ICO – Windows Icon
ICO is the Windows icon format, and browsers also use it for favicons. A single .ico file can hold several sizes of the same icon, from 16x16 up to 256x256, so the right one is shown wherever it is needed.
More ICO conversionsDrop your ICO files here
or click to choose ICO files · up to 95MB each
How to convert ICO to AVIF
- Choose your files. Click Select File or drag your ICO files into the upload box. You can add many at once.
- Pick the settings. AVIF is already selected as the output format. Adjust Quality and Max dimension if you want smaller files.
- Download. Each file appears in the list when it is ready. Download them one by one, or all together with Download all.
AVIF – AV1 Image File Format
AVIF is a modern image format built on the AV1 video codec. It supports transparency and high dynamic range, and it often produces the smallest files of any web image format at a given quality. Encoding is slower than for JPG or WebP, and older browsers and some apps cannot open it.
More AVIF conversionsICO vs AVIF
| Feature | ICO | AVIF |
|---|---|---|
| Full name | Windows Icon | AV1 Image File Format |
| Compression | PNG or BMP images inside | Lossy and lossless |
| Transparency | Yes | Yes |
| Animation | No | Yes |
| Introduced | 1985 | 2019 |
| Developed by | Microsoft | Alliance for Open Media |
| Best for | Favicons and Windows icons | The smallest web images in modern browsers |
Converting ICO to AVIF
- AVIF often gives the smallest files, but older browsers and some apps cannot open it, and it takes longer to create.
Frequently asked questions
How do I convert ICO to AVIF?
Click Select File or drop your ICO file onto the upload box. Pick the quality and maximum size, and the converted AVIF appears in the list below with a download button. You can add many files at once and download them together as a ZIP.
Is it really free?
Yes. There is no sign-up and no watermark. To keep the service available for everyone there is a 95MB limit per file and a cap on how many files one connection can process in a short period.
Are my files stored?
Your upload is used only to make the converted file. Images are processed in memory; other files are written to a private temporary folder that is deleted as soon as the conversion finishes. Nothing is kept after the result has been sent back.
Will quality drop?
For images, a little, by design: the image is re-encoded at the Quality you choose (default 75%). Audio and video are re-encoded with high-quality settings; documents keep their text and layout as far as the target format allows. Converting never restores detail that is already missing from the original.
How this works: your file is uploaded over HTTPS and converted on this server with open-source engines (libvips for images, FFmpeg for audio and video, LibreOffice and Pandoc for documents, Calibre for ebooks, Ghostscript and Inkscape for PDF and vector files). Images are processed in memory; other files use a private temporary folder that is deleted as soon as the conversion finishes.