The other day I encountered some issues with images for external sources not loading.
I saved a link to someone's Twitter profile image in this case. When the user changes this image, it doesn't auto reflect the new one.
So I decided to look into fallback images.
And it's surprisingly easy.
What we want to achieve:
- Load the image
- If it doesn't load, show the fallback
Note: Alternatively, you could decide to remove the image
Let's set up a sample HTML experiment.
<img src="https://images.pexels.com/photos/163822/color-umbrella-red-yellow-163822.jpeg" />
This will load an Photo by Pixabay from Pexels (a stock image site).
This will work perfectly, but now let's try and destroy it by randomly adding some numbers to the image.
<img src="https://images.pexels.com/photos/163822/color-umbrella-red-yellow-00000.jpeg" />
With this, we get the super annoying broken image.
So what can we do when this happens?
We can use the
onerror attribute on the image to set a fallback.
It works like this:
<img src="https://images.pexels.com/photos/163822/color-umbrella-red-yellow-00000.jpeg" onerror="this.onerror=null; this.src='https://images.pexels.com/photos/159868/lost-cat-tree-sign-fun-159868.jpeg'" />
We use the
onerror to set the error to null and set the src of the image to a fallback.
In our case, a photo of a missing cat.
Note: It's not a great practice to rely on external images. You ideally want to have the fallback image locally in the file system, so it's a reliable fallback.
You can see it in action in the following CodePen.
The first image loads, and the second one is broken.