What's the difference between ICO and AVIF?

ICO is the Windows icon format and the classic home of the site favicon.ico. AVIF is the newest mainstream image format, built on top of the AV1 video codec.

Will I lose quality converting from ICO to AVIF?

Yes — AVIF discards some image detail in exchange for much smaller files. At quality 80 or above the difference is usually invisible to the eye. For maximum quality, use quality 90+. For maximum compression, drop to quality 70 (still acceptable for most photos).

What quality should I pick?

For AVIF, quality 75-85 is the sweet spot — small files with no visible difference from the original. Lower than 60 starts to show artifacts. Higher than 90 mostly just makes the file bigger.

When is AVIF the right format?

AVIF is a good choice for: hero images and other content where every byte matters; build-time image pipelines that can absorb the encoding cost; photos with smooth gradients (the AV1 codec excels here). It is a poor choice when on-the-fly conversion where the user is waiting (slow encode).

Anything surprising about ICO or AVIF?

Modern .ico files embed PNG frames; convert.now packs a single PNG frame per icon. And on the AVIF side: AVIF encoding is single-threaded by default — large images can take 5–10 seconds in browser.

Does this work on mobile?

Yes. The drop zone falls back to your phone's file picker, and conversions run on-device just like desktop. Large files may be slower on mobile due to CPU and memory constraints, but the workflow is identical.

What's the maximum file size?

No hard limit — the browser handles it. Files under 50MB convert in a few seconds. Larger files work but may take longer as the browser allocates memory. If you hit issues, batch in smaller groups.

Convert ICO to AVIF

Convert ICO to AVIF, typically the smallest of the modern web formats. The largest resolution in the icon is used. Free, in your browser.

Drop images to convert

PNG, JPG, WebP, AVIF, JPEG XL, TIFF, BMP, GIF, SVG, HDR, ICO — any combination

Files stay on your device. Open DevTools' Network tab to verify.

Output format

AVIF

Quality82%

Overview

Why convert ICO to AVIF

AVIF is a more practical choice than ICO for most modern workflows: hero images and other content where every byte matters. Coming from ICO, the thing to know is that photographs and general web images (use WebP, JPG, or PNG).

Comparison

ICO vs AVIF: what actually differs

ICO compared with AVIF across encoding, fidelity, file size and support.
Attribute	ICO	AVIF
Compression	Lossless	Lossy
Transparency	Yes	Yes
Animation	No	Yes
Typical file size	Varies	Small
Browser support	Universally supported as a favicon — every browser reads .ico. Not used for general on-page images.	Supported in Chrome, Firefox, Safari 16+, and Edge. Pre-2022 devices may not decode it.

How to

How to convert ICO to AVIF

01
Drop your ICO files
Drag one or more ICO files onto the dropzone above, or click to browse. Files stay on your device — nothing uploads.
02
Convert in your browser
convert.now decodes each ICO and re-encodes it as AVIF via WebAssembly. The conversion runs in a Web Worker so the page stays responsive.
03
Download the result
Download a single AVIF file or, for batch conversions, a zip of all converted files. Filenames preserve the originals.

Why here

Why convert.now

Private
Files stay in your browser. No upload step. Nothing for anyone to see.
Fast
No queue, no upload wait. Conversion starts the moment you drop a file.
Free
No ads. No file-count limit. No sign-up wall. Just the converter.

FAQ

ICO to AVIF: common questions

No. The conversion from ICO to AVIF runs entirely in your browser using WebAssembly. Files never leave your device. Open DevTools' Network tab if you'd like to verify — there are no network requests with file contents.

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Last updated 27 August 2026

Why convert ICO to AVIF

ICO vs AVIF: what actually differs

How to convert ICO to AVIF

Drop your ICO files

Convert in your browser

Download the result

Why convert.now

ICO to AVIF: common questions

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