Earlier this week I wrote about and published a video about making memory games with Flippity. Almost every time I write about Flippity I get an email from someone who has run into a problem with images not rendering. This week was not an exception to that pattern. 

There are generally two reasons why an image link doesn’t render an image in a Flippity template. The first reason is that the link itself is incorrect. The link (URL) has to end in .png or .jpg or .jpeg in order to work correctly. You can usually find the correct URL by simply right-clicking on the image and selecting “copy image address.” 
The other reason why an image link might not work in a Flippity template is that the image host doesn’t allow hotlinking. For example, Pixabay doesn’t allow hotlinking to its images.
What is hotlinking?
In a nutshell, hotlinking is inserting a picture into a blog post through a URL rather than uploading the image file itself to your blog. You can read more about hotlinking on the Simple English Wikipedia or on Host Gator’s page about preventing hotlinking to your own work.

Why you and your students should avoid hotlinking.
Hotlinking itself isn’t bad if you’re only linking to images that you own and control online. For example, let’s say that you have a Flickr account to which you upload dozens of pictures that you took. You could use the embed code or the link that Flickr provides to post your images in your blog post.

When hotlinking causes trouble is when you link to another person’s image hosted in their account or on their servers. Even if the image is in the public domain you probably don’t want to hotlink to it. In fact some services, like Pixabay which hosts public domain images, block attempts at hotlinking. They block hotlinking because when you hotlink you’re using more of their bandwidth than if you simply downloaded the image to your computer then uploaded it to your blog.

The biggest concern about hotlinking is not knowing exactly who or what you’re linking to. As Sue implied in her Tweet this morning, it is possible that the image you linked to and the image displayed could be changed without warning. It’s also possible that the link a student inserts to hotlink links back to site or host laden with malware that could then rain down havoc on your blog.