Transparent ICO Generator
Pack any image into a transparent one-size .ico — real container format, built locally.
Drop an image here or click to browse
Files never leave your browser
How to use
- Drop a square-ish image (PNG with transparency works best) or click to browse.
- Pick one size — 16 px is the classic favicon; 32/48 stay sharp in taskbars and high-DPI tabs.
- Press Generate ICO, then download the .ico file.
Frequently asked questions
What is an ICO file and why do I need one?
ICO is the container format Windows and browsers expect for favicons and desktop shortcuts. Modern browsers accept PNG favicons, but a .ico in the right size is still the safest way to look sharp everywhere, including taskbars and bookmark bars.
What does the .ico file contain?
Exactly one image at the size you selected: a 6-byte ICONDIR header whose image count is 1, a single 16-byte directory entry (width, height, 32-bit color, byte length, data offset), then the PNG data. You can verify the structure in any hex editor.
Does transparency survive?
Yes. The image is encoded as PNG with its alpha channel intact, so see-through corners in your source image stay see-through in the .ico.
Is my image uploaded?
No. Files never leave your browser — the scaling, PNG encoding and container packing all happen in your tab.
Which size should I pick?
16 px is the classic favicon size; 32 px looks better in taskbars and browser tabs on high-DPI screens; 48 px and up suit desktop shortcuts and app listings. The file holds one size, so if you need several sizes, generate one .ico per size.