Chromebleed, a new extension for Google’s browser, automatically checks websites for instances of Heartbleed and issues a warning if the site is compromised.

The application, developed by Jamie Hoyle, makes use of a tool from Filippo Valsorda and is currently only available for Google Chrome.

Writing on Lifehacker, Mihir Patkar said: "I’ve been using Chromebleed for about 4 days now and it’s stopped me on at least a dozen sites so far. Again, Heartbleed is the kind of bug you want to err on the side of caution and that’s what this lets you do."

He dismissed complaints about the effectiveness of the app, citing a series of false positives in early versions of Valsorda’s tool, but as the app provides no testing mechanism it is difficult to ascertain whether it is functioning properly.

Many of the major websites compromised by the bug have already patched their systems, including Facebook, Tumblr and Yahoo, but it is likely many remain dangerous.