JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://jquery/jquery/dist/jquery.js"></script>
<div class="test alpha">
    Tests
</div>
<div class="test alpha" id="two">
    Tests
</div>
<div class="test gradient">
    Tests
</div>
<div class="test alpha gradient">
    Tests
</div>
<div class="test">
    Tests (this is the only one that should remove filter)
</div>

CSS

.alpha {
    filter: Alpha(opacity=25);
    -ms-filter: Alpha(opacity=25);
}
.gradient {
    filter: progid:DXImageTransform.Microsoft.gradient(startColorStr='#abcdef', EndColorStr='#ffffff');
    -ms-filter: progid:DXImageTransform.Microsoft.gradient(startColorStr='#abcdef', EndColorStr='#ffffff');
}
.test {
    height: 100px;
    background: #abcdef;
    font-size: 13px;
}

JavaScript

function txt(text) {
    $("body").append($("<pre>").text('"' + text + '"'));
}

$(".test").animate({
    opacity: 0
}, 1000).animate({
    opacity: 1
}, 1000, function() {
    txt(this.currentStyle.filter);
    txt(this.style.cssText);
});