1. Google’s PageSpeed Insights
This is a very useful online tool which will give you a pretty good idea about a site’s performance. Just enter the website’s URL and it will list out the entire report as per their priority. If you are a website’s owner then this will help you a lot. It will give you all possible suggestions that you can do to increase your site’s performance. I personally liked this service a lot because it has been made by big G.
2. Yslow
This is a very useful plugin for Firefox made by Yahoo to check whether a site is slow as per Yahoo’s rule and the reason for being slow. This will give you a detail report about javascript, different components, images, CSS, DOM elements associated with the webpage. Some sample suggestions given by Yslow are:
- Avoid empty src or href
- Put CSS at top
- Put JavaScript at bottom
- Avoid URL redirects
3. GTmetrix
This is a very old website which will generate a detail report about a webpage based upon different factors like Minify JavaScript, Avoid bad requests, Optimize images, Remove unused CSS and many more. This is a bit user friendly website because for each factor it will show you a grade and also it will show you the detail reason for getting low grade in a particular factor.
4. WhichLoadsFaster
This is a very interesting place to compare two websites side by side. Just go the website, enter two URLs and press enter. It will analyze for a second and show you which one is faster and how much time faster. Following image shows a sample output of the website.
I really loved this website because of its cool result. It will only give you an idea about the speed of websites. It does not give any suggestions to increase the performance.