Most PDFs remain relatively small, short documents. Encryption is uncommon and generally does not prevent document access. Accessibility text extraction is enabled in most encrypted documents, although a significant minority still disables it. PDF 1.7 continues to dominate document production. Proprietary extensions remain common, particularly in annotation workflows. Link annotations dominate all other annotation types combined.
> Because Common Crawl stores only the first 1 MB of each PDF
That limit became 5 MB in March 2025.
The final dataset contains:
20,578,394 PDF documents approximately 38 TB of source data
basic metadata: page count file size creation and modification dates PDF version (including Version entry in the document catalog) producer and creator encryption information and permissions annotations presence of interactive forms presence of optional content layers presence of digital signatures image only (scanned) pages Tagged PDF information: stats on the use of structure element types logical structure tree validation against ISO 32005