ICO to WEBP Converter
Extract the largest frame from a Windows .ico icon and export it as WEBP — no upload, runs in your browser.
How the ICO to WEBP converter works
Windows .ico files are a container format that can bundle several square frames at different sizes — commonly 16×16, 32×32, 48×48, and 256×256 — either as raw uncompressed bitmaps (DIB / BITMAPINFOHEADER) or as embedded PNG images. This tool reads the ICONDIR header directly, decodes whichever frame has the largest pixel area (parsing the BMP color and transparency masks by hand when the frame isn't already PNG-encoded), and draws it onto a canvas.
From there, the canvas is re-encoded as WEBP using the browser's native canvas.toBlob WEBP encoder, which typically produces noticeably smaller files than PNG at a visually similar quality — useful for turning a legacy favicon or app icon into a modern web-optimized image. Adjust the quality slider to trade off file size against fidelity. Everything happens locally in your browser; the icon file is never uploaded anywhere.
Built and maintained by Meet Shah · Last updated
What this tool is used for
- Extracting the largest frame from an icon into a modern format.
- Converting a favicon for a tool that will not open an icon file.
- Getting a compact raster copy of an icon.
- Inspecting what an inherited favicon contains.
- Getting a modern format copy so the icon can sit alongside other WebP assets.
Frequently Asked Questions
- Why convert an icon to WebP?
- Size, mostly. WebP is typically 25–35% smaller than PNG at the same visual quality and keeps a full alpha channel, so it is a straight improvement for a favicon or an app icon served over the web — where ICO's multi-size container buys nothing.
- What happens to the other sizes in the ICO?
- They are dropped. An ICO holds several images and WebP holds one, so the conversion picks a frame — normally the largest — and discards the rest. That is a real loss if the file was serving the OS a size for each context.
- Is WebP lossless or lossy?
- Both, as separate modes. Lossless WebP (VP8L) is the right choice for an icon — flat colour and hard edges, where lossy compression produces visible ringing. Lossy WebP is for photographs, and choosing it for an icon is the mistake to avoid here.
- Can I use WebP as a favicon?
- Browsers accept it through `<link rel="icon" type="image/webp">`, but the implicit `/favicon.ico` request cannot be answered by it, and some feed readers and older tools only understand ICO or PNG. Keeping a PNG alongside is the pragmatic arrangement.
- Does transparency survive?
- Yes — WebP supports 8-bit alpha in both modes, which is more than the old BMP-based ICO frames could manage with their 1-bit mask. That is why a converted icon often has cleaner edges than the source did.
Common errors and gotchas
- Losing every frame but one, since an icon file holds several sizes.
- Choosing lossy encoding for a frame this small, where the artefacts occupy a visible share of it.
- Choosing lossy WebP for a small icon, where the artefacts are proportionally large.
- Assuming the result works as a favicon, which needs the multi-size format back.
- Losing transparency if the converter flattens the alpha channel.