Why do some blogs have pictures next to some people’s comments?

Those are the two most common questions that I expect to get after enabling
images on posted comments here on Ask Leo!

As it turns out, many blogs use this service to add a little personality to
their comments. Personally, when I see real photos, it helps remind me that
these are real people leaving comments.

Let me explain what they are and what you might want to do if you are
interested.

Enter the Gravatar

A “Gravatar” is
a globally recognized avatar, meaning a photo or other image that you can set
up to represent you when you leave comments on blogs that make use of the
service.

A Gravatar is nothing more than an image that you provide that is associated with
your email address.

If you have multiple email addresses, you can have multiple gravatars that are either all different, all the same, or some combination of the above.

For example, here’s the Gravatar associated with my business email
address:

Privacy

What’s worth noting is that even though your email address is used to fetch
the associated image, it is not exposed. In the example above, the URL to that
image is:

http://gravatar.com/avatar/bd1d5d9661cc77d2f6e685cb4e330f5a.png

That jumble of numbers and letters is the “md5 hash” of my email address.
That’s a number that’s calculated from the text of my email address. What’s
important is that you can’t go the other way. Given an md5 hash, you cannot
reconstruct the email address that was used to generate it.

And neither can spammers.

No Gravatar? No problem

If you haven’t set up a Gravatar, sites will typically display a default
image in its place. Here at Ask Leo!, that’s this:

Different sites may use different default images or may simply assign you a
random image from a set of default images.

Setting up a Gravatar

Setting up your own Gravatar is pretty easy. Head out to Gravatar.com and begin by
entering your email address. For security’s sake, you’ll need to confirm that
you are indeed the owner of the email address by clicking on a link sent to
the email address that you specify.

Once confirmed, you can upload a photo or image that you would like to use,
associate that with your email address, and you’re done.

Setting up Gravatars on a site

As I alluded to above, using a Gravatar image is as simple as just
referencing an image where the name of the image is the md5 sum of the email
address.

The Gravatar
website has more information. Click on the link for “Developers” on the bottom
of most pages.