AVIF stores still or animated images using AV1 compression in a HEIF container.
ICO stores a raster icon for Windows applications and browser favicons.
The source is decoded as one image.
Alpha transparency is retained when it is present in the decoded source pixels.
The destination encoder can change pixel values, bit depth, color representation, or file size.
ICO output is limited to a single image no larger than 256 by 256 pixels.
The worker applies EXIF orientation, converts pixels to 8-bit sRGB, and removes source metadata before encoding.
ICO is used for Windows application icons and is accepted by browsers for favicon files. A square AVIF source with a clear subject usually works better than a wide photograph. Crop the image before conversion when the important artwork would become too small or sit off center.
The private image worker decodes the AVIF, removes source metadata, writes ICO output, and validates the generated file signature. Conversion changes the file format. It does not add missing detail or redesign artwork for small interface sizes.
Confirm that transparent areas remain suitable for both light and dark backgrounds. Thin lines, small text, gradients, and photographic detail can become unclear at favicon scale even when the output is a valid ICO file.
Open the icon in its destination and inspect it at 16 by 16, 32 by 32, and any larger size the application requires. This route does not promise that one ICO contains every common icon size, so verify the dimensions written by the selected conversion settings.
Set an optional width or height, preserve or change the aspect ratio, and choose output quality. Transparency is retained when the destination supports it.
One image is processed per request. Animated WebP, GIF, and multi-page TIFF retain all frames only when the destination also supports multiple frames. The input limit is 25 MB.
The web application validates the file before forwarding it to a private worker. The worker validates the signature again, processes the file inside a unique temporary directory, validates the output, and removes the job directory in a guaranteed cleanup path. Files are not written to the database or retained for analytics.
When you import from a URL, the application fetches only a validated public HTTP or HTTPS address, checks the downloaded file in memory, and applies the same worker cleanup rules. The URL, filename, and file contents are not sent to analytics.