How to change the mouse cursor using an SVG image.

To change the default mouse cursor using an external image, you need to:

1. Create an SVG image;
2. Convert it to data URI so that you can use it in CSS.

To convert the SVG to Data URI, you can use tools like the URL encoder.

In CSS:

.custom-cursor {
  cursor: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='64' height='64' viewBox='0 0 64 64'%3E%3Ctitle%3Ecursor-link%3C/title%3E%3Cg%3E%3Ccircle cx='32' cy='32' r='30' opacity='.8'%3E%3C/circle%3E%3Cpath d='M30.828 28.172l-.585-.586a2 2 0 0 1 0-2.828l6.171-6.171a2 2 0 0 1 2.828 0l6.171 6.171a2 2 0 0 1 0 2.828l-6.171 6.171a2 2 0 0 1-2.828 0l-.586-.585' fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='2'%3E%3C/path%3E%3Cpath d='M33.172 35.828l.585.586a2 2 0 0 1 0 2.828l-6.171 6.171a2 2 0 0 1-2.828 0l-6.171-6.171a2 2 0 0 1 0-2.828l6.171-6.171a2 2 0 0 1 2.828 0l.586.585' fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='2'%3E%3C/path%3E%3Cpath fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M27 37l10-10'%3E%3C/path%3E%3C/g%3E%3C/svg%3E") 32 32, pointer;
}

The two coordinates that follow the SVG code determine the custom cursor's origin on the "x" and "y" axis. In our example, because the icon is 64x64 pixels, the center is "32 32".

The "pointer" value that follows the coordinates is the cursor fallback.

At the moment, some browsers seem to convert the SVG image to a low-resolution PNG image. To fix this issue, create two additional PNG versions of the custom cursor (one should be 2x the cursor size - 128px in our example) and convert them to Data URI.

Then, in CSS:

.custom-cursor {
  cursor: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='64' height='64' viewBox='0 0 64 64'%3E%3Ctitle%3Ecursor-link%3C/title%3E%3Cg%3E%3Ccircle cx='32' cy='32' r='30' opacity='.8'%3E%3C/circle%3E%3Cpath d='M30.828 28.172l-.585-.586a2 2 0 0 1 0-2.828l6.171-6.171a2 2 0 0 1 2.828 0l6.171 6.171a2 2 0 0 1 0 2.828l-6.171 6.171a2 2 0 0 1-2.828 0l-.586-.585' fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='2'%3E%3C/path%3E%3Cpath d='M33.172 35.828l.585.586a2 2 0 0 1 0 2.828l-6.171 6.171a2 2 0 0 1-2.828 0l-6.171-6.171a2 2 0 0 1 0-2.828l6.171-6.171a2 2 0 0 1 2.828 0l.586.585' fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='2'%3E%3C/path%3E%3Cpath fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M27 37l10-10'%3E%3C/path%3E%3C/g%3E%3C/svg%3E") 32 32, pointer;

  /* 👇 PNG fallback */
  cursor: -webkit-image-set(url("data:image/png;base64,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") 1x, url("data:image/png;base64,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") 2x) 32 32, pointer;
}

Here's a live demo: