Forcing Firefox to load pages from cache
A quick tip on how to force Firefox to save and load
pages to and from cache, even over secure connections.
Published on 2020-04-10
In the fifteen or so years I’ve been using the internet, the connection speed has gotten faster and faster. In the mid-2000s, when using the family computer to look up cheat codes for video games, it was on a dial-up connection, excruciatingly slow by today’s standards and further limited by my parents’ telephone calls – and I’ll never forget when I realized that Internet Explorer could save a web page to the hard drive. I could simply save all the pages with the cheat codes I wanted and look them up instantly at any time, regardless of whether the telephone line was free.
Caching is like that, but your browser does it for you.
Unfortunately, in the last couple of years, I’ve started
to notice that Firefox doesn’t seem to load pages from
cache as much as it used to. And even though my connection
speed is faster than ever, it is very noticable. The
internet still isn’t instant, and furthermore, sites are
becoming more and more heavyweight.
First, I thought it might be a setting in Firefox that
has been changed. Perhaps Mozilla figured that modern
connection speeds are high enough to make caching
unnecessary. But, after some research, I found that the
reason is that more and more sites have been migrating to
HTTPS (and regrettably disallowing HTTP access) – which
wouldn’t be a problem if Firefox cached pages served over
HTTPS, but it turns out that Firefox refuses to do so,
unless the page is explicitly served with a Cache-Control:
public header. And because there is no preference
that changes this, the only solution is to manually change
the headers of all pages that Firefox loads.
The simplest way is to use an extension. Here are my suggestions:
I’ll describe the setup that has worked for me. There are probably other combinations that work, but I haven’t tried all of them.
After setting this up, make sure that the browser.cache.
Also, I’ve seen some people suggest disabling disk caching and relying completely on in-memory caching. If you have the memory for it (I unfortunately don’t), this is a very good idea. You could do something along the following lines:
The reason you’d want to do this is security. If you visit pages that serve private, sensitive content, like your online bank, you might not want those pages saved to the hard disk.