Converting ICO to AVIF produces a highly compressed image file from the largest icon with full alpha support. For icon imagery destined for modern web delivery, AVIF provides the smallest files.
Drag & drop image files here, or browse
Drop your ICO files here
Encoding is slower than PNG or WebP. Lossless AVIF preserves exact pixels; lossy AVIF at high quality is visually indistinguishable. Alpha transfers cleanly. Only the largest embedded icon size is converted.
AVIF works in Chrome 85+, Firefox 93+, Safari 16+, modern Edge, macOS, and iOS.
ICO is the Windows icon format. A single .ico file can hold multiple resolutions (16×16, 32×32, 48×48, 256×256) and color depths simultaneously, letting the OS pick the best for context. Every browser serves favicons as ICO, and Windows desktop icons use it natively.
AVIF is an image format built on the AV1 video codec, standardized in 2019. It supports HDR, wide color gamut, 12-bit depth, alpha, and animation. At matched perceived quality it's typically 50% the size of JPG and 20% smaller than WebP. Support is near-universal in modern browsers but spottier in image editors.
For individual small icons the savings are minimal; AVIF's efficiency scales with image size. For larger icon assets (256×256 with rich detail), AVIF produces noticeably smaller files.
The largest size in the ICO, typically 256×256.
ICO is the Windows icon format. A single .ico file can hold multiple resolutions (16×16, 32×32, 48×48, 256×256) and color depths simultaneously, letting the OS pick the best for context. Every browser serves favicons as ICO, and Windows desktop icons use it natively.
AVIF is an image format built on the AV1 video codec, standardized in 2019. It supports HDR, wide color gamut, 12-bit depth, alpha, and animation. At matched perceived quality it's typically 50% the size of JPG and 20% smaller than WebP. Support is near-universal in modern browsers but spottier in image editors.
Yes. The converter runs entirely in your browser using WebAssembly. Your images are never uploaded, never sent to a server, and never leave your device.
There's no hard limit, but because everything runs in your browser you're bounded by available memory. Very large images (over a few hundred megapixels) can hit browser memory limits. Process in smaller batches if you run into issues.