If you type "what is the time" on google and you are using a 3G smartphone, it shows the time and your location as an area about 30 square miles big in my case. If you do the same with the Opera Mini browser on the same smartphone it shows your location as a 4 square mile area. Neither browser is allowed access to the GPS so this is entirely IP based. So our locations are monitored and available to Google Inc.

Typing "what is the time" on a laptop with ADSL internet access does not return such precision. But if you connect the smartphone to the same wifi, the smartphone shows the same 4 square mile area that is showed with 3G access.

What is the most precise way to tell an IP's location with a linux laptop alone? Why is Opera Mini so much more precise even with ADSL access?

I just tried with my main computer (hardwired ethernet to adsl router to land line) and was told that I am in London N13. Which is not true. So it seems they can't do much with just the IP address.

I too can be located in London - VPNs are a wonderful thing.
IPs give a general location, mobile SIMs locate to a tower, wifi routers and/or bluetooth locate much more specifically. I turn it all off. Companies here boast of "heat maps" from phones using MAC address at things like concerts so they can determine what are popular booths for patrons to visit. Scary shit, and completely without your say-so.

I have a Mac and I don't really care how it is known. ("Location services" is how)
I suspect your upstream provider's gateway IP setting may be telling on you.

nameservers are a semi-fixed asset (rDNS...)

I utilize
1.0.0.1
9.9.9.9

Just sayin'
John out.

this is my experience too.
no vpn.
no google accounts.
no cookies, no javascript or anything else.
just the IP - they get the general vicinity, about 200km in all directions, not more.

and on my phone, of course the same as above, plus no gps.

But why is the Nokia Mini browser more precise than the default browser?

From the W3C Geolocation wiki page
I suspect that either you have given permission or that the browser is doing it regardless of your phone settings. No expert on the geolocation API but as posted the API will find the best location and for the desktop and hopefully from a mobile device if no permissions are given that of the ISPs. It it also possible that your router's mac and location were recorded by any other phone with GPS enabled and by Google's street view cameras.

https://www.w3schools.com/html/html5_geolocation.asp

Maybe there is a way for the smartphone to connect to the internet through the usb cable. If so, it would be interesting to see what happens if the smartphone is put in plenty of aluminum foil and google time is then checked.

^ ok, i smile indulgently.

back to post #1. have you repeated the experiment often enough (and in many different locations, not just your home town but further away) to be able to deduce that opera mini browser always gets it better?
or maybe it's just lying to you?
i also heard that opera browsers cache half of the internet for you, thus making it "Turbo". could have some impact.
in the end, there's many factors that could have some impact.

"Location services" on Android phones includes much more than the built-in GPS, and there's always stories that some software manages to get more informatioin than the user agreed to...

i always have my gps switched off. I switch it on about once a year (when I'm lost in the forest). It takes about 5 minutes before it finds my location reliably.
with that in mind, i would think that the OFF switch does indeed switch it off, and it is not possible for apps to use it regardless. but i might be wrong.

PS:
the Librem 5 is going to have hardware kill switches for these things, there you could make some more definite experiments.

With a modern cell phone I think someone could locate you to a much closer range then 200km. I believe they could at least tell what cell tower you are connected to. Maybe even triangulate using 2 or more towers depending upon where you are. For triangulate, I am only speculating.

Stop speculating: you can do this and the accuracy can be somewhere around 50 metres. Probably better in conurbations and worse out in the open country due to the density of cell towers. This was useful back when GPS wasn't a standard feature that you could expect to be present on nearly all (smart)-phones so if you wanted to sanity check the location of someone making an emergency call (which probably wasn't going to originate from an indoors location where GPS is flaky at best).

When stores do this they want to know which display or department you're hovering by and for how long. For this they need a few metres of accuracy and they can do this from bluetooth. What they then want to do is to track an individual phone and they have been doing this by looking at battery charge level which isn't totally reliable but is totally sneaky. I think that there has been a move to stop you reading battery level with later APIs to make this difficult but I didn't follow this debate fully through to the end and don't know which phones/OSs this still works with.

Incidentally I've been watching with interest some of the 'meet single women in xxxxxxx area' adverts that pop up from time to time. For me this doesn't seem to give them accurate info but a value that is about 50 miles out. On the other hand they seem to have gender-located me quite accurately until quite recently. Maybe they were just using the default...