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How to change a favicon's file format for old browsers

Convert a PNG or other image to ICO for older browser support, then add the right favicon link and check its dimensions, location, and cache.

Emily ParkerTools and utilities Tools 4 min read

Your website icon looks right in a recent browser, but an older browser shows a blank page icon or no icon at all. The image may be in a format that browser does not support, or the browser may be looking for a different file.

Converting the image to ICO is a common compatibility step. Use the Image Converter to make an ICO file in your browser, then check the file dimensions and the link used by your website.

Convert the favicon to ICO

  1. Open the Image Converter and select the image you currently use for the favicon. A square PNG is a useful starting point because it can preserve transparent areas.
  2. Choose ICO as the output format and convert the image. The converter supports ICO alongside formats such as PNG, JPG, GIF, BMP, WEBP, and TIFF.
  3. Save the converted file as favicon.ico. Check the downloaded file and note its dimensions before putting it on your website.
  4. Place favicon.ico in your website's root folder, or put it in another folder and use that location in the page's icon link.
  5. Add or update the icon link inside the page's <head>. For a file in the root folder, use <link rel="icon" href="/favicon.ico" type="image/x-icon">.

If you maintain separate page templates, make sure the link is included in the template used by the pages you want to test. A file that exists on the server will not appear if the page points to a different name or path.

Choose a format for your visitors

ICO for older browser compatibility

ICO is a practical choice when you need to support older browsers or software that expects a traditional favicon. Some browsers automatically look for /favicon.ico at the website root, even if the page does not include an icon link. Providing that file can help with this fallback, but it does not guarantee that every older browser or device will display it.

PNG for modern browsers

PNG is widely supported by current browsers and keeps transparent edges clean. If your site already uses a PNG favicon and it appears correctly for your visitors, you may not need to replace it. You can provide both PNG and ICO files, with separate icon links, to serve newer browsers and maintain a familiar fallback.

Check dimensions as well as the extension

Changing a file's format does not necessarily change its dimensions or create a set of icon sizes. An ICO file can contain several sizes, but a simple format conversion may contain only the dimensions of the source image. Check the converted file, and make a suitably sized square source image before converting if the result is too small, too large, or distorted.

A very small source image can look jagged when a browser displays it larger. A wide or tall source image may be squeezed or cropped by some software. Keep the artwork centered in a square canvas, with a little space around its edges, and inspect it at the small size where a favicon normally appears.

If the old browser still shows no icon

  1. Check the file path. Open the icon URL directly in a browser, such as https://example.com/favicon.ico, replacing the domain with your own. If the file does not open, check that it was uploaded to the folder named in the link.
  2. Check the filename and capitalization. Use the same spelling in the file and in the link. Some web servers treat Favicon.ico and favicon.ico as different names.
  3. Check that the file is really ICO. Renaming a PNG file to end in .ico does not convert it. Convert the source image, then confirm the downloaded output has the ICO format.
  4. Check the page source. Make sure the icon link appears inside the page's <head>, and that its href matches the actual file location. If you provide more than one icon link, verify that the ICO link is not pointing to a missing file.
  5. Refresh the browser's saved icon. Browsers often keep favicons in a separate cache and may continue showing an old icon after the page changes. Open the site in a private window or another browser to check whether the updated file is available, then clear the affected browser's cached site data if needed.
  6. Check the server response. If the icon URL opens in a modern browser but not on the older one, check that the server returns the ICO file rather than an error page, and that your site or hosting setup is not redirecting the request to a different address.

Why a format change may not be enough

Favicon support depends on the browser version, operating system, and where the icon is displayed. A browser tab, bookmark, home screen shortcut, and desktop shortcut may not all use the same icon lookup rules. Test the actual older browser and the way people reach your site, rather than relying only on a modern browser preview.

Also keep the original image. If you later need a sharper icon or a different size, you can create a new source image and convert it again. The Image Converter runs in your browser, and the files you open stay on your device.

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