Das hier ist eine recht gute Zusammenfassung: 20 Free Online Tools for Website Speed Testing
Es lohnt sich wirklich da mal kurz drüber zu skrollen :)
We all should be aware by now that Internet users are impatient when it comes to waiting for a web page to load. Thus, your website’s performance and ability to render speedily is critical to its usability and, ultimately, its success.
In order to help you build faster websites and identify troublesome website performance bottlenecks, consider incorporating some of the following tools into your web development process.