As of Jan 28 this year (2026) Nekoweb News announced Server Side Includes (SSI) support! This is something that Neocities (the host I use) does not yet offer.
If you’re unfamiliar, SSI allow webmasters to easily insert an HTML snippet into many other pages, without JavaScript or iframes, which is very useful for things like menus/nav bars, headers, and footers that you want to be the same on multiple pages.
I’m not 100% sure how to use them either, but I think I’ll try!! And yea, on Neocities I’ve been using JS to inject my side menu links into my rainbow pages. Its not a terrible solution, though I know people around these parts are more likely to block JS. I think I did try using an iframe for my menu, but there was something about styling it that I got frustrated with (don’t remember exactly what).
I just tried it out, and its really easy!! I put my repetitive html junk into a standalone file I called “sidebar.html” (doctype and stuff is not needed)
And on my pages in the HTML where I want to put the sidebar I put <!‐‐# include file=“sidebar.html” ‐‐>
And thats it!
Overall note for this thread: it works for free accounts! The 7$ subscription tier for Nekoweb mentions SSIs in one of its perks (“Create dynamic blogs, galleries and more with SSI”), so I thought maybe you would need that tier to use SSI to begin with, but it seems that is for more advanced stuff, the simple HTML include worked just fine on my free account ^^