AVIF is a next-generation format with the highest compression efficiency available. Current browsers open AVIF, but support in programs and services is uneven.
ICO is a container format for favicons and Windows icons. When you convert AVIF to ICO, you can open it in more places and it can be used as an icon or favicon. See the comparison below for what changes.
This converter reads the file itself to confirm it is AVIF, then converts it to ICO right in your browser. Your image is never uploaded.
AVIF vs ICO: what's the difference?
| Item | AVIF | ICO |
|---|---|---|
| Compression | Lossy or lossless | Lossless |
| Transparent background | Yes | Yes |
| Animation | Yes | No |
| Introduced | 2019 | 1985 |
| Support in programs and upload forms | limited | moderate |
| Shown directly in browsers | Yes | Yes |
| Photo file size (JPG = 1) | about 0.5× | n/a |
What is AVIF?
AVIF is an image format released in 2019 that builds on the still-image technology of the AV1 video codec. At the same quality it can be around 50% smaller than JPG, so websites sensitive to file size are adopting it quickly.
What is ICO?
ICO is the format used for Windows icons and website favicons. Its distinguishing feature is that one file can hold several sizes, such as 16×16, 32×32 and 256×256.
What changes when you convert AVIF to ICO
Quality doesn't improve, but it doesn't get worse either
Information lost when AVIF was saved can't be recovered. ICO is lossless, so it keeps the image exactly as it is now and later edits and saves add no further degradation. File size will grow, though.
Moving images keep only their first frame
ICO can't hold animation. If your AVIF file is animated, only the first frame is converted.
It is fitted into a square of at most 256×256
ICO is limited to 256×256. Larger images are scaled down with their aspect ratio kept, and images that aren't square are centered with the leftover area left transparent.
ICO has no quality setting
ICO is lossless, so the quality slider doesn't apply. Instead, when converting from AVIF you can manage file size by resizing (exact width and height, or a percentage).
How the file size changes
ICO holds images of up to 256×256, so a large original shrinks a lot. If the image is already small, the difference is negligible.
ICO opens in more places
Support for AVIF in programs, document tools and upload forms is limited, while ICO is moderate. If you need to upload somewhere AVIF wouldn't open, try again after converting.
When to convert
- You need to upload to a program, messenger or upload form that can't open AVIF
- You're making a website favicon or a Windows shortcut icon
- You're preparing an image for typical ICO uses (website favicons, windows program icons)