Menu
If I know the height and width of an image that I'm going to display with an image tag, should I include the height and width attributes, or just put the information in CSS? Or both?
Ex.
<img src="profilepic.jpg" height="64" width="64" /> or
<img src="profilepic.jpg" height="64" width="64" style="height: 64px; width: 64px;" /> or
<img src="profilepic.jpg" style="height: 64px; width: 64px;" /> 
517
Adding the height and width attributes to your IMG SRC HTML tag allows the browser to know how much space to leave for an image. Without these values, the browser doesn't initially create a space for the image, which means elements surrounding the image are adjusted after it has loaded.
If you do not supply height and width explicitly the <img> element will be rendered at 0x0 until the browser can size it based on the file. When this happens it causes a visual reflow of the page once the image loads, and is compounded if you have multiple images on the page.
You should also always use the height and width attributes for every image you create on a page. The reason for this is that it dramatically speeds the display of your web page in the browser. src - This lets the browser know where to find the image file on the web server.
Without the width and the height the image does not know how large it is, which causes an unwanted jump in the page as it loads (it reflows). Declaring height and width solves this problem. Note that: Images with a defined width and height can still be responsive.
According to Google Page Speed, you should always define the width and height in the image tag. But, to validate you can't use the style tag.
Also, you should always specify the same height and width as the actual image so the browser doesn't have to do any modifications to it like resizing.
I'd suggest doing it
<img src="..." height="20" width="50"> Edit: Someone suggested in the comments that it would be faster to just not add any attributes. According to Google (not that they are the end all of browser knowledge):
If no dimensions are specified in the containing document, or if the dimensions specified don't match those of the actual images, the browser will require a reflow and repaint once the images are downloaded. To prevent reflows, specify the width and height of all images, either in the HTML tag, or in CSS. - Read More
Given that, you could do the img dimensions in CSS, but to validate you would have to do it in a CSS file, not inline.
BTW, Google Page Speed is a series of tips focused on rendering the page faster.
173
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
