Custom Cursor

A shape or label trails the pointer with a spring or eased delay.

Add a "Cursor Follower" (also called a following pointer or smooth cursor) to [where].
A small round marker should trail the pointer with a soft, eased delay and glide to a stop right where the pointer rests, without bouncing.
Keep the real pointer visible, never let the marker block clicks, and leave it out on touch devices.

A circle cursor inverts the colors beneath it using mix-blend-mode difference.

Add a "Blend-Mode Cursor" (also called a difference cursor or inverting cursor) to [where].
Replace the pointer with a solid circle that sits directly under it with no lag and inverts the colors of the text and shapes it passes over.
Keep the blending contained to that area so it does not mix with the rest of the page, make sure it still inverts clearly in dark mode, and keep the normal cursor on touch devices.

A fading string of shapes is left behind the pointer as it moves.

Add a "Cursor Trail" effect (also called a mouse trail) to [where].
As the pointer moves, it should leave a short string of small dots behind it that each shrink and fade away quickly, so the trail stays short and smoothly traces the path.
Only draw the trail while the pointer is moving, never let it block clicks, and leave it out on touch devices and for users who prefer reduced motion.

The text caret grows or shrinks to match the size of the character it sits beside.

Add an "Adaptive Caret" effect (also called adaptive caret size) to [where].
The text caret should move in front of the character nearest the pointer and quickly stretch or shrink to match that character's height, with a smooth, snappy resize and no bounce.
Keep the text itself from shifting, and let the caret follow keyboard movement the same way it follows the pointer.

The element is pulled toward the pointer as it comes close, then snaps back when it leaves.

Add a "Magnetic Button" effect (also called a magnetic target or magnetic hover) to [where].
As the pointer comes close, the button should be pulled a little toward it with its label moving slightly further, and when the pointer leaves it should spring back to its place with a small bounce.
Keep the surrounding layout from shifting, and turn the pull off on touch devices and for users who prefer reduced motion.

A field of small lines rotates to point at the pointer, like iron filings around a magnet.

Add a "Magnetic Filings" effect to [where].
A grid of short lines should each turn to point straight at the pointer right away, like iron filings around a magnet, and all face the center when there is no pointer.
Keep it a decorative background that never blocks clicks, and leave the lines still for users who prefer reduced motion.