Page Speed’s rewriter is done before the unoptimized version even starts loading images. Image: Screenshot/Webmonkey
Google has added yet another trick to the company’s Page Speed web optimization service — a page rewriter that turbocharges your site by making sure that your visible, above-the-fold content loads before anything else.
Google started on its web optimization quest with the Page Speed browser extension, then it moved the Page Speed tool online with an API and then created the Page Speed Service to handle some of the tricky bits of web optimization for you. Now the Page Speed service has another trick for users.
Page Speed’s new rewriter, which Google refers to as “Cache and Prioritize Visible Content,” works by optimizing three main things on your site — all of which are standard best practices for speeding up a website, but are often hard for smaller sites to pull off. First off the Page Speed rewriter isolates those parts of the page that can’t be cached (logged in user info for example) and caches the rest of the page.
The next step is, as the name implies, to “prioritize visible content rendering.” The Google blog is a little unclear on how this works, saying only that the rewriter “automatically determines and prioritizes the content that is above the fold of the browser, so that it doesn’t have to compete with the rest of the page.”
The third part of Page Speed’s optimization is to defer the loading of any JavaScript until the visible content is loaded.
At the moment the Page Speed Service is invite-only, but if you’d like to request access, head on over to the sign up page and drop your e-mail and URL in the form.
While you’re waiting for access, if you want to see what Page Speed’s rewriter might be able to do for your site, you can head over to Web Page Test, which now has a profile for the Page Speed rewriter. I ran my personal site (a very simple, static HTML site served by Nginx) through it and found that, as you can see in the image above, the rewriter considerably improved the first load time of images (pretty much the only thing that takes any time to load on my site).
