Multi-language Ebook Formatting
Quick Answer: Formatting an ebook in a different language involves more than swapping the text. Right-to-left languages (Arabic, Hebrew, Persian) require structural changes to the EPUB file. CJK languages (Chinese, Japanese, Korean) need appropriate fonts and may use vertical text. All translated ebooks need updated metadata (language tags, description, title) in the target language. Testing on multiple devices is critical because non-Latin scripts render inconsistently across e-readers.
Most ebook formatting guides assume English or another left-to-right Latin-script language. The moment you step outside that assumption, new technical challenges appear. This article covers what changes when formatting ebooks for different language markets.
Right-to-Left (RTL) Languages
Arabic, Hebrew, Persian (Farsi), and Urdu read right to left. Formatting an ebook in these languages requires changes beyond translating the text.
Page progression direction. In a standard EPUB, pages flow left to right. For RTL ebooks, the page progression must be set to right-to-left in the EPUB's OPF file. This means the reader opens the book from what an English reader would consider the "back" and progresses toward the "front."
Text direction. Every content element needs the dir="rtl" attribute set in the HTML. Paragraph alignment switches to right-aligned by default. Lists, block quotes, and other structural elements need matching directional settings.
Bidirectional text. If your RTL ebook includes English words, brand names, URLs, or technical terms, the formatting needs to handle bidirectional (BiDi) text, where LTR content appears within an RTL flow. EPUB 3 supports BiDi text through Unicode bidirectional algorithm markers, but rendering varies across e-readers. Testing is essential.
Font support. Not all fonts include Arabic, Hebrew, or Persian glyphs. Embed a font that fully supports your target script, or specify fallback fonts that do. Noto Sans Arabic (free, from Google) and Amiri (free, open-source) are reliable choices for Arabic text.
Most standard ebook formatting tools (Atticus, Vellum) have limited RTL support. Specialized tools like Doc Book Maker, Sigil (free EPUB editor), and manual EPUB construction with a text editor are more reliable for RTL ebooks.
CJK Languages (Chinese, Japanese, Korean)
Chinese, Japanese, and Korean present their own formatting considerations.
Character sets. CJK scripts use thousands of characters. Font files for these languages are significantly larger than Latin-script fonts, which affects ebook file size and delivery costs. Use system fonts where possible to avoid embedding large font files.
Vertical text (Japanese). Some Japanese books use vertical text layout (tate-gaki), where text runs from top to bottom, right to left. EPUB 3 supports vertical writing through the writing-mode: vertical-rl CSS property. Kindle and Apple Books both support vertical Japanese text, but implementation quality varies. Many Japanese ebooks use horizontal text (yoko-gaki) to avoid inconsistencies across devices.
Ruby text (Japanese). Small phonetic annotations (furigana) above or beside kanji characters are common in Japanese books. EPUB 3 supports ruby text through HTML <ruby> and <rt> tags. Verify that ruby text renders correctly on target devices, as some e-readers handle it poorly.
Line breaking rules. CJK text has specific rules about where lines can break (for example, certain punctuation marks should not appear at the beginning of a line). CSS properties like word-break and line-break help control this, but default e-reader behavior may override your settings.
Metadata for Translated Ebooks
Every translated ebook needs updated metadata in the target language.
Language tag. The <dc:language> tag in the EPUB's OPF file must reflect the target language (for example, es for Spanish, de for German, ja for Japanese). Amazon KDP, Apple Books, and other platforms use this tag to categorize and index the book.
Title and description. The book title and description should appear in the target language on the product listing. On Amazon KDP, you create a separate listing for each language edition, with the title, subtitle, description, and keywords all in the target language.
ISBN. Each language edition is technically a different product and should have its own ISBN if you use ISBNs. An English edition and a Spanish edition of the same book need separate identifiers.
Categories and keywords. Research categories and keywords in the target language marketplace. What works in the US Kindle Store may not match the categories available in the German, Japanese, or Spanish Amazon stores.
What Good Multi-language Formatting Looks Like vs What Does Not
Works well: - The translated ebook has been tested on at least three devices or apps (Kindle, Apple Books, and a phone) to verify that text, fonts, and layout render correctly in the target script. - Metadata is fully updated in the target language: title, description, language tag, and keywords all match the translated content. - RTL or CJK-specific formatting requirements have been addressed at the EPUB structural level, not just in the visible text.
Red flags: - The translator delivered the text, and the author simply pasted it into their existing English EPUB template without updating language tags, text direction, or metadata. This produces an ebook that looks broken on most devices. - Non-Latin characters display as boxes, question marks, or garbled symbols. This is a font support issue, resolvable by embedding an appropriate font or specifying one with complete coverage of the target script. - The table of contents still shows English chapter titles while the body text is in the target language. Every navigational element needs translation.
The Takeaway
Multi-language ebook formatting adds a layer of technical complexity beyond standard English formatting. RTL languages need structural EPUB changes. CJK languages need font and layout considerations. Every translation needs fully updated metadata. Test extensively on real devices before publishing, because non-Latin scripts render inconsistently across e-readers. For the full process, see the Ebook Translation and Localization guide.
Q: Can standard ebook formatting tools handle non-English languages? A: Most tools (Atticus, Vellum, Reedsy Book Editor) handle European languages and other left-to-right scripts well. RTL languages (Arabic, Hebrew) and vertical CJK text require specialized tools or manual EPUB editing. Sigil (free) and Doc Book Maker are more reliable for these cases.
Q: Do you need a different ISBN for each language edition? A: Yes. Each language edition is considered a separate product and should have its own ISBN if you use ISBNs. On Amazon KDP, each language edition is a separate listing with its own ASIN.