This is limited to three "link safety" extensions available in the "Chrome Store". All are free.

Web of Trust, McAfee and Norton Safe Web.

1. Web of Trust:

Based on user experience and reporting by (site claim) millions of users. States they are “trustworthy”, although how they conclude this is unclear.

Like:  Unobtrusive, geared to color blind people as well, Shows trust ratings when using Google, Bing, Yahoo.

Don’t like:  Does not work on Scroogle searches. Requires a “user account”, so you’ll probably get spammed (use a ‘throwaway’ email).  Also, thousands of websites are created daily, so many are an “unknown” quantity for WoT, much like “signature” antivirals vs, heuristic or “behavioral” ones. Unless a site has been reported, you’re in the dark.

2. McAfee’s “Site Advisor”:

This may be SiteAdvisor, but it's not strictly McAfee's SiteAdvisor.  Read what it says : "Based on SiteAdvisor", and then search or Google for "chrome.dev.ext" and you find that this extension was supplied back in 2008 by Brothersoft.

Then, search or Google for Brothersoft, and check them on WOT. Then decide if you still want the extension. To me, it’s a McAfee-Brothersoft hybrid product, bought from Brothersoft and unclear how much of the present product is actually the original “Site Advisor”.

3. Norton Safe Web:

Not strictly a Chrome extension, it’s a “Look it up through us” tool bar appearing thing described as a “Service” in which you enter a url and the site is then rated. Might be ok, but I dislike toolbars and there’s obviously a commercial info angle to this “service”.

Norton describes it:

“Norton Safe Web Lite uses signature-based file scanning, intrusion detection engines, behavioral detection and install and uninstall analysis to identify potentially dangerous Web sites. It's the most sophisticated FREE protection you can get.”

I doubt it. I don't like the possibility - wait, probability that info is being collected and sold.

So, someone’s going to ask, “How about ‘Comodo Dragon’ Chrome” ?

Good:  Only slightly slower than the original ‘Chrome’. Chrome simple interface.

Bad:  Based on an older version of Chrome. Won’t allow Chrome extensions. To me, that’s a deal breaker, unless you use the latest version 12.2 which does work with extensions.

Another very good article to read about "Chrome Security Extensions" is:

http://www.techrepublic.com/blog/10things/10-chrome-extensions-that-enhance-online-security/1548

Although it's not strictly related to "link safety". There are good extensions listed there, but remember, the hackers exploit extension code weaknesses.

Good: AVG’s free Link Scanner works with Comodo Chrome.

Source: http://www.thewindowsclub.com/3-chrome-extensions-safe-browsing