PNG → ICO Converter

Drag & Drop your .png here, or pick a file below. Nothing is uploaded.

Icon sizes (px)

Tip: For Windows app icons, include 16, 24, 32, 48, 64, 128, 256 px.

Output filename (without extension)

Defaults to the uploaded file's base name, or favicon.

Load a PNG to see thumbnails of resized icons.

PNG → ICO - Quick Cheat Sheet

Transparency: ICO supports alpha. PNG transparency is preserved in the ICO entries.
Multiple sizes: A single .ico can contain multiple images. Windows and browsers auto-pick the best size.
Recommended set: 16, 24, 32, 48, 64, 128, 256 px covers most desktop/app cases. For web favicons, 16/32/48 px are commonly used.
Source quality: Start from a large, crisp PNG (e.g., 1024x1024) to avoid blurriness when downscaling.
File structure: This tool writes a valid ICO: ICONDIR header + ICONDIRENTRY table + PNG image data for each size (Windows accepts PNG-compressed entries).
Privacy: 100% local. Your image never leaves the browser.

ICO specifics (for the curious)

ICONDIR = 6 bytes: reserved=0, type=1 (icon), count=N.
Each ICONDIRENTRY = 16 bytes with width/height, planes, bit count, size, and offset.
Width/height bytes store 0 for 256 px (ICO quirk); others store the literal pixel size.
Image data can be PNG (modern) or DIB/BMP with AND mask (legacy). This tool uses PNG data for compatibility and smaller files.