Use the transition-timing-function property to set the speed curve of the transition effect. The values you can set are: ease, ease-in, ease-out, linear, etc.
Example
You can try to run the following code to set the speed curve of the transition effect with CSS −
<!DOCTYPE html> <html> <head> <style> div { width: 100px; height: 100px; background: red; transition: width 4s; } #effect1 { transition-timing-function: linear; } #effect2 { transition-timing-function: ease-in; } div:hover { width: 250px; } </style> </head> <body> <h1>Transition Effect</h1> <p>Hover over the div elements and see the transition effect and the speed:</p> <div id = "effect1">linear effect</div><br> <div id = "effect2">ease-in effect</div><br> </body> </html>