How do I use the 'logo' option in shields.io badges?

You can use logo names from Simple Icons without base64 conversion.

https://img.shields.io/static/v1?message=css3&logo=css3&labelColor=5c5c5c&color=1182c3&logoColor=white&label=%20&style=plastic

Here is a 3-step guide to use a logo, e.g. the GitHub logo, in a shield/badge.

1. Encode the image in Base64.

   From Wikipedia

   Base64 is a group of similar binary-to-text encoding schemes that represent binary data in an ASCII string format by translating it into a radix-64 representation. The term Base64 originates from a specific MIME content transfer encoding.

   Download the image and use one of the many online tools, e.g. http://b64.io/, to encode it.
   The results is a string starting with data:image/png;base64, and followed by a very long string of characters.

2. Encode the Base64 string in percent-encoding.

   From Wikipedia

   Percent-encoding, also known as URL encoding, is a mechanism for encoding information in a Uniform Resource Identifier (URI) under certain circumstances. Although it is known as URL encoding it is, in fact, used more generally within the main Uniform Resource Identifier (URI) set, which includes both Uniform Resource Locator (URL) and Uniform Resource Name (URN).

   Take the very long Base64 string and use (again) one of the many online tools, e.g. http://meyerweb.com/eric/tools/dencoder/, to encode the string.
   Some characters will be replaced with % followed by two hexadecimal digits. For example, / is replaced with %2F.

3. Finally, append the encoded string to your shield URL after ?logo=. As an example: https://img.shields.io/badge/gadget-Raspberry%20Pi-pink.svg?logo=data%3Aimage%2Fsvg%2Bxml%3Bbase64%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%3D corresponds to . You can try using this one.

TIP: sometimes the encoded string, of either step 2 or 3, may be too long to be used. You should then try to reduce the size (total pixels) of the image and try again.

You can use something like this

![Raspberry Pi](https://img.shields.io/badge/raspberrypi-Code?style=for-the-badge&logo=raspberrypi&logoColor=black&color=F1C232

be aware of the following parameters

• logoColor controls the color of the logo.
• color Controls the color of the backgound

you need to base64 the logo you can use http://b64.io/ to convert your png to base64 code the link need to be entity escaped your image was too large for the uri, you can scale it to 14px of height.