AVIF → ICO Converter

Drag & Drop your .avif file here, or pick a file below. Nothing is uploaded.

Tip: AVIF decode support is required. Most modern browsers support AVIF. If your file won't preview, try a different browser.

Icon sizes to include

PNG-compressed entries inside .ico; transparency preserved.

Optional background (only affects preview)

ICO preserves alpha by default here; this is just for preview contrast.

Load an AVIF to preview.

Input: -

ICO entries: -

AVIF → ICO - Quick Cheat Sheet

Local only: Conversion runs in your browser; files aren't uploaded.
ICO contents: This tool writes a valid ICO with PNG-compressed entries (recommended; widely supported).
Sizes: Include 16/32/48 for legacy favicons; add 64/128/256 for HiDPI.
Transparency: Preserved (alpha channel kept in PNG entries).
Color profile/EXIF: Browser canvas may drop some metadata; ICO typically stores image data only.
Legacy BMP ICO: Needed only for very old software; not included by default.

How the ICO is built

We decode the AVIF, scale to the selected sizes, encode each as PNG, then pack them into one .ico file.
ICO header: ICONDIR (6 bytes), then one ICONDIRENTRY per size, followed by the PNG byte streams.
Directory width/height fields are 1 byte (0 means 256).