A fast website is preferred by search engines like Google . If your blog or Website loads quickly , then Google may send more visitors . To make your website fast , you have to analyze it to find out the issues which are effecting its load time . There are lots on online and offline tools for webpage testing , here I am discussing some free online page testing tools .
With Web Page Test you can run a free website speed test from multiple locations around the globe using multiple browsers like Chrome , Firefox , IE etc . at real consumer connection speeds. You can run simple tests or perform advanced testing including multi-step transactions, video capture, content blocking and much more. Test results will provide rich diagnostic information including resource loading waterfall charts, Page Speed optimization checks and suggestions for improvements.
The page analyzer analyzes your web page performance by emulating how a web browser would load your page and all resources referenced in it. The page and the referenced resources are loaded and important performance metrics are measured and displayed in a waterfall diagram along with other per-resource attributes such as URL, size, compression ratio and HTTP status code.
Pingdom Full Page Test tool help you analyze the load speed of your websites and learn how to make them faster. It lets you identify what about a web page is fast, slow, too big, what best practices you’re not following, and so on. It examines all parts of a web page like file sizes, load times, and other details about every single element of a web page (HTML, JavaScript and CSS files, images, etc.). You can sort and filter this list in different ways to identify performance bottlenecks.
4. REDbot
REDbot is handy tool for cache validation it checks HTTP resources to see how they’ll behave, pointing out common problems and suggesting improvements. It checks your URL for a large number of common HTTP problems, including , Invalid syntax in headers, Ill-formed messages (e.g., bad chunking, incorrect content-length) ,Incorrect gzip encoding ,Missing headers and many more .
5. HTTP Archive
HTTP Archive keeps historical performance snapshots of many sites online.It provides web performance information such as size of pages, failed requests, and technologies utilized.

Thanks for the update.