One of the key focuses of the Chrome Developer Summit this year is speeding up the web, and that includes offering developers tools to help their sites and web apps load quicker. Labeling sluggish sites might prompt developers to take advantage of such tools.
The idea is to flag when sites are designed in a way that tends to make them slow, taking into account historical loading times. Eventually, Google might let you know if a page might take a while to display properly because of your device or connection, too. On the other hand, it might reward fast-loading sites with positive so-called "speed badging."
Google is exploring several options for how to make it clear when sites are notably fast or slow. Among the ideas it's experimenting with are changing the color of the progress bar (i.e. green for quick-loading sites) or displaying a loading message for sites that crawl onto your screen.
It's not clear when Google will roll out speed badging or even if it'll actually do so (the Chromium blog post on the idea doesn't firmly commit to bringing the feature to Chrome). Still, it's clear Google hopes to make the web faster for everyone -- even if it might have to embarrass some developers to make it happen.