Comparison of OpenID providers

Comparison of OpenID providers

This Comparison is Biased a bit towards the RP's perspective

Tested providers

Grade Company / Identity URL Comment One user ⇔ one ID * Checked
★★★★ http://stackexchange.com OpenIDs are not their main service. Really simple signup process. YES 2015-Jan
★★★ http://pip.verisignlabs.com The only pretty much "pure" authentication/security company. (the other ones have something else as their main service) It has a relatively simple signup process, and works great. NO 2015-Jan
username.wordpress.com Signing up implies a lot of other stuff. If you're not already logged in when you try to use your OpenID, then you must visit the site separately and log in first. Doesn't work with Node.js's openid module YES 2015-Jan
username.livejournal.com OpenIDs are not their main service, but they have a very simple signup process. Doesn't work with Node.js's openid module. YES 2015-Jan
http://openid.yahoo.com YES 2015-Sep
https://www.flickr.com YES 2015-Sep


Untested providers:

From this list I found some other providers which I haven't tested yet:
Grade Company / Identity URL Comment One user ⇔ one ID * Checked
http://openid.aol.com/username YES
https://www.blogspot.com/ YES
(Paypal:) https://www.x.com/developers/paypal/documentation-tools/quick-start-guides/standard-openid-integration-paypal-access YES

*Does the IdP try to maintain uniqueness.

Providers that have closed down:

See also: