Convert WebP to ICO (favicon)

No — that is the whole reason I built this. The conversion runs in your browser using WebAssembly, so your files never leave your device; there is no server in the loop at all. It also means the tool keeps working offline once the page has loaded, and there is no file size limit beyond your device’s memory.

Yes, fully — the icons are written as 32-bit images with 8-bit alpha, so soft shadows and anti-aliased edges from the WebP come through intact. Your icon sits cleanly on both light and dark browser themes, with no white box around it.

Icons are square by definition, so the tool takes the largest centered square and scales that down to each size. If the crop would lose something important — a wide wordmark, for instance — crop or square the image yourself first, or use just the logo symbol rather than the full lockup.

Modern browsers do accept <link rel="icon" type="image/webp">, so you can. The .ico still earns its keep as the universal fallback: crawlers, RSS readers, pinned tabs on older systems and anything that blindly requests /favicon.ico. Shipping both covers every consumer.

Functionally no — both carry full alpha, so the favicon comes out identical either way; use whichever file you actually have. The one caution is generational: if the WebP is a heavily compressed save from a website, its artifacts get baked into all three icon sizes. A clean export from your design tool beats a rescued web asset.

If the WebP is not square-ish and not a mark — converting a banner or product photo produces a cropped blob in the tab. And if you are building a new site anyway, consider authoring the icon as vector first: SVG to ICO renders each size from geometry and stays sharper at 16px than any raster source can.