PageSpeed Service was turned off on August 3rd, 2015. Please see Turndown Information for PageSpeed Service.
To speed up web pages by partially caching HTML.
This is an aggressive rewriter, so please preview your site as described here, to ensure that it works for your site before making it live.
This rewriter renders the visible content much sooner by making HTML cacheable. HTML is typically not cached because small portions of the page are non-cacheable due to personalized content. Non-cacheable portions are stripped from the HTML, and the rest of the page is cached on PageSpeed servers.
Configuring the rewriter
You need to provide the non-cacheable parts as input to configure the rewriter
as shown below
Non-cacheable parts identify the portions of the page that are not cached on PSS servers. It is specified using
attributes in the HTML. For the configuration shown, any HTML tags with id="username"
to be marked as non-cacheable.
Let's look at a sample page of an ecommerce site and see how to identify non-cacheable portions on the page. In this page the non-cacheable portions are username and price. If we look at the HTML page source, they appear in the page as
<span id="username"> firstname.lastname@example.org </span> <span class="price"> $100 </span>
These non-cacheable portions should be specified as id=username,class=price.
The effect of this rewriter on this page can be observed before and after rewriting. In this example, an intentional delay of a few seconds has been added to the non-cacheable portions so you can observe that they are rendered later.
- PSS fetches the web page from your origin servers, stamps out the portions marked as non-cacheable and caches the restp.
- When a user visits your site, the browser requests the page from PSS.
- In parallel, PSS requests the HTML web page from your origin site.
- PSS extracts only the non-cacheable portions from the full HTML and sends it to the browser.
- This rewriter doesn’t work if different content is served for the same URL based on cookies, IP, etc.
- This rewriter works on modern desktop browsers - IE9, Firefox 3+, Chrome, Safari. It is not applied on pages served for other user agents such as mobile devices and tablets.
- If some users are seeing admin panels or personalized content for other users, your specification of non-cacheable portions is incomplete. You need to mark those portions as non-cacheable.
- If you have a problem with this rewriter, turn off the rewriter and then contact us by email at email@example.com.