Section 1.1: Getting Started with Chrome Developer Tools

If you're unfamiliar with Chrome Developer Tools, there's no need to panic. You don't have to be a coding expert to make use of them. They may seem daunting at first, but once you learn how to access them, you’ll unlock a powerful set of web-based capabilities.

To open Chrome DevTools, use the following shortcuts:

• On Windows: Press Ctrl + Shift + I
• On Mac: Press Command + Option + I

You should see the Chrome Developer Tools interface appear.

Section 1.2: Exploring the Command Menu

If you're already familiar with Chrome DevTools, you might not know that it features a command palette similar to that of VS Code. This palette contains an extensive array of commands.

After opening Developer Tools, you can access the Command Menu with:

• On Windows: Ctrl + Shift + P
• On Mac: Command + Shift + P

Simply type an angle bracket to see the complete list of commands available to you.

One particularly handy command allows you to take screenshots of an entire page, a specific area, or an individual DOM node. For a detailed guide on capturing browser-based screenshots, check out my comprehensive article [here](#).

Section 2.1: Inspecting Webpage Files

Let's dive deeper into the capabilities of Chrome DevTools. Open the command palette again without typing anything, and you’ll see a list of files that include the HTML, CSS, JavaScript, and images used on the webpage. Clicking on a file will take you to the sources tab, where you can edit and inspect the content. If the file appears minified in production, you can click the "pretty print" button (the brackets at the bottom left of the open file) to make it more readable.

Section 2.2: Analyzing Visual Coverage

In the bottom right corner of an opened file, look for the coverage option. To follow along, you can visit CNN.com. Open the command palette, find the relevant file, and click on it to access the coverage panel. This panel shows you how much of your JavaScript or CSS files are utilized in the visual elements of the page. Red bars indicate unused or unnecessary code, which could slow down your application, helping you identify what is essential for your production bundle.

Section 2.3: Executing JavaScript in the Console

Did you know you can run JavaScript code directly in your browser? While in DevTools, navigate to the Console tab. Here, you can use the dollar sign ($) as a shorthand for document.querySelector, or double dollar sign ($$) for querySelectorAll to select multiple elements. If you select an element in the Elements tab and return to the Console, typing $0 will reference the currently selected element.

To observe how an element's value changes over time, instead of repeatedly executing the same line of code, click the eye icon to pin it as a live expression. This will automatically update whenever the application state changes.

Section 2.4: Running Advanced JavaScript Snippets

For more complex JavaScript tasks, you can create snippets. Open the command palette and choose the option to create a new snippet. This will open a new file where you can write any JavaScript code you'd like, such as:

alert("I'm learning here");

To test your code, open the command palette again and type a bang (!) to find your code snippet, then execute it.

Section 2.5: Copying Elements for Web Scraping

While experimenting with JavaScript is useful, you’ll often use DevTools to debug HTML and CSS. Navigate to the Elements tab, and if you want to copy an element for inspiration, you can simply use Ctrl + C. However, right-clicking gives you a variety of copy options that can be more effective.

If you admire the styles of an element, you can copy its styles and paste them directly into your CSS. To inspect an element in different states, such as when hovered or focused, right-click on the element and choose the option to force a specific state, allowing for easier inspection of its CSS.