How to enable it for all websites?

Very simple but works. The only "Disable javascript" addon that I have tried that actually renders all noscript tags properly.

Life saver extension. This very nicely tames down certain websites. It's analogous to the enable-javascript button in Safari security settings. Only this is a convenient button right there you can toggle on/off without bringing up a settings menu. Some people mentioned the button isn't there. I default to a normally blank page. The button shows up once you go to a webpage. This (and Ghostery) are critical add-ons to taming down webpages in Firefox!

Quick and easy to disable/enable JS.

A bit dissapointed, as the author stated he picked up "Javascript Control by Erwan Ameil" to change it's default behaviour (disabled). But he ended up leaving it disabled by default. So what's the point? I installed this expecting he would keep his word on his comment:
"by meetDeveloper, 6 years ago
I really liked this add-on apart from its default policy, so I forked the Code and edited to change the default policy, and made a new extension https://addons.mozilla.org/en-US/firefox/addon/quick-js-switcher/ , feel free to install that. "

Just great, much better than the one written by Erwan Ameil. 99.9% of sites I visit, use Java, it is a real pain having to turn it on all the time, a default to one is awesome. Keep up the good work.

It is a very convenient addon that you can set the default status of script being "on" or "off".

is it possible disabled js by default

Android安装成功，也可以切换JS，但是地址栏图标在开和关时没有颜色变化。是否考虑更好地兼容Android？