A .ico file is the icon format Windows and web browsers use for favicons, and a PNG to ICO converter turns a single PNG image into one .ico file that holds several sizes at once. The converter below reads your PNG on your device, redraws it at each size you select, and packs the results into a standard .ico file you can download. Nothing is uploaded.
What an .ico File Is and Where It Is Used
An .ico file is an image container built for icons. Unlike a PNG or JPG, which holds one picture at one resolution, an .ico file can store the same icon at multiple sizes inside a single file. It is the original favicon format, and every browser still reads a file named favicon.ico at the root of a website. Windows also uses .ico for application icons, shortcuts, and folder icons. When you save a .ico that contains 16, 32, and 48 pixel versions, the software that displays it chooses the size that fits the spot it needs to fill.
How to Use It
- Click the file field and choose a square PNG. A source image of 256 by 256 pixels or larger gives the cleanest result at every size.
- Check the sizes you want inside the .ico file. The 16, 32, and 48 pixel sizes are on by default, which covers most favicon needs.
- The tool redraws your image at each size and shows a preview thumbnail for every one.
- Click Download .ico to save the file. Rename it to favicon.ico if you are using it as a website favicon.
- Upload the file to your site root, or set it in your theme, so browsers can find it.
Why .ico Holds Multiple Sizes
Recommended Sizes
For a website favicon, include 16, 32, and 48 pixel versions. That set covers browser tabs, bookmarks, and the larger sizes Windows uses for shortcuts. Add 64 when you want extra sharpness for high-resolution displays.
| Size | Where it is used |
|---|---|
| 16 x 16 | Browser tab and address bar |
| 32 x 32 | Bookmark bar and taskbar shortcuts |
| 48 x 48 | Windows desktop and shortcut icons |
| 64 x 64 | High-resolution displays and large icon views |
.ico vs PNG Favicons
Modern browsers accept a PNG favicon through a link tag in the page head, and many sites use a set of PNG files at different sizes. The .ico format still has one advantage: a single file holds every size, and a browser will find favicon.ico at the site root with no markup at all. A common setup uses both, a favicon.ico for the default lookup and a few PNG sizes declared in the head for higher resolutions. If you want one file that works everywhere with the least configuration, the .ico is the simpler choice.
Runs in Your Browser
This converter uses the Canvas element built into your browser to redraw the image and a small encoder to assemble the .ico file. Your PNG is read on your own device and the .ico is built there too, so the image is never sent to a server, logged, or stored anywhere. You can run the tool with your network disconnected and it still works.
When to Use It
Use this tool when you need a favicon.ico for a website, an icon for a Windows application or shortcut, or any place that asks for a .ico file. Starting from a clean, square PNG with a transparent background gives the best result, because the icon then sits well on tabs and toolbars of any color.
Last Thoughts on Making a .ico File
Turning a PNG into a .ico is a small step with a clear payoff: one file that keeps your icon sharp in a browser tab, a bookmark, and on the desktop. The format earns its place by storing several sizes at once, which is why a single favicon.ico still covers most of what a site needs.
Build your favicon above, then explore the rest of our free online tools. If you need ready-made favicon sizes, try the favicon generator; to switch image formats first, use the image converter or the SVG to PNG converter.
Key Takeaways:
- An .ico file is the icon format for favicons and Windows icons, and it can hold several sizes inside one file.
- Include 16, 32, and 48 pixel versions for a favicon, and add 64 for high-resolution displays.
- A multi-size .ico stays sharp in tabs, bookmarks, and shortcuts because each spot gets a copy drawn at its own size.
- Start from a square PNG of 256 pixels or larger for the cleanest result, ideally with a transparent background.
- This converter runs entirely in your browser using Canvas; your image is never uploaded.
- Name the file favicon.ico and place it at your site root for browsers to find it automatically.
Frequently Asked Questions (FAQs)
What is a .ico file used for?
A .ico file holds icons. Browsers use it for the favicon that shows in a tab and bookmark, and Windows uses it for application icons, shortcuts, and folder icons. Its main feature is that one file can store the same icon at several sizes, so the right resolution is shown in each place.
What sizes should a favicon .ico include?
Include 16, 32, and 48 pixel versions. The 16 pixel size fills the browser tab, 32 covers bookmarks and taskbar shortcuts, and 48 is used by Windows for desktop icons. Add a 64 pixel version when you want extra sharpness on high-resolution screens.
Is my image uploaded when I convert it?
No. The conversion happens entirely in your browser using the Canvas element. Your PNG is read on your device, redrawn at each size, and packed into the .ico file locally. Nothing is sent to a server, so you can run the tool even with your network disconnected.
Can I use a PNG as a favicon instead of a .ico?
Yes. Modern browsers accept a PNG favicon declared with a link tag in the page head. The .ico format still has the advantage that a single file holds every size, and browsers find favicon.ico at the site root with no markup. Many sites use both for the widest coverage.
What size should the source PNG be?
Use a square PNG that is at least 256 by 256 pixels. Starting larger than the icon sizes you need means each smaller version is drawn down from a clean source, which keeps edges sharp. A transparent background helps the icon sit well on tabs and toolbars of any color.
How do I install the .ico file as a favicon?
Rename the downloaded file to favicon.ico and upload it to the root folder of your website. Browsers look for that path automatically. If your theme or platform has a favicon setting, you can upload the file there instead, and it will add the needed link tag for you.
