Web development tools allow web developers to test and debug their code. They are different from website builders and IDEs in that they do not assist in the direct creation of a webpage, rather they are tools used for testing the user facing interface of a website or web application.
Web development tools come as browser add-ons or built in features in web browsers. The most popular web browsers today like, Google Chrome, Firefox, Opera, Internet Explorer, and Safari have built in tools to help web developers, and many additional add-ons can be found in their respective plugin download centers.
Web development tools allow developers to work with a variety of web technologies, including HTML, CSS, the DOM, JavaScript, and other components that are handled by the web browser. Due to the increasing demand from web browsers to do more popular web browsers have included more features geared for developers.
The web's five most popular web browsers have support for web developer tools that allows web designers and developers to take a look at the make up of their pages. These are all tools that are built into the browser and do not require additional modules or configuration.
The built-in web developer tools in the browser are commonly accessed by hovering over an item on a webpage and selecting the "Inspect Element" or similar option from the context menu. Alternatively the F12 key tends to be another common shortcut.
HTML and DOM viewer and editor is usually commonly included in the built in web development tools. The difference between the HTML and DOM viewer, and the view source feature in web browsers is that the HTML and DOM viewer allow you to see the DOM as it was rendered in addition to allowing you to make changes to the HTML and DOM and see the change reflected in the page after the change is made.