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256×256 ICO Icon Maker

Generate high-resolution 256×256 pixel icons for Windows 11, Windows 10, and 4K display scaling.

100% Free No Signup No Watermark Private In-Browser
Drop an image here
or choose a file from your device
Supports PNG, JPG, WebP, GIF, BMP (Max 4 MB)

The 256×256 Standard in Modern Windows

Introduced in Windows Vista and foundational across Windows 10 and 11, 256×256 is the largest standard icon resolution in Windows. It powers "Extra Large Icons" in File Explorer, Start menu live tiles, and 4K desktop scaling.

Microsoft 0-Byte Dimension Convention

According to the official Microsoft ICONDIRENTRY specification, because a single byte can only represent numbers 0–255 (0xFF), width and height values of 256 pixels are encoded as byte value 0. Imgora implements this exact binary encoding convention.

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Frequently Asked Questions

Technical answers regarding 256×256 ICO Icon Maker.

An uncompressed 256×256 32-bit bitmap requires over 262 KB of raw data. Using PNG encapsulation inside the ICO container reduces the frame size by ~85% with zero quality loss.
Yes. You can toggle on 16, 32, 48, 64, or 128 px checkboxes to bundle all resolutions into a single file.