Are my ICO files uploaded to a server?

No. The entire conversion runs inside your browser using the HTML5 Canvas API. Your ICO file never leaves your device.

Which browsers support AVIF encoding?

Chrome 85+, Edge 85+, and Firefox 113+ support AVIF encoding via the Canvas API. Safari can display AVIF images but does not yet support Canvas-based AVIF encoding. If the tool shows an error, try Chrome or Edge.

Does AVIF support transparency from the ICO?

Yes. ICO images often include an alpha channel. The Canvas API preserves alpha, and AVIF fully supports transparency, so the output will retain any transparent areas from the original icon.

How many sizes can an ICO file contain?

An ICO file can embed any number of images at different sizes. Common favicon sizes are 16×16, 32×32, 48×48, and 256×256 pixels. Windows application icons may also include 24×24, 64×64, and 128×128.

What quality setting should I use?

Quality 70–80 is an excellent sweet spot for most icons — visually near-lossless at significantly smaller file sizes. For simple flat-color icons, use 85+ to preserve sharp edges. For thumbnails, 50–65 is acceptable.

Why might the AVIF be larger than the original ICO?

Very small icons (16×16 or 32×32) with simple flat colors compress extremely well with lossless encoding. AVIF lossy encoding at high quality can occasionally be larger for such tiny images. Try lowering the quality slider for better compression.

ICO to AVIF Converter

Name: ICO to AVIF Converter
Availability: InStock
Author: Nham Vu

Upload an ICO file, pick a size and quality, and download the AVIF — all processed locally in your browser, nothing sent to a server.

Upload ICO File

Click or drag an ICO file here

ICO / favicon files — converted to AVIF in your browser

AVIF Preview

Upload an ICO to see the embedded sizes

Conversion to AVIF happens instantly, entirely in your browser

Downloaded!

Summary

Upload an ICO file, pick a size and quality, and download the AVIF — all processed locally in your browser, nothing sent to a server.

How it works

Upload any ICO or favicon file by clicking the upload area or dragging it in.
The browser reads the ICO binary and decodes each embedded image size using the Canvas API.
A grid of available sizes appears — click any tile to select that resolution.
Adjust the AVIF quality slider to balance clarity against file size.
A live AVIF preview and file-size comparison are shown instantly.
Click "Download AVIF" to save the converted image to your device.

Use cases

Convert a high-resolution ICO frame to AVIF for use in modern web projects.
Reduce icon file sizes significantly compared to PNG or WebP.
Prepare favicon assets in next-generation AVIF format for better performance.
Extract and convert individual icon sizes from a multi-size ICO.
Convert Windows application icons to AVIF for cross-platform use.
Process icons privately without uploading to a third-party service.
Preview all sizes embedded inside an ICO before deciding which resolution to export.
Optimize icon assets for Android, iOS, or web manifests that accept AVIF.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu