Structured Page Fragments by YouTube (2017)

What&#x27;s the reason for posting this? It&#x27;s been posted before (<a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10667783" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10667783</a>) and the repo seems to be dead since beginning 2017 (4 open PR&#x27;s from 2017).<p>It also looks like it doesn&#x27;t fit the current web-meta anymore :)

Unpoly [1] lets you achieve the same effect without having to wrap your content in a JSON transport envelope. There are no two cases for static and dynamic navigation. The HTML you already have is used for transport, fragments are targeted with CSS selectors.<p>[1]: <a href="https:&#x2F;&#x2F;unpoly.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;unpoly.com&#x2F;</a>

&gt; A [...] framework for fast navigation and page updates<p>Not sure what the criteria for &quot;fast&quot; is, but on my 12&#x27; MacBook with Safari, it&#x27;s consistently faster (and less glitchy) to just load a new Youtube page than to let this &quot;fast&quot; navigation do it. Using Youtube is actually painful because of this.

Isn&#x27;t this whole idea flawed? How is dynamic JS content update easier for browser than static HTML5 content? Overall amount of CPU time and RAM used will be larger so if anything it&#x27;s not faster or lighter. Also turning off JS for site using this lib makes it unusable.

I have a strong feeling this isn’t actually faster in most cases, but I’ll try and see. Maybe it’s the fact that your main content can in theory load faster than the page parts that are not as important.

How does this compare to PJAX : <a href="https:&#x2F;&#x2F;github.com&#x2F;defunkt&#x2F;jquery-pjax" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;defunkt&#x2F;jquery-pjax</a> ?

Even YouTube isn&#x27;t using it anymore