Image to ICO

What this tool does

Image to ICO converts any raster image — typically a PNG or JPG — into a multi-resolution Windows .ico file. You choose which pixel sizes to embed using toggles — 16, 32, 48, 64, 128, and 256 are all available, with 16, 32, and 48 selected by default. The tool renders your source at each chosen size using the browser’s canvas, encodes each frame as a PNG, and packs them all into a single ICO file using the correct binary format. The result can be downloaded immediately and deployed as a website favicon or Windows application icon. Nothing leaves your device during any of this.

The same page also runs the reverse direction: switch the toggle to “ICO → PNG” and drop in any Windows .ico file to list its embedded frames and download each one as a standalone PNG.

PNG to ICO

If you started with a transparent PNG — the most common case for favicons — keep the alpha channel intact and the resulting ICO will display correctly against any background, including the dark mode many browsers now use. Use a 512×512 or larger PNG as the source for the cleanest 16×16 and 32×32 frames; a too-small source forces the encoder to upscale, which never looks as good as a downscale from a richer master.

JPG to ICO

JPG sources work too — the tool decodes the JPG, draws it at each requested size and re-encodes those frames as PNG inside the ICO container, so the embedded data is lossless even if the source was not. The trade-off: JPG has no transparency, so your icon will sit on a solid background. For photographic favicons (a photo of a logo, a portrait icon) that is fine; for geometric logo icons, save the source as PNG with a transparent background first, then run it through this converter.

Why you might need it

The .ico format is specifically designed to bundle multiple icon resolutions into a single file. When Windows displays an icon in an Explorer window, the taskbar, the Start menu, or a browser tab, it picks the resolution that best matches the display size and pixel density rather than scaling a single large image. This means a well-crafted ICO with several embedded sizes looks sharp in every context, whereas an ICO with only one size looks correct in one place and blurry or pixelated everywhere else.

For web developers, favicon.ico at the domain root is still the most reliably detected favicon format across browsers, crawlers, and RSS readers — many of which only check for /favicon.ico and do not parse the page’s <link> tags. A multi-resolution ICO at that path provides the best coverage across old and new software alike.

For application developers on Windows, the ICO is the native icon container. Electron apps, NW.js apps, and traditional Win32 or .NET executables all read ICO files directly. Embedding multiple sizes ensures the icon looks correct on standard monitors, on high-DPI displays running at 125%, 150%, or 200% scaling, and in the various Windows shell views.

How to use it

1. Drop your source image onto the upload zone, or click to browse. PNG files with transparency work best; JPEG and WebP are also accepted.
2. Use the size toggles to choose which resolutions to embed. At least one must remain selected — the tool prevents you from deselecting the last one.
3. Click Convert to ICO. The tool renders your image to a canvas at each selected size and builds the ICO file. A preview shows each embedded frame at an enlarged scale so you can see how the icon looks at each resolution.
4. Click Download .ico to save the file. The download is named after your source file with the extension replaced by .ico.

Common pitfalls

The most common issue is a source image that is not square. The tool handles this by centering the artwork in a square canvas with transparent padding, preserving the aspect ratio rather than stretching. This is usually the right behaviour, but if your icon appears to have unexpected whitespace, use an image editor to crop the source to a square before uploading.

Small sizes (16×16 and 32×32) inevitably lose fine detail. Logos with thin lines, intricate text, or many small elements will look muddy at 16 pixels regardless of source quality. If the preview at 16×16 is not legible, consider a simplified version of the icon — a monogram, a bold geometric shape, or just the primary colour fill — for those small sizes. You can also make a focused favicon bundle using the Favicon Generator tool, which lets you use a single source and handles HTML link tags at the same time.

The 256×256 frame significantly increases the ICO file size. For pure web favicon use cases (where files are served over HTTP), including 256 adds weight without much benefit, since browsers cap tab icons at 64×64 or smaller. Include 256 when the ICO will be used as a Windows application icon.

Tips for best results

Start with the highest-resolution source you have — ideally 512×512 or larger from a vector export. The canvas downscaling produces good results, but it cannot recover detail that was never in the source. Vector-originated artwork at high resolution gives the sharpest 16×16 and 32×32 frames.

After generating, check the 16×16 preview carefully. That is the size browsers display in the tab bar, address bar favicon dropdown, and bookmarks menu. If it is illegible, simplify your artwork. A single letter or a high-contrast shape is almost always more recognisable than a complex logo at that scale.

For application icons targeting Windows, include at least 16, 32, 48, and 256. Windows Explorer shows 16 in list view, 32 in small-icon view, 48 in medium-icon view, and 256 (scaled) in large-icon view. Including all four guarantees a sharp icon in every shell context.