It has been great until recently, when I started experiencing severe lagging in Firefox and discovered that this extension is a memory hog.

Here's my `top` with HTTPS Everywhere enabled:

PID PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
9036 20 0 14.6g 218564 107332 S 0.0 1.3 0:25.73 WebExtensions

...and when the add-on is disabled:

PID PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
9036 20 0 8970992 199000 107204 S 0.3 1.2 0:26.00 WebExtensions

I have no idea why it needs to commit 14Gb of virtual memory, but that does not sound reasonable at all. I'll keep it switched off for now to see if the overall performance improves.

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.2 LTS
Release: 20.04
Codename: focal

$ uname -a
Linux xxxxx 5.4.0-66-generic #74-Ubuntu SMP Wed Jan 27 22:54:38 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

$ firefox --version
Mozilla Firefox 86.0

HTTPS Everywhere Version 2021.1.27

This was a great add-on when first created, but lack of innovation has made it fall behind over the years. I quit using it a while ago in favor of Smart HTTPS, which does the same thing but provides two very important extra features: it automatically retries without HTTPS if the page fails to load, and it whitelists the site so it won't try again next time. This allows you to have the safety of using HTTPS when possible, but also prevents breakage, which can range from annoying to problematic (in the case of a basic user). It's a shame this add-on never provided similar functionality, as I'd prefer to use it over the other due to being provided by the EFF vs some random developer.

In Google Playstore, it prevent me edit my review.
This trouble doesn't appear when I use Google Chrome, Microsoft Edge Chromium.

This extension is no longer really necessary. 95% of the internet now uses HTTPS, and whether it's entered in the address bar or not, one is always forwarded to it.

The change occurred naturally at first, but was really spurred on by Google no longer prioritizing sites that do not support HTTPS.

Don't get me wrong, this extension was once wonderful and one of the first things I installed. However, it no longer serves any useful role.

I using this extension and this is really good. But some sites don't support https. Please, when we click "don't use on this site" redirect location to http site. Because we need make it manual yet. Or you can add a option for this.

Edit: I did delete extension. Not good for end-users. Didn't answer..

Do I really need it in Firefox after so many built in privacy in Firefox!

Works more often than it doesn't but unfortunately seems to dislike some sites and even after going to the site despite it being unable to load https, this addon will force it to load into a 404 error. This can only be fixed by turning it off in the options page of firefox. Incredibly irritating when it's a site I use often.