Firefox 156 Improves Performance for Large Images and PDFs, Introduces AI Control Features

Firefox 156, the second release since Mozilla adopted a twice-monthly release schedule, introduces several performance improvements and new features. The browser now uses libjpeg-turbo’s IDCT scaling to reduce large JPEG images during decoding, rather than loading full-size images and then shrinking them. Benchmarks show up to 20% less memory usage during very large image loading, with decoding up to twice as fast. These improvements are efficient behind the scenes without noticeable changes to the user experience. The built-in PDF viewer starts up to 45% faster as the browser now loads the background PDF.js worker sooner rather than launching it only when needed. Sponsored suggestions in the address bar are now live for users in France, Germany, and Italy, though these can be disabled via Settings > Search > Firefox Suggest > Suggestions from Sponsors. The release also includes various bug fixes. Looking ahead, Firefox 157 will add support for JPEG XL (JXL), a modern image format that offers the same quality as JPEG at a significantly smaller size. Safari is currently the only browser supporting JXL, though Chrome supported it until 2022. Additionally, Firefox emphasizes user control over AI features, offering an AI controls section within General Settings. This allows users to block current and future AI features and related pop-ups with a single toggle. Specific AI features like AI translations, image alt text in PDF viewer, tab group suggestions, and key points in link previews can be individually toggled on or off. Smart Window, Firefox’s most integrated AI experience, uses only the context shared by the user to help with tasks, connecting information across open tabs and browsing history without requiring repeated context input. The browser also notes that users can block Google’s AI Overviews using over 100 available extensions. These updates reflect Mozilla’s focus on performance, user choice, and privacy in their browser development.