You will need to test your web pages as you design them in the major browsers: Chrome, Firefox, Internet Explorer 11 and Microsoft Edge. All these browsers can be obtained free of charge, so it should be no hardship to get them. Unfortunately, directly testing your site is the only way you can be really sure that it works the way you want it to on your visitors' machines. In addition, if you have a smartphone, try out your site there too.
HTML & CSS : HTML (Hyper Text Markup Language) and CSS (Cascading Style Sheets) are the most basic building blocks of web coding. Using HTML you can make the basic layout of your webpage. CSS will allow you to make it more good looking. You’ll have to master coding with HTML and CSS. Further, you should know about Bootstrap. Bootstrap is a CSS framework. It provides you a jumping-off point for faster coding.
But testing gets complicated because some browsers only run on certain operating systems. Apple Safari runs on iOS and Mac OS, while Internet Explorer runs only on Windows. It's best to take advantage of services like Browsershots or Browserstack. Browsershots furnishes screenshots of your website as it will look in various browsers. Browserstack actually gives you full remote access to virtual machines so you can test your site in the most common environments. Alternatively, you can set up your own virtual machine, but that takes some expertise. (If you're going that route, Microsoft has some tools for developers including a ready-to-use virtual machine at modern.ie.) how to build a website