Dual Lab announces the release of PDF4WCAG Accessibility Checker 1.12. The release introduces improvements to accessibility and keyboard navigation, error visualization, validation accuracy, localization to Korean language and application stability.
PDF file sizes follow an approximately log-normal distribution, making logarithmic visualization and median-based statistics more appropriate than arithmetic averages.
Median file size increased steadily until approximately 2021, after which growth flattened and became slightly negative.
Quadratic regression confirms that this slowdown is highly statistically significant.
The evidence suggests that the typical PDF published on the web has not become substantially larger over time.
Despite initial guesses, Tagged PDFs turn out to be smaller in average than Untagged ones. https://pdf4wcag.com/blog-news/analysis-pdf-file-size
This first part of the June 2026 Common Crawl PDFs analysis reveals several long-term characteristics of PDF usage on the public web:
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.
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
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