Choose English, Arabic, or English plus Arabic recognition to match scan content, and plan to review the extracted text.

• ✓Use native text when it is available.
• ✓Choose OCR language for scan-like pages, not for EPUB display metadata.
• ✓Check columns, tables, footnotes, and headers carefully.
• ✓Keep the source PDF as the fixed-layout reference.

Set title, author, and language metadata

The ebook title defaults to the PDF filename without its extension. For one-file conversion, you can provide a cleaner title. Author is optional and should be entered only when it is known; PDFStack does not infer authorship from the document.

Set the EPUB language using a BCP 47 tag such as en, en-GB, ar, or fr. This value is written into the package metadata and chapter language attributes so reading systems and assistive technology can interpret the publication more appropriately. It does not change OCR recognition; that is a separate setting.

Convert and preview the extracted reading order

Add one PDF or a batch and begin conversion. The pipeline inspects every page, uses native text where it is sufficient, and invokes OCR only where needed. Each PDF becomes its own EPUB; multiple results can be downloaded together as a ZIP.

The preview displays the text that feeds the ebook. Read across page boundaries and look for repeated headers, footer numbers, broken words, reordered columns, missing symbols, and OCR substitutions. Page boundaries become separate chapters labelled Page 1, Page 2, and so on.

Know what the current EPUB contains

The EPUB contains text paragraphs split from extracted page text, a page-based table of contents, ordered spine items, and basic metadata. It does not currently embed PDF images, recreate tables, preserve fonts, copy hyperlinks, generate a cover, infer semantic headings, or reproduce the original page design.

That limited structure is useful for text-first reading, searching, and later editorial work. A publication-ready commercial ebook normally needs additional editing: meaningful chapter titles, paragraph cleanup, heading hierarchy, cover artwork, CSS, image descriptions, publisher metadata, and quality assurance.

Validate in real reading systems

Open the download in at least two reading systems when compatibility matters. Change font size and viewport width, follow the table of contents, inspect chapter order, search for distinctive terms, and verify punctuation and non-Latin scripts.

For formal distribution, run the file through EPUBCheck, the official conformance checker maintained on behalf of W3C. Conformance is only one part of quality: editorial accuracy, semantic structure, accessibility, and reading-system behavior still need human review.