.noselect {
-webkit-touch-callout: none; /* iOS Safari */
-webkit-user-select: none; /* Safari */
-khtml-user-select: none; /* Konqueror HTML */
-moz-user-select: none; /* Old versions of Firefox */
-ms-user-select: none; /* Internet Explorer/Edge */
user-select: none; /* Non-prefixed version, currently
supported by Chrome, Edge, Opera and Firefox */
}
<p>
Selectable text.
</p>
<p class="noselect">
Unselectable text.
</p>