FolioVision

There’s one problem with Gravatars. They are very slow to load. Each page with comments on them makes one call per comment to the Gravatar server. While a single call takes only a 100ms, on a page with hundreds of comments, we are talking about major slowdowns. Page loads can take 20 seconds and more.
This plugin solves this problem by:
<ul>
<li>
caching gravatars with WordPress cron job..
</li>
<li>
caching gravatars on comment submission
</li>
<li>
maintaining a single copy of the default gravatar instead of downloading it again and again for all the email addresses with no gravatar associtated
</li>
</ul>
<a href="http://foliovision.com/seo-tools/wordpress/plugins/fv-gravatar-cache/installation" rel="nofollow ugc">Installation guide</a>
<a href="http://foliovision.com/seo-tools/wordpress/plugins/fv-gravatar-cache" rel="nofollow ugc">Support and more information</a>

FV Gravatar Cache

I deactivated plugin but still contains elements in Database

Database Junk

Speeds up your website by making sure the gravatars are stored on your website and not loading from the gravatar server.

Harry Milatz

WPVerwalter

Accelerates the site speed by simply and effective caching Gravatars (Globally Recognized Avatars) so that they are delivered from the own web server and do not need to be reloaded from the Gravatar server.
NEW feature: Other Avatars, e.g. from a “social login” plugin for comments are cached in version 1.3.0 and above.
NEW feature: Avatars from captured Facebook comments with a plugin like “Facebook Comments Importer” are cached in version 1.4.0 and above. The cache have to be emptied once after update.
NEW feature: Avatars from the plugin “Wapuuvatar” are cached in version 1.4.3 and above.
NEW feature: The plugin is now ready for Multisite in version 1.5.0 and above.
NEW feature: The plugin is now ready for being used with “Avatar Manager” in version 1.5.1 and above.
NEW feature: The plugin is now ready for being used with “Jetpack’s Author Widget” in version 2.0.0 and above.
<h4>Features</h4>
You can:
<ul>
<li>change the Gravatar Size</li>
<li>add a second Gravatar Size</li>
<li>change the cachetime</li>
<li>change the option how the Gravatars will be copied to your server</li>
<li>update the options depending on the server configuration</li>
<li>build the cache in the backend and see the cached images in all cached sizes</li>
<li>empty the Cache</li>
<li>get the size to use for the Gravatars from your template or set the size manually</li>
<li>You see a statistic how many files are cached and the filesizes of the files.</li>
<li>change the output file from a JPG-Image to a PNG-Image</li>
</ul>
<h4>Translations</h4>
<ul>
<li>English (US) – <a href="https://profiles.wordpress.org/harry-milatz/" rel="nofollow ugc">Harry Milatz</a></li>
<li>English (UK) – <a href="https://profiles.wordpress.org/harry-milatz/" rel="nofollow ugc">Harry Milatz</a></li>
<li>German – <a href="https://profiles.wordpress.org/harry-milatz/" rel="nofollow ugc">Harry Milatz</a></li>
<li>German (formal) – <a href="https://profiles.wordpress.org/harry-milatz/" rel="nofollow ugc">Harry Milatz</a></li>
<li>Spanish (Spain) – <a href="https://profiles.wordpress.org/wpverwalter/" rel="nofollow ugc">WPVerwalter</a></li>
<li>German (Switzerland, Informal) – Pascal Krapf</li>
<li>German (Switzerland) – Pascal Krapf</li>
</ul>
Harrys Gravatar Cache now supports WordPress.org language packs. Want to translate Harrys Gravatar Cache? Visit <a href="https://translate.wordpress.org/projects/wp-plugins/harrys-gravatar-cache/" rel="nofollow ugc">Harrys Gravatar Cache’s WordPress.org translation project</a>.

Harrys Gravatar Cache

By default, WordPress pings gravatar for an updated image. How often do people change their image? Probably, once a month. So, one doesn't need calls to gravatar every 5 minutes. Go ahead and install this plugin. Your visitors will be happy with the speed of your site!

Thanks Harry for your time on creating and maintaining this plugin.

If you care about your users, use this plugin

Accelerates the site speed by simply and effective caching Gravatar (Globally Recognized Avatars).

FV Gravatar Cache vs Harrys Gravatar Cache