AuntieTuna is a free browser extension developed by Calvin Ardi (cardi) for the Chrome platform. It falls under the category of Browsers and is classified as an Add-ons & Tools subcategory. The primary function of AuntieTuna is to check webpages for potential phishing attempts based on snapshots of known good sites.

The extension works by allowing users to add snapshots of trusted websites, such as Bank of FooBar. Whenever the user visits a webpage, AuntieTuna compares it to the snapshots and determines if it resembles the trusted website. If it does, it is likely to be a phishing website and is subsequently blocked.

AuntieTuna provides a quick start guide for users to easily set up the extension and start protecting themselves against phishing attacks. The extension is open source and licensed under GPLv3, ensuring transparency and accountability.