There is no built-in setting for the width. You can use a custom style rule to modify the autocomplete drop-down. Custom style rules can be applied to Firefox's user interface using either:

• the Stylish extension: https://addons.mozilla.org/firefox/addon/stylish/
• a userChrome.css file: http://kb.mozillazine.org/UserChrome.css

One option would be to use my user style here: https://userstyles.org/styles/122394/url-bar-tweaks-remove-visit-search-limit-width -- Option (1A) lets you limit the width of the new style drop down (title and url on the same line).

Alternately, you could paste this rule to a blank new Stylish style or your userChrome.css file, and then edit the width as desired:

#PopupAutoCompleteRichResult {
  max-width: 1000px !important;
}

Note: 1000 pixels is adjusted by your Windows Text Size percentage, often 125%, so on screen it would be 1250 pixels in that case.

Edit: Added screen shot of the option.

jscher2000 said

There is no built-in setting for the width. You can use a custom style rule to modify the autocomplete drop-down. Custom style rules can be applied to Firefox's user interface using either:

• the Stylish extension: https://addons.mozilla.org/firefox/addon/stylish/
• a userChrome.css file: http://kb.mozillazine.org/UserChrome.css

One option would be to use my user style here: https://userstyles.org/styles/122394/url-bar-tweaks-remove-visit-search-limit-width -- Option (1A) lets you limit the width of the new style drop down (title and url on the same line). Alternately, you could paste this rule to a blank new Stylish style or your userChrome.css file, and then edit the width as desired:

#PopupAutoCompleteRichResult {
  max-width: 1000px !important;
}

Note: 1000 pixels is adjusted by your Windows Text Size percentage, often 125%, so on screen it would be 1250 pixels in that case.

Edit: Added screen shot of the option.

I'm sorry but the Stylish extension and that other thing, the userChrome.css file looks too complicated for me, at least. I don't want to download anything either. I just want the drop down menu for suggestions to go back to the way it was before the latest Firefox update. Does anyone have a simple way to do this, please? Like step by step instructions? I can't figure out how to do this and like I mentioned I don't want to use any more add-ons. I don't understand why the autocomplete drop down changed anyway. It was great the way it was before, now it's extremely annoying.

I finally got some help at the Mozillazine forums. Someone there suggested I use CTR (Classic Theme Restorer) and then helped me with fixing the problem with the too-wide autocorrect drop down window.

For convenience, here a link to the other thread: http://forums.mozillazine.org/viewtopic.php?f=38&t=3020177