in org-mode, how to make code blocks folded by default?

Question

In Emacs org-mode, how would I instruct org-mode to make HTML code blocks folded by default? So that when I open an org file they are folded?

Answer 1

org-mode provides this feature out of the box. You can set it globally by customizing the variable org-hide-block-startup. To set this for a single file, add

#+STARTUP: hideblocks

To the header. Here's the relevant section of the manual