Use the animation-direction property to run animation in reverse direction. The property is used with the reverse animation value to achieve this.
Example
<!DOCTYPE html> <html> <head> <style> div { width: 150px; height: 200px; background-color: yellow; animation-name: myanim; animation-duration: 2s; animation-direction: reverse; } @keyframes myanim { from { background-color: green; } to { background-color: blue; } } </style> </head> <body> <div></div> </body> </html>