To embed fonts in your book PDF means to include the font data inside the file itself, so KDP’s printing system reads your chosen typefaces exactly as you designed them. If any font in your interior or cover PDF is not embedded, KDP may reject the file outright or substitute a different font, shifting line breaks, page counts, and the overall look of your book. You can verify embedding in the free Adobe Acrobat Reader by opening File > Properties > Fonts.
- What Does It Mean to Embed Fonts in a PDF?
- How Do You Check Whether Fonts Are Embedded in Your PDF?
- What Is the Difference Between “Embedded” and “Embedded Subset”?
- Why Do Some Fonts Refuse to Embed?
- How Do You Fix Unembedded Fonts in Word, InDesign, and Other Tools?
- When Should You Outline Fonts Instead of Embedding Them?
- Frequently Asked Questions
What Does It Mean to Embed Fonts in a PDF?
Embedding a font means storing a copy of the font’s character data directly inside your PDF file. When KDP’s print system opens your uploaded PDF, it does not look for fonts installed on its own servers; it reads the font data packaged within the file. If that data is missing, the system either rejects the upload or substitutes a default font, which almost always changes line lengths, paragraph breaks, and page counts.
KDP’s paperback font requirements state that authors should embed all fonts in interior and cover files prior to submission. The requirement applies to every font in the document: body text, headings, page numbers, chapter titles, and any decorative or display type. Even fonts that seem standard (like Times New Roman or Arial) need to be embedded, because KDP’s production environment does not assume any fonts are pre-installed.
Think of it this way: your PDF is a self-contained package that travels to a print facility. If the package does not include everything the printer needs, something will go wrong. Font embedding is the step that makes the package complete.
How Do You Check Whether Fonts Are Embedded in Your PDF?
You can check font embedding status using the free Adobe Acrobat Reader; you do not need the paid Acrobat Pro for this step. Open your PDF in Acrobat Reader, then go to File > Properties (on Mac, this is under the Acrobat Reader menu or via Cmd+D). Click the Fonts tab. This displays every font used in the document along with its embedding status.
Each font in the list will show one of three statuses:
- Embedded — the entire font file is included in the PDF. This is the ideal status.
- Embedded Subset — only the characters actually used in the document are included. This is usually acceptable (more on this below).
- No label after the font name — the font is not embedded. This is the problem. Any font without an “Embedded” or “Embedded Subset” tag will cause issues at upload.
Go through the entire list. If even one font shows no embedding status, your file needs to be re-exported with that font embedded. A common trap: authors check only the body font and miss an unembedded font used in a single header, a footnote, or a page number style.
What Is the Difference Between “Embedded” and “Embedded Subset”?
A fully embedded font includes every character in the typeface’s character set, whether your document uses them or not. An embedded subset includes only the specific characters that appear in your document. For a 200-page novel using Garamond, a subset might include 80 or 90 glyphs out of the font’s full 600-plus character set.
KDP’s help documentation states that it recommends fonts be “fully embedded, rather than embedding as subsets.” In practice, KDP accepts both “Embedded” and “Embedded Subset” files without rejection. The recommendation for full embedding is precautionary: if you later need to make minor text edits in Acrobat and a character you need is not in the subset, the edit will fail silently or produce a visible substitution.
For most self-published authors, embedded subsets are fine. The file size difference can be significant; subsetting a font-heavy document with 15 different typefaces might save 10 to 20 MB compared to full embedding. If you are producing a final, print-ready PDF that you do not plan to edit further in Acrobat, subsetting is a practical choice. If you want maximum safety and do not mind slightly larger files, choose full embedding in your export settings.
Why Do Some Fonts Refuse to Embed?
The most common reason a font refuses to embed is a licensing restriction set by the font’s creator. Every font file contains a metadata field called the “embedding permission” flag, and software like Word, InDesign, and Affinity Publisher reads this flag before allowing the font to be included in a PDF. If the flag says “no embedding” or “print and preview only,” your design software will either skip the font during export or display a warning.
Fonts downloaded from free font websites are frequent offenders. Many are labelled “free for personal use,” which typically means you can use them on screen but cannot embed them in a commercial PDF. The distinction matters: using a font to design something on your computer is one thing; packaging that font’s data inside a file you distribute (or send to a printer) is another. Some paid fonts also restrict embedding unless you purchase an extended licence.
If you encounter a font that will not embed, you have two practical options. First, you can replace it with a font that has permissive licensing. Google Fonts are an excellent fallback: every font in the Google Fonts library is open source, released under the SIL Open Font License, and explicitly allows embedding in PDFs, commercial use, and print publishing at no cost. Alternatives like EB Garamond, Libre Baskerville, Lora, and Source Serif Pro are typographically strong replacements for common book fonts. Second, if replacing the font is not an option (for example, a client’s branding requires a specific typeface), you may need to purchase an embedding-compatible licence from the font vendor.
How Do You Fix Unembedded Fonts in Word, InDesign, and Other Tools?
The fix depends on which application you used to create your book interior. Here are the steps for the most common tools self-published authors use.
Microsoft Word
Word can embed fonts at two stages: in the document itself and during PDF export. For document-level embedding, go to File > Options > Save, then check “Embed fonts in the file” under “Preserve fidelity when sharing this document.” Uncheck “Embed only the characters used in the document” to get full embedding rather than a subset. Also uncheck “Do not embed common system fonts” so that standard fonts like Times New Roman are included.
When exporting to PDF, go to File > Save As (or Export), choose PDF, and click Options. Check “ISO 19005-1 compliant (PDF/A)” to force font embedding in the output. PDF/A is a stricter archival format that requires all fonts to be embedded; KDP accepts PDF/A files without issue. After export, verify in Acrobat Reader that all fonts show “Embedded” or “Embedded Subset.”
Adobe InDesign
InDesign embeds fonts automatically when you export to PDF, provided the font’s licence permits it. For book interiors, export using the PDF/X-1a:2001 preset (File > Adobe PDF Presets > PDF/X-1a:2001). This preset embeds font subsets by default, converts all colours to CMYK, and flattens transparency: exactly what KDP’s print workflow expects.
To ensure full embedding rather than subsetting, open the export dialog, go to the Advanced panel, and set “Subset fonts when percent of characters used is less than” to 0%. This forces InDesign to embed the complete font regardless of how many characters your document uses. If InDesign displays a warning icon next to a font during export, that font has a licensing restriction. Check it via Type > Find Font, select the problem font, and click More Info to see the restriction details.
Affinity Publisher
When exporting to PDF, choose the PDF/X-1a preset. Affinity Publisher embeds all fonts by default when using this preset. If a font cannot be embedded due to licensing, Affinity will display a warning during export. Replace the restricted font before proceeding.
LibreOffice Writer
Go to File > Export as PDF. In the General tab, check “Embed all fonts” (available in LibreOffice 7.0 and later). For older versions, you can also check “Archive (PDF/A-1a)” which forces font embedding. LibreOffice handles most open-source fonts well, but some system fonts may not embed if they carry restrictive licences.
Formatting tools (Vellum, Atticus, Kindle Create)
Dedicated book formatting tools like Vellum, Atticus, and Kindle Create embed fonts automatically during export. If you are using one of these tools and your fonts are from the tool’s built-in library, embedding is handled for you. If you have imported a custom font, the same licensing rules apply: the font must permit embedding, or the export will either skip it or produce a warning.
When Should You Outline Fonts Instead of Embedding Them?
Outlining (also called “converting to outlines” or “converting to curves”) transforms each letter from editable font data into a vector shape. The resulting PDF no longer contains any font data at all; every character is a graphic. This eliminates embedding issues entirely, because there is no font left to embed or refuse embedding.
However, outlining should be treated as a last resort for book interiors, not the default workflow. Outlined text is no longer searchable or selectable, which hurts accessibility and makes the PDF harder to work with after export. The typographic quality can also degrade slightly, because outlined glyphs lose the hinting instructions that fonts use to render cleanly at small sizes. For a 300-page novel set in 11-point type, this degradation may be visible.
Outlining is appropriate in two narrow scenarios: when a single decorative font on a cover or title page refuses to embed and you cannot find an acceptable replacement, or when a print service specifically requests outlined files (KDP does not). For body text in a book interior, always embed rather than outline. If a body font will not embed, replace it with one that will; the font selection process is a better investment of time than converting an entire manuscript to outlines.
Frequently Asked Questions
Do I need Adobe Acrobat Pro to check font embedding, or does the free Reader work?
The free Adobe Acrobat Reader is sufficient. Open your PDF, go to File > Properties, and click the Fonts tab. Every font in the document will be listed with its embedding status. You do not need a paid subscription to view this information.
Will KDP reject my file if fonts are embedded as subsets instead of fully embedded?
No. KDP accepts both “Embedded” and “Embedded Subset” fonts. KDP’s documentation recommends full embedding as a best practice, but subset embedding does not trigger a rejection. The only status that causes problems is a font with no embedding at all.
What happens if I upload a PDF with an unembedded font to KDP?
KDP’s file review will flag the issue. In some cases the upload is rejected outright with an error message referencing fonts. In other cases KDP substitutes a default font, which changes line breaks and page counts, producing a printed book that looks noticeably different from your intended design.
Are Google Fonts safe to use in a print book PDF?
Yes. Every font in the Google Fonts library is released under an open-source licence (the SIL Open Font License) that explicitly permits embedding in PDFs, commercial use, and print publishing. There is no cost and no attribution requirement in the printed book itself.
Does the font embedding requirement apply to cover files as well as interior files?
Yes. KDP requires all fonts to be embedded in both interior and cover PDFs. Cover files often use display or decorative fonts that are more likely to have licensing restrictions, so check the cover PDF separately after export.
