top iPhone 8 internet speed?

iPhone 8 supports 802.11ac, which at the time of the 8 introduction could be up to 1,300 Mbps or 1.3 Gbps.

Of course, your ISP would have to be delivering those speeds and the Wi-Fi router would have to be capable of handling those speeds. The iPhone 8 would have to be very close to the router as well.

Most routers that claimed 1,300 Mpbs speeds typically checked out at about 700-800 Mbps.

Real world, the iPhone 8 might check out at 500-600 Mbps on a great day.

Cellular data, best the iPhone could do on an LTE or 4G connection....I don't know, but I would be surprised if it was much over 50 Mbps if that.

The iPhone 8 supports 4G/LTE, so the limit will be the network, not the phone. I have gotten up to 90 mbps (rarely), but generally 20 - 40 mbps.

My iPhone 14 on T-Mobile 5Guc has been as high as 650 mbps, but even on plain vanilla 5G I’ve gotten over 100 mbps.

Theoretically, in the best circumstances, with no interference or blockages of any kind, and appropriate wwi-fi router, 1.3Gbps on 802.11ac Wi-Fi.