How to debug HTML code in Google Chrome Developer Tools?
Jul 11, 2025 am 01:46 AMThe key to debugging HTML code is to master several core functions of Chrome DevTools. 1. Check the element structure: quickly locate the HTML position by right-clicking "Check", expand the node to view the nested structure, and double-click modifying content for temporary testing; 2. View and modify styles: View the applied CSS rules on the right side of the Elements panel, disable a certain style to observe the impact, or add a new style to test the effect; 3. Use the console to operate the DOM and execute JS, such as obtaining elements, modifying content, and testing whether the button event takes effect; 4. Responsive design debugging: Use the device toolbar to simulate different screen sizes, and comprehensively analyze layout problems with the box model display and the Computed style panel.
Debugging HTML code is not actually mysterious, especially with the help of Chrome Developer Tools (DevTools). It allows you to view page structure, modify styles, check element status, and even simulate the performance of different devices in real time. The key is to master several common functions and operation logic.

Check element structure
The easiest way to open DevTools is to right-click any element on the web page and select "Inspect". This allows direct location of the element in HTML.

In the Elements panel, the HTML structure is on the left and the CSS style of the element is displayed on the right. you can:
- Expand or collapse nodes to view nested structures
- Click the small arrow next to the label name to quickly jump to the corresponding style
- Double-click the HTML content directly to make temporary modifications (note: these changes are only temporary, and the page will be gone if you refresh it)
If you have problems with layout, such as an element not showing as expected, use this panel to quickly confirm whether it is rendered correctly.

View and modify styles
After an element is selected in the Elements panel, all CSS rules applied to this element are listed on the right. Here are a few practical tips:
- View inherited styles : Scroll to the bottom and you can see the styles inherited from the parent, which helps you understand why an element has a specific manifestation.
- Temporarily disable a rule : Click the small check box before the attribute to temporarily close this style and observe the impact on the page.
- Add a new style : Click the number next to "style..." to add a new CSS class to the current element or directly write an inline style to test the effect.
If you find that a style is not effective, it is likely that it is because the priority is insufficient or it is overwritten by other rules.
Quick operation with the console
In addition to the Elements panel, Console (Console) is also a powerful debugging assistance tool. you can:
- Enter
document.querySelector("your-selector")
to get an element and view its properties - Modify the DOM content, for example:
element.innerHTML = "new content"
- Execute some simple JavaScript to test behavioral logic
For example, if you want to see if a button is correctly bound to the click event, you can enter it in the console:
document.querySelector('button').click()
If the page responds, the binding is successful.
Responsive design and layout debugging
Chrome DevTools also has a built-in device toolbar (shortcut keys Ctrl Shift M or Cmd Shift M) that can simulate various screen sizes. This is very useful for debugging responsive layouts.
You can also enable the "Show Element Box Model" function. When hovering elements, specific values ??of padding, border, and margin will be displayed below the panel to help you understand the box structure more intuitively.
Additionally, use the Computed tab to view all styles that end up applying on the element, including browser defaults and inherited styles.
Basically these commonly used operations. Mastering these parts, you won’t have too much headaches when debugging HTML and CSS.
The above is the detailed content of How to debug HTML code in Google Chrome Developer Tools?. For more information, please follow other related articles on the PHP Chinese website!

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