How to use the PNG to ICO tool
- Tick the icon sizes you want (16, 32 and 48 are the essentials).
- Drop a square PNG or JPG into the box.
- Check the previews of each size.
- Press Download ICO to save the file.
What an ICO file is
An ICO file is a small container that holds the same icon at several sizes. Windows and browsers pick the size that suits the place it is shown: 16 x 16 in a browser tab, 32 x 32 on a taskbar, 48 x 48 in a folder view, and up to 256 x 256 on high-resolution desktops. One .ico file covers them all.
Making a favicon
For a website favicon, include 16, 32 and 48 pixel sizes and name the file favicon.ico. Upload it to the root folder of your site, the same folder as your home page, and most browsers will find it automatically. You can also reference it in your page head with a link tag. Modern sites often add a PNG or SVG icon as well, but the .ico remains the most compatible fallback.
Start with a good image
Use a square image of at least 256 x 256 pixels with a simple, bold design. Fine detail and small text disappear at 16 pixels, so logos with a single letter or symbol work best. If your image is not square, the converter crops it from the center; crop it yourself first with the crop tool if you want a different area.
Transparency
Transparent backgrounds in your PNG are kept in every icon size, so the icon sits neatly on light and dark browser tabs. JPG images have no transparency and will keep their background color.
Compatibility
Each size is stored as a compressed PNG inside the ICO, a method supported by Windows Vista and newer and by all current browsers. This keeps the file small, typically a few kilobytes up to around 50 KB with the 256 pixel size.
Private and instant
The icon is generated in your browser. Your logo is never uploaded, which is useful when you are working on unreleased brand assets.
Tip
Name it favicon.ico for websites.
Testing your favicon
After uploading favicon.ico to your site, open the site in a private browser window to bypass the cache and check the tab icon. Browsers cache favicons aggressively, so an old icon may stay visible for a while in your normal window.
Frequently asked questions
What sizes should a favicon ICO have?
16 x 16, 32 x 32 and 48 x 48 are the essentials. Add 256 x 256 for Windows desktop icons.
Can I convert JPG to ICO?
Yes. JPG, PNG and WebP images are accepted.
Does the ICO keep transparency?
Yes, transparent PNG areas stay transparent.
Does it work as a Windows icon?
Yes, the files work on Windows Vista and newer.
Is my logo uploaded?
No, it is processed in your browser.