Modern browsers accept SVG directly as a favicon (<link rel="icon" href="favicon.svg">), but legacy contexts still expect ICO: Windows Explorer, older mobile bookmarks, some search engine crawlers, and desktop app installers. The Rankato SVG-to-ICO converter rasterizes your SVG at six standard sizes and packs them into a single Windows ICO container — the browser or OS picks the size closest to its target and displays that. This gives you a crisp icon at every size instead of a single scaled bitmap.
Why multiple sizes matter
An ICO file is a container that can hold multiple images at different resolutions. Browsers and operating systems pick the size that matches their target — 16×16 for a browser tab, 32×32 for a taskbar, 256×256 for Windows Explorer's icon view. If your ICO only contains one size, the OS scales it, which looks blurry. A well-made ICO includes all six standard sizes so every context gets a pixel-perfect render.
How rasterization works
The converter renders your SVG six times — once per size — using each size's native pixel grid. That means the 16×16 rendering is optimized for 16-pixel display (rounded to whole pixels, hairlines snapped to integer coordinates) rather than being a downscale of a larger raster. This produces the sharpest possible icon at every size.
Size selection and format
The default output includes 16, 32, 48, 64, 128, and 256 pixels. You can add 24 and 96 for specific enterprise contexts (Windows 8+ live tiles), or drop unused sizes to shave file size (an ICO with just 16/32/48 is under 5 KB; the full six-size set is ~30 KB). All sizes use 32-bit RGBA — full transparency support.
Beyond favicon: Windows apps and installers
ICO isn't just for browsers. Windows desktop apps use ICO for their .exe icon, their taskbar entry, and their Start menu tile. If you're shipping an Electron, .NET, or Rust desktop app, the ICO you generate here is what goes into your build config. NSIS, Inno Setup, and WiX all accept these files directly.
Related favicon assets
For a complete favicon set in 2026, you want more than just ICO: a modern .svg favicon for browsers that support it, PNG variants at 192/512 for Android's home-screen icon, a maskable PNG for PWA manifests, and Apple Touch Icons at 180×180. The Favicon Generator tool (in the editing suite) produces the full pack in one pass; this tool is for the ICO container specifically.