> Is this happening because org-info.js is no longer being maintained?  Another solution I saw was Daniel Clemente's tool, though I am at a total loss for what to specify in the org file to incorporate his esquemadorg.js script. I appreciate any help that could let me export large org files to HTML while having the headers be collapsible.

Sorry for the very late answer. I just added some instructions about what to add to the .org file.
But it looks like the best way is to adapt any existing tool to your needs.
Collapsing/expanding headers isn't very hard — the harder parts are things like how to make links keep working (e.g. links to sections which are now collapsed should auto-open it).  
 

On Wed, Nov 6, 2019 at 12:04 AM Kris Brown <sirkris.brown@gmail.com> wrote:
Hi, I am trying to have basic folding functionality for my org file that has been exported to HTML. I am using Emacs 26.2 (9.0) and Org 9.1.9 on a Mac.

This seems to be a built-in feature: JavaScript supported display of web pages. I downloaded my own copy of org-info.js. However, I cannot see any difference when I use the #+INFOJS_OPT commands or not (org with, org without, html with, html without). I would expect to see collapsible headers and no TOC displayed when I use those commands.

There is a difference in the generated HTML files (an extra CDATA region with a bunch of statements like: org_html_manager.set("VIEW", "info");) but nothing different visually.

Is this happening because org-info.js is no longer being maintained?  Another solution I saw was Daniel Clemente's tool, though I am at a total loss for what to specify in the org file to incorporate his esquemadorg.js script. I appreciate any help that could let me export large org files to HTML while having the headers be collapsible.