PDF default language

Silktide checks that each of your PDF documents declares its main language. The main language is a document-level property (for example English, or French) that tells software how the text should be read. It is separate from any language the text visibly happens to be written in.

Why this matters

Screen readers use the declared language to choose a voice and pronounce words correctly. A French document read aloud with English pronunciation rules is very hard to follow. Other tools, such as spell checkers, hyphenation and translation, rely on the same property.

How to fix it

1. Fix it at the source where possible: set the document language in the original Word, Google Docs, or InDesign file, then export it as a tagged PDF.
   • Word: set the proofing language (Review → Language), and keep "Document structure tags for accessibility" on when saving as PDF.
   • Google Docs: File → Language, then download as PDF.
2. Alternatively, set it in a PDF editor such as Adobe Acrobat Pro: File → Properties → Advanced → Reading Options → Language.
3. Use a standard language tag such as en, en-US, fr or es-ES.
4. For multilingual documents, set the main language for the whole document, and mark passages in other languages separately.

How Silktide tests this

1. Open each PDF document found on your website.
2. Read the document's declared language from its catalog, falling back to its document information and its structure tree.
3. Report the document if no language is declared anywhere.

This check looks for the presence of a language, not its validity. A document that declares a malformed language tag still passes here.

Learn more

• Understanding Success Criterion 3.1.1: Language of Page (WCAG 2.2)
• Technique PDF16: Setting the default language using the /Lang entry in the document catalog (WCAG)