Iphone 11 wifi speed very slow

Hello MTae,

Thank you for using Apple Support Communities! I understand that Wi-Fi on your iPhone 11 is slower than the connection you were getting on your iPhone 6s. It sounds like you've already done some great steps to resolve this issue, and I would be happy to help with what to do next.

To help us further isolate potential causes, I'd like to have you try the following on your iPhone 11. Test if the Wi-Fi speed changes after each step:

1. Ensure the iPhone is updated to the latest iOS, which is currently iOS 13.3.1: Update your iPhone, iPad, or iPod touch
2. If there's a case on the iPhone, remove that and disconnect the device from any accessories.
3. Connect the iPhone to a different Wi-Fi network.
4. Turn off Bluetooth from Settings > Bluetooth
5. Turn off LTE from Settings > Cellular

If the issue is happening only with a specific Wi-Fi network, consider moving the router to a different location where there may be less interference (Resolve Wi-Fi and Bluetooth issues caused by wireless interference). Also ensure that the network configurations for your router meet the following recommendations:

Recommended settings for Wi-Fi routers and access points

If you have VPN or security software installed under Settings > Safari > Content Blockers, Settings > General > VPN, or Settings > General > Profile, temporarily uninstall those as it could affect connectivity. Keep us posted on the results.

Cheers!