CSS Reference

By Kayce Basques

Technical Writer, Chrome DevTools & Lighthouse

Discover new workflows in this comprehensive reference of Chrome DevTools features related to viewing and changing CSS.

See Get Started with Viewing and Changing CSS to learn the basics.

Select an element

The Elements panel of DevTools lets you view or change the CSS of one element at a time. The selected element is highlighted blue in the DOM Tree. The element's styles are shown in the Styles pane. See View an element's CSS for a tutorial.

Figure 1. The h1 element that's highlighted blue in the DOM Tree is the selected element. To the right, the element's styles are shown in the Styles pane. To the left, the element is highlighted in the viewport, but only because the mouse is currently hovering over it in the DOM Tree

There are many ways to select an element:

• In your viewport, right-click the element and select Inspect.
• In DevTools, click Select an element or press Command+Shift+C (Mac) or Control+Shift+C (Windows, Linux), and then click the element in the viewport.
• In DevTools, click the element in the DOM Tree.
• In DevTools, run a query like document.querySelector('p') in the Console, right-click the result, and then select Reveal in Elements panel.

View CSS

View the external stylesheet where a rule is defined

In the Styles pane, click the link next to a CSS rule to open the external stylesheet that defines the rule.

If the stylesheet is minified, see Make a minified file readable.

Figure 2. Clicking devsite-google-blue.css:487 takes you to line 487 of devsite-google-blue.css, where the .devsite-article h1:first-of-type CSS rule is defined.

View only the CSS that's actually applied to an element

The Styles tab shows you all of the rules that apply to an element, including declarations that have been overridden. When you're not interested in overridden declarations, use the Computed tab to view only the CSS that's actually being applied to an element.

1. Select an element.
2. Go to the Computed tab in the Elements panel.

Note: On a wide DevTools window, the Computed tab does not exist. The contents of the Computed tab are shown on the Styles tab.

Inherited properties are opaque. Check the Show All checkbox to see all inherited values.

Figure 3. The Computed tab shows the CSS properties being applied to the currently-selected h1 element

View CSS properties in alphabetical order

Use the Computed tab. See View only the CSS that's actually applied to an element.

View inherited CSS properties

Check the Show All checkbox in the Computed tab. See View only the CSS that's actually applied to an element.

View an element's box model

To view the box model of an element, go to the Styles tab. If your DevTools window is narrow, the Box Model diagram is at the bottom of the tab.

To change a value, double-click on it.

Figure 4. The Box Model diagram in the Styles tab shows the box model for the currently selected h1 element

Search and filter an element's CSS

Use the Filter text box on the Styles and Computed tabs to search for specific CSS properties or values.

To also search inherited properties in the Computed tab, check the Show All checkbox.

Figure 5. Filtering the Styles tab to only show rules that include the search query color

Figure 6. Filtering the Computed tab to only show declarations that include the search query 100%

Toggle a pseudo-class

To toggle a pseudo-class like :active, :focus, :hover, or :visited:

1. Select an element.
2. On the Elements panel, go to the Styles tab.
3. Click :hov.
4. Check the pseudo-class that you want to enable.

Figure 7. Toggling the :hover pseudo-class. In the viewport you can see that the background-color: cornflowerblue declaration is being applied to the element, even though the element is not actually being hovered over

See Add a pseudostate to a class for an interactive tutorial.

View a page in print mode

To view a page in print mode:

1. Open the Command Menu.
2. Start typing Rendering and select Show Rendering.
3. For the Emulate CSS Media dropdown, select print.

View used and unused CSS with the Coverage tab

The Coverage tab shows you what CSS a page actually uses.

1. Press Command+Shift+P (Mac) or Control+Shift+P (Windows, Linux, Chrome OS) while DevTools is in focus to open the Command Menu.

2. Start typing coverage and select Show Coverage. The Coverage tab appears.

   

   Figure 8. Opening the Coverage tab from the Command Menu

   

   Figure 9. The Coverage tab

3. Click Start Instrumenting Coverage And Reload Page . The page reloads and the Coverage tab provides an overview of how much CSS (and JavaScript) is used from each file that the browser loads. Green represents used CSS. Red represents unused CSS.

   

   Figure 10. An overview of how much CSS (and JavaScript) is used and unused

4. Click a CSS file to see a line-by-line breakdown of what CSS it uses.

   

   Figure 11. Lines 55 to 57 and 65 to 67 of devsite-google-blue.css are unused, whereas lines 59 to 63 are used

Force print preview mode

See Force DevTools Into Print Preview Mode.

Change CSS

Add a CSS declaration to an element

Since the order of declarations affects how an element is styled, you can add declarations in different ways:

• Add a inline declaration. Equivalent to adding a style attribute to the element's HTML.
• Add a declaration to a style rule.

What workflow should you use? For most scenarios, you probably want to use the inline declaration workflow. Inline declarations have higher specificity than external ones, so the inline workflow ensures that the changes take effect in the element as you'd expect. See Selector Types for more on specificity.

If you're debugging an element's styles and you need to specifically test what happens when a declaration is defined in different places, use the other workflow.

Add an inline declaration

To add an inline declaration:

1. Select an element.
2. In the Styles pane, click between the brackets of the element.style section. The cursor focuses, allowing you to enter text.
3. Enter a property name and press Enter.
4. Enter a valid value for that property and press Enter. In the DOM Tree, you can see that a style attribute has been added to the element.

Figure 12. The margin-top and background-color properties have been applied to the selected element. In the DOM Tree you can see the declarations reflected in the element's style attribute

Add a declaration to a style rule

To add a declaration to an existing style rule:

1. Select an element.
2. In the Styles pane, click between the brackets of the style rule to which you want to add the declaration. The cursor focuses, allowing you to enter text.
3. Enter a property name and press Enter.
4. Enter a valid value for that property and press Enter.

Figure 13. Adding the border-bottom-style:groove declaration to a style rule

Change a declaration name or value

Double-click a declaration's name or value to change it. See Change declaration values with keyboard shortcuts for shortcuts for quickly incrementing or decrementing a value by 0.1, 1, 10, or 100 units.

Figure 14. Changing the value of the border-bottom-style declaration

Change declaration values with keyboard shortcuts

While editing the value of a declaration, you can use the following keyboard shortcuts to increment the value by a fixed amount:

• Option+Up (Mac) or Alt+Up (Windows, Linux) to increment by 0.1.
• Up to change the value by 1, or by 0.1 if the current value is between -1 and 1.
• Shift+Up to increment by 10.
• Shift+Command+Up (Mac) or Shift+Page Up (Windows, Linux) to increment the value by 100.

Decrementing also works. Just replace each instance of Up mentioned above with Down.

Add a class to an element

To add a class to an element:

1. Select the element in the DOM Tree.
2. Click .cls.
3. Enter the name of the class in the Add New Class text box.
4. Press Enter.

Figure 14. The Element Classes pane

Toggle a class

To enable or disable a class on an element:

1. Select the element in the DOM Tree.
2. Open the Element Classes pane. See Add a class to an element. Below the Add New Class text box are all of the classes that are being applied to this element.
3. Toggle the checkbox next to the class that you want to enable or disable.

Add a style rule

To add a new style rule:

1. Select an element.
2. Click New Style Rule . DevTools inserts a new rule beneath the element.style rule.

Figure 15. DevTools adds the h1.devsite-page-title style rule after clicking New Style Rule

Choose which stylesheet to add a rule to

When adding a new style rule, click and hold New Style Rule to choose which stylesheet to add the style rule to.

Figure 16. Choosing a stylesheet

Add a style rule to a specific location

To add a style rule to a specific location in the Styles tab:

1. Hover over the style rule that is directly above where you want to add your new style rule.
2. Reveal the More Actions toolbar.
3. Click Insert Style Rule Below .

Figure 17. Insert Style Rule Below

Reveal the More Actions toolbar

The More Actions toolbar lets you:

• Insert a style rule directly below the one you're focused on.
• Add a background-color, color, box-shadow, or text-shadow declaration to the style rule you're focused on.

To reveal the More Actions toolbar:

1. In the Styles tab, hover over a style rule. More Actions is revealed in the bottom-right of the style rule's section.

   

   Figure 18. After hovering over the .devsite-article h1:first-of-type style rule, More Actions is revealed in the bottom-right of the style rule's section

2. Hover over More Actions to reveal the actions mentioned above.

   

   Figure 19. The Insert Style Rule Below action is revealed after hovering over More Actions

Toggle a declaration

To toggle a single declaration on or off:

1. Select an element.
2. In the Styles pane, hover over the rule that defines the declaration. Checkboxes appear next to each declaration.
3. Check or uncheck the checkbox next to the declaration. When you uncheck a declaration, DevTools crosses it out to indicate that it's no longer active.

Figure 20. The color property for the currently-selected element has been toggled off

Add a background-color declaration

To add a background-color declaration to an element:

1. Hover over the style rule that you want to add the background-color declaration to.
2. Reveal the More Actions toolbar.
3. Click Add Background Color .

Figure 21. Add Background Color

Add a color declaration

To add a color declaration to an element:

1. Hover over the style rule that you want to add the color declaration to.
2. Reveal the More Actions toolbar.
3. Click Add Color .

Figure 22. Add Color

Add a box-shadow declaration

To add a box-shadow declaration to an element:

1. Hover over the style rule that you want to add the box-shadow declaration to.
2. Reveal the More Actions toolbar.
3. Click Add Box Shadow .

Figure 22. Add Box Shadow

Add a text-shadow declaration

To add a text-shadow declaration to an element:

1. Hover over the style rule that you want to add the text-shadow declaration to.
2. Reveal the More Actions toolbar.
3. Click Add Text Shadow .

Figure 23. Add Text Shadow

Change colors with the Color Picker

The Color Picker provides a GUI for changing color and background-color declarations.

To open the Color Picker:

1. Select an element.

2. In the Styles tab, find the color or background-color declaration that you want to change. To the left of the color or background-color value, there is a small square which is a preview of the color.

   

   Figure 24. The small blue square to the left of rgb(123, 170, 247) is a preview of that color

3. Click the preview to open the Color Picker.

   

   Figure 25. The Color Picker

Here's a description of each of the UI elements of the Color Picker:

Figure 26. The Color Picker, annotated

1. Shades.
2. Eyedropper. See Sample a color off the page with the Eyedropper.
3. Copy To Clipboard. Copy the Display Value to your clipboard.
4. Display Value. The RGBA, HSLA, or Hex representation of the color.
5. Color Palette. Click one of these squares to change the color to that square.
6. Hue.
7. Opacity.
8. Display Value Switcher. Toggle between the RGBA, HSLA, and Hex representations of the current color.
9. Color Palette Switcher. Toggle between the Material Design palette, a custom palette, or a page colors palette. DevTools generates the page color palette based on the colors that it finds in your stylesheets.

Sample a color off the page with the Eyedropper

When you open the Color Picker, the Eyedropper is on by default. To change the selected color to some other color on the page:

1. Hover over the target color in the viewport.

2. Click to confirm.

   

   Figure 27. The Color Picker shows a current color value of #212121, which is close to black. This color would change to the blue that's currently highlighted in the viewport once the blue was clicked

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