Questions that I see from time to time ask about Internet slow downs. There are numerous possible reasons for your Internet to appear slow. I’ll suggest a few of them and possible remedies. I’m going from memory that might be a few years out-of-date, so feel free to correct or add to this list.
Probably the first thing to do is get a baseline of your Internet speed. This fast and simple test will let you know if it is, in fact, slow and give you a baseline to work from to see if something you try has a beneficial effect. For decades, I have used Speakeasy.net’s Speedtest and click on the nearest location. There are other sites that do the same.
One of the first thing to check is to see if someone in the house is streaming music or video, or uploading the same. Those will likely be taking up a large amount of available bandwidth.
I’ve often seen computers that were automatically connected to a file sharing site (Peer to Peer or P2P) and unknowingly uploading files. Since most people don’t RTFM (Read The Fine Manual), they don’t realize that by installing P2P software, their computer and bandwidth is used to upload files to other people’s computers. This is dangerous for a number of reasons. P2P File Sharing Programs
Sometimes it’s just a bottleneck created by your computer and rebooting will fix it. Restarting the modem will sometimes fix it. Sometimes the fix requires power cycling the modem but that is usually only necessary for when you can’t get online.
Sometimes, there’s a bottleneck in the Internet that is affecting traffic over a wide area. Internet Traffic Report will show if there’s a major problem.
Sometimes it’s a problem with the Domain Name Servers (DNS) that your computer or router are using to translate a domain name into language that computers understand. As an example, Gorge.net will be translated by DNS to the IP (Internet Protocol) address of 220.127.116.11 .
Not all DNS are the same. How to Find the Fastest DNS Server Near You can help you choose and configure the best DNS for you, if you desire.
Another possible reason for your Internet being slow is because a computer on your network is being controlled by malware to send out a stream of spam or be involved in a DDOS (Directed Denial of Service) attack. It might not even be what you would consider a computer or device (smart phone/pad, etc) but a device such as a NEST thermostat or smart fridge, or a router.
IoT devices recently created the largest DDOS attack against a security site. If you have any such devices, make sure they are not using default usernames and passwords. IoT Devices as Proxies for Cybercrime from KrebsOnSecurity.com has more information.