ICO → AVIF Converter

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

Note: Multi-size ICOs will decode to one embedded size (browser-chosen).

Output width (px)

Blank = use decoded ICO width (or maintain aspect when only height is set).

Output height (px)

Blank = compute from width using aspect ratio.

AVIF quality (0-1)

Higher = larger file, potentially better detail.

Background

Keep transparency

Uncheck to flatten onto a solid color before encoding.

Load an ICO to preview here.

Decoded size:

Output size:

ICO → AVIF - Quick Cheat Sheet

Privacy: Everything runs locally in your browser-no files are uploaded.
Browser support: AVIF export requires a browser that supports encoding to image/avif. If not supported, this tool will tell you.
ICO specifics: ICO files can contain multiple sizes/bit depths. Browsers generally decode one size (often the largest); this tool uses whatever the browser decodes.
Sizing: Set width and/or height. If only one is set, the other is computed to keep aspect ratio. Leave both blank to use the decoded size.
Transparency: AVIF supports alpha. Keep transparency on, or uncheck to flatten against a chosen background color.
Quality: AVIF quality is 0-1. Start at 0.8 for balance; raise for crisp UI icons, lower for smaller files.
CORS note: Loading remote images or file:// paths may fail due to security rules-use local file pick/drag-drop.

Troubleshooting

"AVIF not supported": Try the latest Chrome, Edge, Firefox, or Safari 16+.
"Failed to decode ICO": Some browsers can't decode certain ICO variants. Converting ICO ? PNG first may help.
Huge sizes: Extremely large outputs can exhaust memory. This tool caps canvas dimensions for safety.