Does Sharing Wi-Fi Make It Slower?
Sharing Wi-Fi access over several devices can slow down service if the devices use all available bandwidth. Wi-Fi access points, commonly referred to as wireless routers, are rated for total available bandwidth, which is split between connected devices. Consequently, Wi-Fi networks under a high user count or heavy traffic load can benefit from a higher-bandwidth router.
1 Shared Wireless Bandwdith
Wireless routers have to split bandwidth between all devices, but it's not a performance issue until all the bandwidth is used up. The only time you'll notice a slowdown is when one or more of the connected devices is running something bandwidth intensive. For example, five users browsing the Web and checking email will probably not be enough traffic to slow down connections; however, two users streaming high-definition video content over the network may consume all available bandwidth and cause the network to slow down.
2 Other Performance Issues
You may also get slower wireless performance from a router if you have dozens of wireless devices connected to the same access point. Wi-Fi is a radio technology, and the devices have to share the same broadcast frequency. The more devices connected to the router, the greater the chance of connection interference. However, interference is not a problem associated with the router itself, but is rather due to all the devices trying to communicate on the same frequencies.