WiFi slower when using extender TP-Link RE450

that shows that you connected to your extender all right. really good signal strength (RSSI) and it is running really well, and giving the absolute best speed it can, on its 20 MHz connection on 2.4 GHz, 213 M bits/sec using three antennas.

To go faster, you would need an access point that supports 5 GHz as well (or instead of) only 2.4 band.

wait, I see a separate 5GHz connection "alleged_5G_EXT". Can you connect to that instead?

<< It will connect but almost doesn’t load anything. >>

if you mean LITERALLY what you said, check your DNS numbers. DNS does human-readable site names (Domains) to "internet Phone number" lookups. bad or missing DNS means NO web sites will come up by name.

the following post contains a DNS server test

if what you meant was the TITLE, that it works but is much slower, then these diagrams may help you understand.

when you make a WIRED Ethernet connection between Wi-Fi extenders, you get a full speed connection:

if you decide to use an over-the-air connection between access points, that immediately takes half the bandwidth for forwarding. if the access point is too far away from the main Router, speeds will decline further:

...

hold down the option key while you click on the WiFi Icon on the menubar, you get a report of current parameters like the older one posted here. screenshot, photograph, or transcribe the parameters and post back here.

...

If your running your iPhone on the same system at the same as your Mac there is only so much bandwidth that the extender can supply. I probably would have gone with a Mesh system, rather than a Extender. You should get hold of the specs for the Extender and touch base with tech support to find out if it set up correctly.

Launch a browser and enter this easy to remember all-numeric IP address:

http://1.1.1.1

in the address bar, and press return.

If you get the CloudFlare** splash page, your internet is working, but DNS lookup may not be working.

**CloudFlare is NOT part of the solution, they just own the easiest to remember all-numeric IP Address.

Those are the OpenDNS numbers. That should be working great, and 'getting the splash page' says your DNS is not the issue.

can you please clarify whether you meant to say:

"Not working AT ALL" or

"Working, but much slower" ??