02. Images

To place an image on a page, use the <img> tag. The <img> tag has no closing tag.

Important Attributes of the img tag

Used to locate the source of the image.
Set the width and height of the image.
Note that specifying the width and height together may distort the photo.
If you'd like for the photo to scale, just use one of the two.
Used to show an alternative desciption.
In case we want to display additional information for users who cannot see the image.

We can specify the image from a source on another server using an absolute link, or from our own using a relative link.

<img src="http://www.w3.org/html/logo/downloads/HTML5_Logo_512.png" alt="HTML 5 Logo" width="200px">
HTML5 logo

Or relative:

<img src="/code/img/main-logo.svg" alt="Code Snippets Academy logo">
Code Snippets Academy logo

Sample image formats

There are several image formats, each with their advantages and disadvantages. It's important to understand the filesize and its quality, as a super-high resolution may take a lot longer to load on the page. If your users are impatient, they may navigate elsewhere!


JPEG is a lossy compression format that compresses the original image. The upside to JPEGs are a smaller file size, but the drawback is that the image becomes not as clear.


GIFs contain no more than 256 colors, thus lowering the file size. We can have some pixels in the GIF to be transparent.


With a PNG, we can have 16 million colors, as well as alpha transparency. Very high resolution, so high file size.

The holy grail of them all: SVG

Scalable Vector Graphics (SVG) is an XML-based vector image format for 2d graphics. The great thing about these is no matter how large or small it gets, the image does not blur or lose quality.

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