There are quite a few questions on this topic, but I did not find anything that I liked.
I decided to update my one-page portfolio and make it multi-page (github pages). For convenience, I would like to embed repeating 3 files head, header, footer. What can be used to do this so that it has minimal impact on performance.
Thank!
This article offers many ways to do what you're trying to do, but I think the easiest one is:
<body>
<iframe src="./header.html"></iframe>
Content.
<iframe src="./footer.html"></iframe>
</body>
and the one it suggests will minimally impact performance is:
<body>
<?php include "./header.html" ?>
Content
<?php include "./footer.html" ?>
</body>