WiFi extenders can help with situations where you have annoying "dead spots" in your home, despite fiddling around with WiFi broadcast channels and moving things around. Some help more that others, and the folks at The Wirecutter spent some time researching to find the best performing device they could come up with, the Netgear EX6200. This is a chunk of money at around $100, but if you are in a tough spot, and need the best connection possible for your streaming needs, it could be well worth it.
WirecutterIn our tests, the EX6200 could stream 1080p YouTube videos to three laptops at the same time (one up to 63 feet away), and it was the only extender we tested that could stream a 4K YouTube video to a single laptop, outside the house, at the same distance. The Netgear EX6200 had the best long-range performance of the extenders we tested (35.4 Mbps), even through exterior walls. It was the easiest to configure, and because it's an AC1200 wireless-ac extender, it supports the fastest connection speeds of dual-stream Wi-Fi devices.