These tools check webpages or websites for loading speed, search engine optimisation, security, and other useful properties. You may need to try each one to get a complete picture of website performance.
1&1 provide this simple single-page checker, which gives a basic overview of key features.
Although it requires a free registration to conduct more than one test per month, Dareboost's single-page checker provides deeper analysis than 1&1, especially with regard to web security.
In its free-to-use form, the single-page GTmetrix performance report is just an aggregator for Google's PageSpeed and the open-source YSlow. But it kills two birds with one stone and presents the results nicely enough.
The free version will only check up to five pages, but Nibbler's performance report is another good overview with emphasis on how easy your site is to find.