[Skip navigation links]

Quirks Mode Statistics

This page shows proportion of pages using quirks mode for sites submitted to the online demo. Pages using quirks mode are becoming less common: under 10% of pages today, compared with more than 40% in 2008.

Quirks Mode Pages

Graph: about 10% of pages render in quirks mode

Percentage of pages with quirks mode DOCTYPEs.

What is Quirks Mode?

Older web pages don't usually meet W3C standards, so browsers have to display them using "best effort". This often contradicts W3C standards, so modern browsers display pages using two methods:

Note: Data is anonymized and aggregated to show averages. No site specific data is ever shown.