Similar but not the same as this question https://support.mozilla.org/en-US/questions/1283932 This doesn't happen all the time, but think of a word that might be a domain name that you haven't visited lately. Maybe "cisco" or "atlassian". You might want to type that in the address bar on Firefox Mobile to search for it (in my case my search engine is DuckDuckGo.) However sometimes instead of searching, the browser decides "oh, you wanted to go to cisco.com ?" and starts navigating there. Then of course there's a bunch of frustrated clicking to stop the navigation and type the same word minus the .com despite now being autocompleted as .com. My guess as to what's happening is that some intrepid programmer at Firefox or DuckDuckGo thought "sometimes people type facebook wanting to go directly to facebook.com, so I'll check DNS or a search engine first and if there's a sensible result I'll just go straight there instead of searching" however the behavior only happens rarely and for nonsensical words. I most often experience this issue when wanting the dictionary definition to something like "doofus" and then randomly end up on something like doofus.com (pretend that's a real website; it's always a real random website that just coincidentally has a word as a domain). Or maybe try the word "fool" which seems to autocomplete to "fool.com" for me despite never having been there as I'm not an investor. Is there anything in the Firefox codebase that would decide to autocomplete something as a URL even when it's typed in as a single word with no spaces or punctuation?