Why Is My Internet So Slow?
There are many reasons your Internet connection might appear slow. It could be a problem with your modem or router, Wi-Fi signal, signal strength on your cable line, devices on your network saturating your bandwidth, or even a slow DNS server. These troubleshooting steps will help you pin down the cause.
Shutterstock Casezy Quality Of Service Qo Problem With Multiple Websites Test Your Internet Connection Speed Cellular Data Saturating Your Connection
Source: howtogeek.com