Can websites recognize the same device despite a different IP?

I have logged into my own Wi-Fi with my laptop on a website that does not support "multi-accounting". When I was with a friend, he also logged in there via my laptop (logically the laptop was then in his Wi-Fi network). Now my question is, can a website recognize that it is the same device?

Really don't realize no.

But it could possibly access hardware data and try to draw conclusions from "who" you are.

Websites do not recognize you based on your IP but rather based on cookies that are stored

But there are also sites that save the IP addresses, but do not necessarily associate them with a device or people or anything else

It recognizes which OS (e.g. Windows 10) you are using, which OS version (e.g. Version 10.0.19042 Build 19042) you are on and which browser (e.g. Chromium) you are using. It always depends on how the website reacts. Pay attention to whether there's 1 account per household or per device / person

He used a different browser than I use by default. Accordingly, the cookies shouldn't have "given away" anything, right?

In most cases, the answer is simple and simple: Yes, of course.

And don't listen to people who suggest TOR, VPN, proxies or anything like that. They mask the IP address to a certain extent - but they do not protect against tracking.

You have to bring up guns like a blackhole server.
With a https://www.youtube.com/...epp1nyF1US you can retrofit this cheaply, effectively and easily in the home network.

There are methods called browser fingerprinting. An attempt is made to recognize the browser based on the installed add-ons, but also the operating system, time zone, standard language or hardware data. According to Mozilla, the process is 99% secure, you can read more about it https://www.experte.de/it-sicherheit/browser-fingerprint. https://amiunique.org/ you can see how unique your browser is (the more unique the worse). But there are methods to protect yourself against it. There are e.g. Add-ons that falsify data such as the browser version.

Okay I see. I just use a standard off-the-shelf laptop. So the chances of the hardware being the same as some of the others are high, right?

I didn't even know that there was such a thing. Very interesting and good to know.

Correctly.
Of course, it is assumed that the website does not save any data - if you have not been to the site before (or have saved cookies, etc.) then the site can't recognize you.

Then the Websie is one of those who log IP addresses is easy

Cookies are also just a variable that is also evaluated - just like the browser used.
It is simply difficult to say what companies evaluate and how.
This is a trade secret and is not communicated to the outside world.

For example, https://www.onlinetvrecorder.com is a site that checks something like this - but don't ask me what criteria they use. Fashcookies would occur to me - but whether they are (can) be saved across browsers is also beyond my knowledge.

In general, however, it increased the protection against tracking if you use different browsers.