The Chromium blog notes that the identification may take several forms and that it plans to experiment with different options to determine which gives the most value to users. Badging will identify sites that are designed in a way that makes them generally slow by looking at historical load latencies. Down the road, Chrome may expand the notification to include identifying when a page is loading slowly for a user based on their device or network conditions.
To start, several Chrome surfaces are being looked at, including the loading screen, loading progress bar, and context-menu for links. The latter feature might identify typical site speeds before users navigate to the website. The identification of fast and slow websites will happen in gradual steps and will be based on increasingly tough criteria. The long-term goal for Chromium is to define badging for high-quality experiences.
The definition of a high-quality experience could include more than speed, according to Google. Speed badges are being built in collaboration with other teams at Google that are exploring labeling the quality of experiences at Google. Chromium notes that it doesn't want sites to be inconsistently badged from one surface to another.
The team says that it is being "very mindful" of the approach to setting the bar for what is considered a good user experience, and hopes to land on something that is practically achievable by all developers. Updates will be offered in the future, but Google urges developers to not wait for site optimization. It's unclear if the new feature will only come to Chrome or if it will come to all Chromium browsers, including Chromium Microsoft Edge launching in January.