How to change the image size in html

In web design, pictures are a very important element, which can increase the beauty of the website and attract the user's attention. In many cases, we need to modify the size of the image to achieve the best effect. This article mainly introduces how to use HTML to modify the image size.

In HTML, there are two common ways to modify the image size: using the width and height attributes of the img tag and using CSS styles. Let’s introduce them one by one.

Use the width and height attributes of the img tag

The img tag is a tag used to insert pictures in HTML. The most basic usage is as follows:

<img src="image.jpg" alt="图片" />

Among them, the src attribute is used To specify the path of the image, the alt attribute is used to add a description to the image. Now we need to modify the size of the image, which can be achieved through the width and height attributes. These two attributes can specify the width and height of the image, and the unit can be pixels (px), percentage (%), or em (a multiple of the font size relative to the parent element).

Here is an example:

<img src="image.jpg" alt="图片" width="200px" height="150px" />

This code sets the width of the image to 200 pixels and the height to 150 pixels. It should be noted that if only one of the properties is set, the other property will be automatically adjusted according to the proportion of the original image to ensure that the image will not be stretched or compressed.

Using CSS styles

In addition to using the width and height attributes of the img tag, we can also use CSS styles to modify the image size. The advantage of this is that the size of all images can be controlled uniformly in one style sheet, reducing repeated code.

To use CSS to modify the image size, we need to define a class for the img tag and then set the corresponding style in CSS. The following is an example:

<img src="image.jpg" alt="图片" class="picture" />

.picture {
  width: 200px;
  height: 150px;
}

This code achieves the effect of modifying the image size by adding the class attribute to the img tag and defining the .picture class in CSS. It should be noted that in order to ensure that CSS styles take effect, the style sheet needs to be linked to the web page.

At the same time, we can also use percentages to set the size of the image, for example:

.picture {
  width: 50%;
  height: 50%;
}

This code sets the size of the image to half of the original size, which can easily implement responsive design , adapting to devices of different screen sizes.

Summary

In web design, changing the size of images is a common requirement. We can easily achieve this functionality by using the width and height attributes of the img tag or CSS styles. It should be noted that in order to ensure the performance of the web page, it is best to use appropriate image sizes to avoid loading overly large images that will affect the user experience.

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