The container and image size are different
An icon file may contain multiple small images so a system can choose a suitable size. It may instead contain one PNG-backed image. Different programs accept different combinations, so “ICO supported” is not a promise that every legacy, palette-based or compressed variant can be decoded. Inspect the embedded image and the receiving program’s documentation.
Tool Fera’s ICO to PNG/JPG tool selects the largest directory entry. It supports PNG-backed images and uncompressed 24/32-bit DIB icons. It does not export a ZIP of all embedded sizes. If an unsupported variant fails, use an icon editor that supports that encoding rather than renaming the file to PNG.
Prepare square artwork without distortion
Icons normally occupy a square pixel grid. A rectangular photograph squeezed into that grid will distort the subject. Crop the useful region first when a square composition is intended, or fit the rectangle inside a square with empty space around it. Empty space can be transparent, but a JPG source cannot supply alpha that it never contained.
The PNG/JPG to ICO tool fits artwork proportionally into a transparent square without cropping. Choose 32, 64, 128 or 256 pixels under Optional settings. The output contains one PNG-backed entry at that size. Use Image Cropper first when letterboxing is not the desired composition.
Judge the icon at the size people will see
A detailed logo that looks attractive at 256 pixels may become unreadable at 32. Small lettering, fine outlines and closely spaced shapes can merge. Resampling creates a smaller pixel grid; it cannot preserve every feature from a large illustration. Look at the icon at normal display scale, not only in a large preview.
A large PNG can provide a better source for downscaling than a small extracted icon. Enlarging a 32-pixel image to 256 pixels does not recreate lost detail. For a site favicon, check the sizes and link declarations expected by that site’s implementation. This converter creates an image file, not a complete favicon manifest, browser configuration or multi-platform icon package.
Transparency and compatibility require separate checks
PNG-backed ICO artwork can contain alpha transparency. That is useful for rounded or irregular symbols, but a viewer may display the icon against white or black. Test it on a contrasting surface to distinguish real transparency from the viewer’s background. The transparency guide explains why a white preview alone is inconclusive.
A legacy application may require a DIB-backed or indexed icon rather than the PNG-backed output produced here. A successful independent image decode does not prove that every Windows version or embedded application accepts the file. Check the required variant before uploading it, and keep the source artwork so another icon encoder can produce that variant if needed.
Check the delivery file rather than its name
Open the downloaded ICO in the destination and confirm the embedded dimensions. If the application asks for several sizes in one container, this single-entry output is insufficient even if it looks correct in an image viewer. Choose a dedicated multi-size icon editor for that requirement. Tool Fera does not claim multi-size or universal legacy compatibility.
When extracting an ICO to a familiar image, PNG is usually useful for retaining alpha. JPG fills transparent areas with a selected solid color and is better treated as an opaque delivery copy. The original ICO’s other images are not carried into either still result. Keep the original container if its full size set or specialized encoding matters.
Inspect which image an ICO contains and which variant the recipient accepts. Tool Fera extracts the largest supported entry and creates one PNG-backed square at a selected size. These are useful, bounded operations rather than a complete multi-size icon editor.