Convert ICO icons to WebP
Extract icons from ICO files and convert to modern WebP. The largest variant from each ICO becomes the WebP output, with transparency preserved.
ICO-to-WebP converter in development
ICO parsing needs custom container handling (the format supports both raw BMP and embedded PNG variants). The rest of the page describes how the conversion will work and what to expect when it ships.
In the meantime: PNG to WebP, JPG to WebP
How conversion will work
- Step 1
Select your ICO files
Click the upload area or drag and drop one or more ICO files. Multiple files supported.
- Step 2
Convert
Click convert. Each ICO is decoded; the largest variant is extracted and re-encoded as WebP.
- Step 3
Download
Download each result individually. The WebP carries the full alpha channel from the source ICO.
How ICO-to-WebP conversion works
An ICO file is a container that holds multiple image variants at different sizes (16×16 through 256×256) and colour depths. Each variant inside the ICO is stored either as a raw BMP bitmap (older convention) or as an embedded PNG (modern convention, used for 256×256 variants).
The conversion parses the ICO container header to find each variant, extracts the largest one (typically 256×256 if present), decodes it to RGBA pixels, and re-encodes as WebP using either lossless or lossy mode. Transparency is preserved — both modern ICO formats and WebP support 8-bit alpha.
For older ICOs that use 16-colour or 256-colour indexed palettes, the converter still produces a full-colour WebP output. The conversion can't add information that wasn't in the source, but the output format isn't constrained by the source palette either.
For format detail, see ICO Format overview, WebP format overview, and the PNG Format page (often the better destination for icon work).
When to convert ICO to WebP
Extracting icons for design work
When you need the icon graphic in a modern design tool (Figma, Sketch, Affinity), extracting to WebP (or PNG) gives you a tool-friendly file.
Migrating legacy brand assets
Brand assets locked inside .ico files are awkward to use in modern workflows. Extracting to WebP or PNG makes them portable.
Web app manifest icons
Progressive Web App manifests reference PNG or WebP icons, not ICO. Extracting from an existing favicon library is often the easiest path.
Documentation and presentations
Embedding an ICO directly in a document or slide deck rarely works. Convert to WebP or PNG first.
Cross-platform icon sets
macOS uses .icns, Linux uses .png variants, the web uses .svg or .ico. Extracting from ICO to a portable format starts a cross-platform icon migration.
Vector reconstruction reference
If you have only an ICO source and need to reproduce a vector logo, extracting the highest-resolution variant gives you a working reference for tracing in Illustrator.
File size and variant extraction
Multi-variant ICO files contain icons at multiple sizes. The converter picks the largest variant for output. Typical sizes inside a modern ICO:
| ICO contents | Extracted size | WebP output |
|---|---|---|
| 16, 32, 48 only (older ICO) | 48×48 | ~2–4 KB |
| 16, 32, 48, 64, 128, 256 (modern ICO) | 256×256 | ~8–25 KB |
| Single 256×256 variant | 256×256 | ~8–25 KB |
For systematic guidance on encoding icons, see WebP Compression Settings — lossless mode is almost always correct for icon content.
Common issues and solutions
Output is small (16×16 or 32×32)
Your ICO only contained small-size variants. The converter extracts the largest available; if the source maxes out at 32×32, that's the output size.
Transparency is missing
Older ICO files (pre-Vista era) used 1-bit transparency masks rather than true alpha channels. The WebP output preserves whatever transparency the source actually had.
Colours look quantised or dithered
Source ICO used a 16-colour or 256-colour indexed palette. The conversion is faithful to what the ICO actually contained — the limitation is in the source.
I want all variants from the ICO, not just the largest
Use a dedicated tool: icoutils (icotool -x file.ico) or ImageMagick (convert file.ico file-%d.png) extracts each variant separately.
ICO file failed to parse
The file may not be a valid ICO. Check the file extension matches its actual format — a renamed file isn't necessarily a real ICO.
I want to create a new favicon from a WebP
Use the reverse direction: WebP to ICO converter to generate multi-size favicons from a single WebP source.
Frequently asked questions
Related resources
Container structure, multi-variant storage, and current favicon-and-icon relevance.
PNG is often the better destination for icon content headed outside the browser.
Squeeze the extracted icon further by re-encoding the WebP at a different quality setting.