JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" onkeyup="checkInput(this.value)" /><span id="clearBtn1" class="clearBtn">X</span>

CSS

.clearBtn {
    position: relative;
    left: 0;
    transition: left 0.3s;
    display: none;
}
.show {
    display: inline;
}

JavaScript

function checkInput(text) {

    if (text != ""){
        $("#clearBtn1").addClass("show");
    } else {
        $("#clearBtn1").removeClass("show");
    }

}