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Invalid input

Written byPhuoc Nguyen
30 Sep, 2022
The animation is often used to indicate an invalid input. It shakes the input for a while.
Press the Enter key to see the effect
The shaking animation moves the element to the left and right sides. It can be done by using the `translateX` function:
@keyframes shake {
to {
transform: translateX(0);

80% {
transform: translateX(-1rem);

60% {
transform: translateX(1rem);
To use the animation, we can add a simple `animation` style:
.input--invalid {
animation: shake 1s;
outline-color: #ef4444;
Let's assume that `inputEle` represents the input element. You can add the invalid CSS class created above anytime to indicate the input is invalid:

Remove the animation

If you want to remove the invalid state from the element when the animation completes, you can handle the `animationend` event:
inputEle.addEventListener('animationend', (e) => {
if (e.animationName === 'shake') {
Inside the event handler, you can use the `animationName` property to check which animation is completed. It's very useful in the case the element runs more than one animation at the same time.
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Phước Nguyễn