Extend cache (PDFs)

Caching

Applies cache extension to linked PDF files.

Filter extend_cache_pdfs · Filter docs

A mod_pagespeed 1.1 filter. ModPageSpeed 2.0 applies it as part of one always-on pipeline, not as a separate switch.

Both frames render identically — that's the goal. The win is in the bytes and requests below, not the look. They're served live by mod_pagespeed 1.1 on demo-httpd-1.1.modpagespeed.com; the optimized frame applies only this filter. Right after a cache purge it may briefly match the original while the worker rewrites it — reload to see the result.

Measured impact

This filter changes how the page is structured or delivered, not its size — so there's no byte or request reduction to chart. The change shows in the source diff below.

What changed in the source

The page's HTML, before and after this filter. Red lines are removed, green lines are added.


                
                  
                      … 11 unchanged lines …
                    

                        
                    

                            <ul>
                    

                              <li>Standard link to a pdf, will be cache extended:
                    

                      -          <a href="example.pdf">example.pdf</a></li>
                    

                      +          <a href="example.pdf.pagespeed.ce.syqMpgS21L.pdf">example.pdf</a></li>
                    

                              <li>Embedded pdf, will also be cache extended:
                    

                                <br>
                    

                      -         <dd><embed src="example.pdf" width="150" height="100"></li>
                    

                      +         <dd><embed src="example.pdf.pagespeed.ce.syqMpgS21L.pdf" width="150" height="100"></li>
                    

                              <li>Link to a PDF with extension ".notpdf".  It won't be cache extended
                    

                                  because a ".pdf" extension is required:
                    

                                  <a href="example.notpdf">example.notpdf</a></li>
                    

                              <li>Link to a PDF with a query parameter, will be cache extended:
                    

                      -          <a href="example.pdf?a=b">example.pdf?a=b</a></li>
                    

                      +          <a href="example.pdf,qa=b.pagespeed.ce.syqMpgS21L.pdf">example.pdf?a=b</a></li>
                    

                        
                    

                            </dl>
                    

                          </body>

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