A single size can make an icon look wrong. Windows uses different sizes in different places, so it stretches or shrinks a file that contains only 48 x 48. Microsoft's icon design guidance on Microsoft Learn lists the sizes a desktop icon should ship.

• 16 x 16 for the system tray, small list views, and the title bar
• 32 x 32 for the default desktop icon
• 48 x 48 for medium icons in File Explorer
• 256 x 256 for large icons and high-DPI displays (stored PNG-compressed inside the ICO)

Icon Maker preserves the source PNG's alpha channel during conversion. The transparency must already exist in the PNG; adding it afterward requires manual masking. Some older PNG to ICO Converter Software flatten a smooth alpha edge into a hard 1-bit cutout. Save the ICO at 32-bit color to keep the soft edges. If you only have a JPG with a baked-in background, clean it first or follow our JPG to ICO converter walkthrough.

Color depth controls the colors and transparency each layer can hold. Windows 10 and 11 expect 32-bit, with eight bits per channel plus an 8-bit alpha channel. Legacy 8-bit (256-color) and 4-bit (16-color) depths use a single on-or-off transparency bit. PNG to ICO Converter Software lets you set the output depth, including a legacy 8-bit version when needed.

The favicon.io guide on favicon sizes recommends at least 16 x 16 and 32 x 32, with 48 x 48 as an extra for Windows site shortcuts. Select those small sizes, name the output favicon.ico, and put it in your site root. Browsers find it automatically; a link tag in the page head can also point to it.

Icon Maker converts every PNG in a folder into its own ICO, using the same size set for the batch.

• Click Add Folder and select the directory of PNG sources
• Set the output sizes and format (ICO) once for the whole batch
• Pick a destination folder
• Click Start, and the program writes one ICO per source PNG

If the project also needs different pixel dimensions for other assets, our image size converter guide covers that work.

Windows uses ICO for desktop shortcuts, folder icons and Control Panel entries, choosing the closest size from the bundle. A Windows application embeds an ICO as its program icon, which appears in the taskbar and the Alt+Tab switcher. A dedicated Windows icon maker writes these from one source.

An online converter uploads the file to someone else's server. A Microsoft forum thread about converting on a PC for free includes a comment asking "who knows what kind of data harvesting or malware might be lurking" (techcommunity.microsoft.com). A desktop converter keeps the file on your machine.

Online tools often output a single size or fixed depth. A desktop converter lets you choose the sizes, set the color depth, and run a batch offline. With SoftOrbits Icon Maker, the job stays on your machine.

SoftOrbits Icon Maker reads PNG, JPG, and other common raster formats. It exports ICO and ICL plus cursor (.cur / .ani) formats, extracts icons from EXE, DLL, and ICL files, and includes a pixel editor for cropping, recoloring, and touch-ups.