What is favicon ICO file

A favicon.ico file is a small image file that serves as a visual marker for a website. It appears in browser tabs, bookmarks, and address bars, helping users quickly identify and return to familiar sites.

Technically, favicon.ico is a special icon file created for browser use. It typically contains a 16×16 pixel icon stored in a format widely supported by web browsers. If you're asking what is favicon ico, it's simply the default file that represents a site in the browser interface.

What is an ICO file and why is it used for favicons?

An ICO file is a special icon file format that contains multiple image sizes and color depths within a single file. Originally developed for Windows systems, this format remains commonly used in web design for favicons because of its ability to include several resolutions in one package. This allows browsers to select the most appropriate version for different devices and screen resolutions. Compared to formats like PNG or SVG, the ICO format offers broader compatibility and more consistent display across various platforms, which explains its continued popularity among web developers.

Where is favicon.ico displayed and why does the browser request it?

Modern web browsers automatically search for a file named favicon.ico in a website's root directory, even when there is no explicit HTML reference to it. This request typically occurs in the background during page loading.

Favicons appear in several locations:

• Browser tabs
• Bookmarks and favorites
• Address bar and browsing history

So if you're wondering what does ico mean, in this context it refers to the standard image format used to display website icons.

Can favicons use other file formats or different file names?

While using favicon.ico represents the most common implementation, web developers do have the option to use alternative file types and custom filenames by modifying HTML tags.

Here are the most widely used formats for site icons:

• ICO – The most compatible across all browsers
• PNG – Great for transparency, widely supported
• SVG – Scalable, but with limited support in older browsers

Despite these alternatives, using the conventional favicon.ico file name and format remains the most reliable approach for ensuring consistent visibility across all platforms and browser versions.

Does ICO have another meaning? (Initial Coin Offering)

Yes, in the context of cryptocurrency and blockchain technology, ICO stands for Initial Coin Offering. This refers to a fundraising method where new cryptocurrency projects sell their underlying tokens to early supporters. When people search for information about what an ICO is in this context, they are referring to this completely separate concept from image files or browser icons. It's important to recognize this distinction when encountering the term in different technical contexts.

Conclusion

Understanding what a favicon.ico file is helps explain how browsers handle and display website icons. Despite new formats like SVG or PNG gaining popularity, the traditional file still provides unmatched compatibility and ease of use. For web developers prioritizing broad support and professional presentation, the ICO format remains a practical and reliable choice for favicon implementation.