ICO to WEBP Converter
Convert ICO (Windows Icon, 1985) to WEBP (WebP, 2010) entirely in your browser. Output files are dramatically smaller — typically around 88% the size for ordinary photographs. Files never leave the tab — there is no upload.
Which formats are supported?
Inputs: PNG, JPEG, WEBP, AVIF, GIF, BMP, ICO, TIFF (Safari) and HEIC/HEIF (via libheif WASM, loaded on demand). Outputs: PNG, JPEG, WEBP, AVIF — each with an optional WASM encoder variant in the dropdown (mozjpeg, oxipng, libwebp, libavif) for tighter compression or consistent output across browsers. Vendor camera RAW formats (CR2/CR3/NEF/ARW/DNG/...), PSD, EPS, TGA, XCF and ICNS are still rejected — those need format-specific decoders we haven't shipped yet.
Both formats default to lossy encoding for photographs. We use the default quality setting (92) which preserves visually-identical detail for most images. Drop the slider lower for hero images on slow connections, raise it for printable masters.
Both formats support a true alpha channel — anti-aliased logos, drop shadows and translucent overlays survive the round-trip unchanged.
WEBP is the natural choice for Web delivery where AVIF is too aggressive, Replacing both JPEG and PNG with a single format, and Animated graphics under 5MB. It is a poor fit for Email attachments and Sending to non-technical end users who'll re-share the file. All current browsers; not safe for email or legacy enterprise software.
ICO: what it is
An ICO is a container holding multiple raw or PNG-encoded images at different sizes (16, 32, 48, 256 …). We extract the largest one when you drop one in.
Browsers still load favicon.ico for backwards compatibility, but new sites should ship PNG or SVG favicons referenced from the manifest.
WEBP: what it is
Lossy WEBP uses VP8 intra-frame coding (the same predictor system as the VP8 video codec). Lossless WEBP is a separate algorithm that beats PNG on most images.
Typical lossy WEBP is 25–35% smaller than a visually-equivalent JPEG and 50–70% smaller than the equivalent PNG.
At a glance
- Typical size change
- ~88% smaller
- Transparency preserved
- Yes — both formats support alpha channels
- Compression
- ICO (lossless) → WEBP ( both)
- WEBP browser support
- All current browsers; not safe for email or legacy enterprise software.
Frequently asked questions
Is the converted WEBP smaller than the original ICO?
On a typical photograph, dramatically smaller — typically around 88% the size. Synthetic graphics (logos, screenshots) may behave very differently — try a single file first if size matters.
Will my ICO be uploaded to convert it?
No. The conversion runs inside the browser tab using WebAssembly. Your file is never sent over the network — drop it, convert it, download it, all on your machine.
Will WEBP open in older software?
All current browsers; not safe for email or legacy enterprise software. If you need to send the file to someone using a 5+ year old version of Outlook, Word or other desktop software, convert to JPG or PNG instead.