Encountered a problem: An error occurred during rendering of a custom WOFF font in the web application

Question

I'm currently developing a web application and trying to implement a custom font for specific elements using the @font-face rule in CSS. I've followed the standard process of defining a font and applying it to a specific element, but I'm having trouble rendering the font correctly.

Here is the relevant code I used:

@font-face {
    font-family: swiper-icons;
    font-style: normal;
    font-weight: 400;
    src: url('data:application/font-woff;charset=utf-8;base64,d09GRgABAAAAAZgABAAAAAD...'); /* The rest of the base64 encoded font data */
}

.my-custom-font {
    font-family: "swiper-icons", sans-serif;
}

I have decoded the base64 string and saved the font file with a .woff extension. However, when I apply the my-custom-font class to an element, the font doesn't seem to render as expected. I tried previewing the font using an online font rendering tool (https://fontdrop.info) but that didn't work either.

Things I checked and tried:

• I made sure the entire base64 string was decoded correctly.
• I verified that the font file was saved in a valid format.
• I used the correct font family name ("swiper-icons") in the CSS.
• I checked the browser's console and there are no error messages related to font loading or rendering.

Is there something I may have missed or done wrong? Are there additional steps needed to ensure the fonts render correctly? Are there possible compatibility issues between certain font formats or online rendering tools? Thank you very much for any guidance on how to resolve this font rendering issue.

Answer 1

Here are some of my common troubleshooting steps:

1. Browser support: Make sure the browser supports the WOFF format. If possible, use WOFF2 for better performance.

2. Base64 decoding: Check the Base64 decoding carefully to make sure no errors are introduced.

3. Font Validity: Test the font file on a tool such as Font Validator or W3C’s validator.

4. CSS Check: Make sure no other styles override your custom font. To test, try using a more specific selector to apply the font to the element.

5. Font Name: Verify that the font's internal name matches your CSS declaration.

6. Local Testing: Temporarily use a locally hosted font file instead of Base64 to see if the problem is encoding-related.

   @font-face {
       font-family: swiper-icons;
       src: url('path-to-your-font.woff') format('woff');
   }
   

7. Different Browsers: Test on a variety of browsers to see if the problem is specific to a certain browser.

8. Font Properties: Check whether the font has special properties or settings that need to be activated through CSS.

9. CORS: If hosted externally (non-Base64), make sure the CORS policy does not prevent the font from loading.

10. Backup font: Use the fallback font as a backup in the font-family attribute.

11. Online Tool Issues: Please keep in mind that some online tools may have their own compatibility issues.