The History of Favicons: From IE5 to Modern PWAs
Favicons started as a hack in Internet Explorer 5 and evolved into a cross-platform identity system. Here is the full timeline.
The favicon started as a tracking mechanism, evolved into a branding tool, and ended up as a cross-platform identity system spanning browser tabs, mobile home screens, search results, and progressive web apps. Going from a single 16-pixel ICO file in 1999 to the SVG-powered, dark-mode-aware icons of 2026 involved more weird detours than you'd expect.
Adoption Over Time
Favicon usage grew slowly at first, then became effectively universal as mobile web use exploded and search engines started displaying them.
The Full Timeline
Internet Explorer 5 introduces favicons
Microsoft added support for a file called favicon.ico placed at the root of a website. The format was ICO, the size was 16x16, and the purpose was to distinguish bookmarks in the Favorites menu. The sneaky part: requesting this file also let site owners detect when users bookmarked their page, making it an early (and accidental) analytics tool.
W3C standardizes the link tag
The HTML 4.01 specification added the <link rel="icon"> tag, allowing websites to specify a custom path and format for their favicon. This meant the file no longer had to be named favicon.ico or sit at the site root.
Firefox adds tab favicons
Mozilla Firefox popularized tabbed browsing, and each tab displayed the site's favicon. This was the moment favicons shifted from bookmark decoration to persistent brand visibility. Users could see your icon every time they glanced at their tabs.
Apple introduces touch icons with the iPhone
The original iPhone let users add websites to their home screen, but it needed a larger icon than 16 pixels. Apple created apple-touch-icon, a 57x57 PNG (later 180x180). This was the first time favicons needed to exist at multiple sizes for different devices.
Android adds home screen shortcuts
Android browsers started supporting home screen shortcuts with their own icon requirements. The web manifest format emerged as a way to declare multiple icon sizes in a single JSON file, laying the groundwork for PWAs a few years later.
Windows 8 tiles demand a new format
Microsoft's tile-based Start menu needed icons at completely new sizes (70x70, 150x150, 310x150, 310x310). The browserconfig.xml file was invented to declare these. Favicon sets grew from one file to a dozen.
PWA icons and maskable format
Progressive Web Apps needed installable-quality icons at 192px and 512px, plus maskable versions that could handle different shaped masks across Android device manufacturers. The "purpose: maskable" attribute was added to the web manifest.
Google adds favicons to search results
Google started showing favicons next to URLs in mobile search results. Overnight, favicons went from cosmetic to commercial: they now affected click-through rates in organic search. Sites without favicons looked unfinished next to competitors.
SVG favicons gain broad support
Chrome and Firefox added support for SVG favicons. A single SVG file could replace multiple PNG sizes, scale to any resolution, and even adjust colors automatically for dark browser themes.
The modern favicon is a system, not a file
Today a complete favicon setup includes ICO, SVG, multiple PNGs, a web manifest, browserconfig, social preview images, and maskable icons. AI-powered generators can now produce the entire package from a single text prompt, so you no longer have to deal with the manual work that piled up over 27 years.
A 27-year accretion
What Changed in 2026
The biggest shift is that SVG has become the recommended primary format. With Safari finally supporting SVG favicons on macOS, every major desktop browser can now use a single SVG file with dark mode support. The ICO fallback is kept for edge cases (PDF viewers, old email clients), but it is no longer the primary format.
AI-powered generation is the other big change. Instead of manually creating and resizing icons across 18 files, you type a prompt and get the whole package. Twenty-seven years of accumulated complexity, collapsed back into one step.