Replace a textNode with HTML text in Javascript?

You'll need to replace the textNode with an HTML element, like a span, and then set your linkified-text as that element's innerHTML.

var replacementNode = document.createElement('span');
replacementNode.innerHTML = linkify(n.textContent);
n.parentNode.insertBefore(replacementNode, n);
n.parentNode.removeChild(n);

Additionally to previous answer I propose more short way (based on jQuery):

$(n).replaceWith('Some text with <b>html</b> support');

where n - is textNode.

Or the native version

var txt = document.createElement("span");
txt.innerHTML = "Some text with <b>html</b> support";
node.replaceWith(txt);

where node is the textNode