10 Awesome Firefox Tools Every Developer Should Know About

Firefox is known as the “developer’s browser” because it offers a wide range of tools that make our work easier. If you want to explore more tools, you can visit the Firefox Developer Tools webpage or try their Developer Edition Browser, which includes even more features and tools that are currently being tested.

In this article, I’ve compiled a list of 10 incredibly useful tools from Firefox’s developer tools collection. To make things even better, I’ve included GIFs to demonstrate what each tool can do, as well as instructions on how to access them for quick reference.

1. View and Measure with Rulers

Firefox has a handy ruler tool that allows you to display both horizontal and vertical rulers with pixel units directly on your webpage. This tool is perfect for aligning your elements perfectly across the page.

To access the rulers through the menu:

1. To access the Developer Toolbar, click on the ☰ button, then select “Developer” and “Developer Toolbar” (shortcut: Shift + F2).
2. Once the toolbar appears at the bottom of the page, type “rulers” and press Enter.
3. In order to make rulers appear on the developer tools window:
4. Go to “Toolbox Options”.
5. Under the “Available Toolbox Buttons” section, check the “Toggle rulers for the page” checkbox.
6. Another way to take screenshots is by using CSS selectors.
7. This method is particularly useful for capturing screenshots of specific elements and elements that are only visible on mouse-hover, like menus.
8. To take screenshots using this method, follow these steps:

Here’s how you can accomplish a few tasks using Firefox’s Developer Tools:

1. Take a screenshot of a specific element on a page:

1. Go to the menu ☰, then select “Developer,” and choose “Developer Toolbar” (shortcut Shift + F2).

2. Once the toolbar appears at the bottom, type “screenshot –selector any_unique_css_selector” and press enter.

To add this option to the Developer Tools window, follow these steps:

1. Click “Toolbox Options” in the toolbar.

2. Under the “Available Toolbox Buttons” section, check the “Take a fullpage screenshot” checkbox.

2. Pick colors from web pages:

Firefox has a handy color picker tool called “Eyedropper.”

To access it through the menu, go to ☰ > “Developer” > “Eyedropper.”

To see this on the developer tools window, just click “Toolbox Options” and check the “Grab a color from the page” box under “Available Toolbox Buttons.”

Now let’s move on to the next trick.

4. Take a look at the page layout in 3D.

When you view webpages in 3D, it can help you spot layout problems. You’ll be able to see the different layers of elements much more clearly in 3D view. To switch to 3D view, simply click the “3D View” button.

To make this button appear on the developer tools window, go to “Toolbox Options,” and check the “3D View” box under “Available Toolbox Buttons.”

And now, for the final trick.

5. Check out the browser style.

When you want to see the browser’s style, this trick is for you. You can see how the browser has styled different elements on the page. To do this, click the “Browser Style” button.

These cool tricks will make your developer tools window even more powerful. Have fun exploring!

When it comes to how websites look, there are two types of styles to consider: the default styles that browsers automatically assign to every element, and the styles that are specific to certain browsers, which are usually denoted by a browser prefix. Understanding these browser styles can help you identify any issues where your own styles are being overridden, as well as become aware of any browser-specific styles that are affecting your website.

To access the “Browser styles” in your browser, follow these steps:

1. Click on the ☰ menu and select “Developer” and then “Inspector”.
2. In the right section of the Inspector, click on the “Computed” tab.
3. Make sure to check the “Browser styles” checkbox.

If you prefer using a shortcut, you can press Ctrl + Shift + C to open the Inspector, and then access the “Browser styles” tab.

6. Disable JavaScript for current session

When creating a website, it’s important to ensure that it works properly even if JavaScript is disabled. This is crucial for achieving the best results and making the website accessible to screen readers. To check how your website functions without JavaScript, you can easily disable it for your current session. Here’s how:

1. Click on “Toolbox Options” and navigate to the “Advanced settings” section.

2. Check the “Disable JavaScript” checkbox.

Now that JavaScript is disabled, you can see how your website behaves without it. This is a good practice that helps you identify any issues and ensure a smooth user experience for all visitors.+

Hide CSS style from the page

In addition to JavaScript, it’s also important to consider accessibility when it comes to CSS styles on your website. The pages should still be readable and usable even if the styles are disabled. To see how your page looks without any styles applied, you can disable them using the developer tools.

To remove any CSS style (inline, internal, or external) applied on a webpage, just click on the eye symbol of the listed stylesheets in the “Style Editor” tab. Click it again to go back to the original view.

To access the “Style Editor” through the menu, go to ☰ > Developer > Style Editor (shortcut: Shift + F7).

Now, let’s move on to the next topic.

Preview the HTML content response to a request.

Firefox developer tools offer an option to preview the HTML content type responses. This allows you to preview any 302 redirects and check whether any sensitive information has been displayed in the response.

To access the “Preview” feature through the menu:

1. Go to ☰ > Developer > Network (shortcut: Ctrl + Shift + Q).

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Here’s a simplified and reimagined version of the provided text:

1. First, open the webpage you want or refresh the current page. Then, choose the specific request you’re interested in from the list of requests on the page.
2. Next, click on the “Preview” tab located in the right section of the page.

9. See how a webpage looks on different screen sizes

If you want to test how a webpage adjusts to different screen sizes, you can use the “Responsive Design View” tool. You can access this tool by clicking on the ☰ icon, selecting “Developer,” and then choosing “Responsive Design View.” Alternatively, you can use the shortcut Ctrl + Shift + M.

To enable the “Responsive Design Mode” tool button, click on “Toolbox Options” and check the box next to “Responsive Design Mode” under the “Available Toolbox Buttons” section.

10. Run JavaScript on webpages

To quickly run JavaScript on any webpage, just use the “Scratchpad” tool in Firefox. To access “Scratchpad” from the menu, go to ☰ > Developer > Scratchpad or use the keyboard shortcut Shift + F4.

To add the “Scratchpad” tool button to the developer tools window for easy access, click “Toolbox Options” and check the “Scratchpad” checkbox under the “Available Toolbox Buttons” section.