Popup ALT Attribute is a Firefox extension designed to improve the accessibility of images on web pages. This tool enables users to view alternate texts for images, similar to the functionality found in older web browsers like Netscape Navigator 4.x. It enhances the browsing experience by displaying long descriptions in a multi-row tooltip format, akin to what is offered by Internet Explorer. This makes it easier for users to understand the context and content of images without requiring additional navigation or clicks.

The extension is subscription-based and falls under the personalization category, allowing users to tailor their browsing experience effectively. By providing valuable information at a glance, Popup ALT Attribute supports users who rely on descriptive text for images, thereby making the web more inclusive. This functionality not only enhances usability but also promotes better understanding of visual content.