Why has my Internet Download Speed suddenly become slow?

derpy, that may be the case but that usually does not work. well it does, but that requires you to wait a few minutes to about an hour for the modem and router to recycle through a new external ipv6 - ipv4 address. check how fast your internet connection is at speedtest.net and see if the problem is still there.(check to see if your router is the problem, overheating and not enough transfer speed between the computer and the access point is usually the culprit and you might want to get a dual band gigabit router) if it is, and if derpy's solution still does not solve the problem, then of course, contact your ISP and have them send someone over to check the modem and/or router (if they can)

Something maybe wrong with the connection. Contact your internet provider and they can run a test to figure out the problem. You shouldn't be charge for the test or even if they send someone over to your house as that is normally all covered on any internet plan.

After a certain amount of data usage the ISP, in the name of Broadband Fair Usage Policy, reduces the speed. Check ur ISP Broadband Fair Usage Policy.

It could be alot of things. Throttling, network card issues, weather if you're on wireless, serverside issues or a dozen other things. Ask your ISP

How you tried restarting your modem and router? sometimes when my connection is not so good I just restart my modem and router and it refreshed it self and I got my actual speeds again..sometimes it dumps bandwith in the router so restarting it should fix the problem!