And now for something a little geekier.
A client of mine asked me about hotlinking images on her blog, Web etiquette, and such things; she isn’t online at the moment — I can’t blame her… It is the middle of the night, after all — so I’m taking the opportunity to throw an answer together here for anyone’s benefit.
Before we can discuss hotlinking, though, it is imperative to define it to prevent any misunderstandings. Basically, hotlinking is displaying an image on your Website while the image itself is being referenced from another Website.
An example of hotlinking can be seen in the comments of Kingdom Geek; each comment includes an avatar image. These images are hotlinked because while they may be displayed on a rickbeckman.org page, they are being referenced from gravatar.com.
This is evident from the HTML used to display the image: <img width="80" height="80" class="avatar avatar-80" src="http://www.gravatar.com/avatar/dadc4a075213f0ae6942768eb234f49e?s=80&d=identicon&r=R" alt=""/>
In a nutshell, hotlinking is displaying images on your site without first saving them to your own server.
You may have heard that hotlinking is bad etiquette, and generally, that is true.
You see, while services such as Gravatar or even Flickr are setup to allow remote linking of their images on other sites, most Websites aren’t. While linking to images on others sites may indeed work just fine, you are causing their bandwidth to be used to display items on your site.
In a real sense, this is stealing, and depending on just how much of their bandwidth you are using, you could cause them to incur overage charages with their site host.
Additionally, hotlinking may be bad for your site as it is placing a reliance upon someone else’s site. If their server goes down, your site is left with a broken image. If their webmaster decides to discourage hotlinking by dynamically replacing all remotely loaded images with a shocking or otherwise embarrassing picture, your site will display it until you replace the image, preferably with one hosted on your own server — for example, by using WordPress’ “add media” functionality while posting.
In order to avoid hotlinking and ensure that you are not committing any online faux pas, here are some things to keep in mind while you add media to your site:
- Whenever possible, link to media on your own server(s).
- If uploading media to your own server is not possible or practical, look for services that allow hotlinking to their content; these include but are not limited to Flickr and YouTube.
- If uploading media to your own server is not possible or practical and it is unclear whether the media you want to use is on a site which allows hot links, take the time to contact the site owner or webmaster to ask permission to hotlink the image.
- Do link back to the source of the media you are using, either by wrapping the image in
A tags, placing a link below the media, or including the citation in a footnote.
If you happen to be on the other side of the hotlinking fence and would like to ensure that your media isn’t being hotlinked from elsewhere, check out this tutorial, just one of the excellent resources available at Perishable Press.