{"id":3595,"date":"2025-10-05T00:00:00","date_gmt":"2025-10-04T22:00:00","guid":{"rendered":"https:\/\/tecnologia.euroinnova.com\/z-index\/"},"modified":"2026-08-05T11:11:08","modified_gmt":"2026-08-05T09:11:08","slug":"z-index","status":"publish","type":"post","link":"https:\/\/tecnologia.euroinnova.com\/en\/z-index","title":{"rendered":"Z-Index"},"content":{"rendered":"

Z-Index<\/strong> It is a fundamental property in web development and graphical interface design. It is used in CSS (Cascading Style Sheets)<\/strong> to control the overlapping of elements on a web page, that is, which elements should appear in front of or behind others when they overlap on the screen. <\/p>\n

In web design, not all elements are on a single layer. There are situations where certain blocks, menus, images or text boxes overlap, and this is where the Z-Index<\/strong> plays a key role in determining the \u00abstacking order\u00bb of these elements. <\/p>\n

How the Z-Index works<\/strong> <\/span><\/p>\n

The property z-index<\/strong> It works by assigning an integer value to elements with \u2018relative\u2019, \u2018absolute\u2019, \u2018fixed\u2019 or \u2018sticky\u2019 positioning. The more the greater the value<\/strong>, further up<\/strong> the element will appear in the browser\u2019s rendering stack. <\/p>\n

For example, an element with `z-index: 10;` will be displayed on top of another with `z-index: 5;`, regardless of its position in the HTML code. <\/p>\n

It is important to bear in mind that the Z-Index only works on elements with a defined position<\/strong>. If an element does not have a position set, the Z-Index will have no effect. <\/p>\n

A practical example of how to use the Z-Index<\/strong> <\/span><\/p>\n

Imagine you have a drop-down menu on a web page which, when opened, should appear on top of the rest of the page\u2019s content. However, by default, the menu appears below an image that is also at the top of the page. <\/p>\n

To resolve this and ensure that the menu is displayed on top of the image, you can use the Z-Index in CSS as follows: <\/p>\n

.top-image { 
    position: relative; 
    z-index: 5; 
} 
 
.dropdown-menu { 
    position: absolute; 
    z-index: 10; 
} 
  <\/p>\n

Important considerations regarding the Z-Index<\/strong> <\/span><\/p>\n