“test everything!” is a website helps you to check different things about website. It can check the HTML/CSS validation, SEO, Spell checking, Social network of your website.
Just input your website url into the box and select the tools. It will generate links to websites that offer the services.
You don’t need to visit ten or more different place to test your websites. Just go to http://tester.jonasjohn.de/ and you have all the tools there.