It all depends on the size of your house and how many walls the signal has to travel through. If your wi-fi transmitter is installed at a high location, that is generally best for signal strength.

We have a NetGear signal extender. I have it plugged into the halfway point of the house and it covers upstairs and the master bedroom area. It wasn't terribly expensive ($50?) and they are coming down in price. My advise is to stick to the name brands (Linksys, Belkin, NetGear) and for best performance, try to match the brand to your existing equipment. Less compatibility issues to worry about.

If you had good coverage and this is a sudden change I would look at the router itself for a problem. First thing to consider is if there's a new firmware update for your model. Just go to the manufacturer website and look for your model and updates. Depending on the router you might be able to have it find and install the update itself. Firmware updates are fairly common. If you have a degradation in the signal strength and no updates you might need a new router, they do fail.

I have a netgear extender in my bedroom because it's so far from the router. Without it I have one bar with it I have full bars.

Have you done speed tests from various rooms to see how much speed drop you are having? I would do that as well.

This is one I use which works well on Android too.

Speedofme

When there's a sudden change in one location, the first things I suspect are either a movement of physical items like furniture or other stuff to block the signal, or a neighbor causing broadcast congestion by using the same Wifi channel.

About channels - While there are theoretically 11 available "channels" on the traditional 2.4 Wifi band, interference really limits clear settings to using one of three- Ch 1, Ch 6, and Ch 11. Get a free wifi analyzer app for your smartphone or tablet, and see what's visible to your devices. If you see congestion, switch your channel setting to one where it's less crowded (done by logging on to the router). Most routers have a default setting of Ch 6 and few people change it, so often either 1 or 11 will give you better performance. Or, if your devices are dual band, try enable the 5Ghz frequency broadcast and see if there's any improvement.

If neither of those two ideas helps, try a repeater and I agree that sticking to the name brands is a good idea. With one exception: I have a Hawking Extender and like it very much. I've long had Linksys routers and prefer them. When range extender time came for me (maybe 4 years ago), I thought I'd try a Linksys model, assuming maybe the line had good quality. I got the WRE54G, it was an awful piece of junk, both hardware and software wise, no other description fits. I threw it away, I was too frustrated with a month long setup failure to return it. A techie friend recommended Hawking, and it turned out to be everything the Linksys wasn't and to have every feature the Linksys lacked.

Maybe the Linksys product is better now. Home networking equipment is known to be shoddy, one specific item can be great while another new one of the same model (sitting next to it on a shelf) can be awful. I wouldn't call Belkin one of the better names, but certainly among D-link, NetGear, Linksys (and Hawking if still making one) you'll fine something that will work. There's no need to match brands with your router, all send and receive the identical signal. In fact, there are only a couple of companies that make the chips, so that many brands are identical inside (as far as physical components) and differ only in their firmware (software) and user interfaces.

Buy it from a seller that will allow a return without a restocking fee.

Edit for PS-

For those with large houses, or the need for high bandwidth in Wifi (as for streaming TV or multiple users doing that), an alternative setup is to get two powerline devices (to run the signal first over your house's electrical wiring). One powerline dongle connects via ethernet cable to your router and plugs into a wall socket (not a power strip), the other dongle plugs into a wall socket at the far end and has an ethernet cable run to a nearby WAP (Wireless Access Point) device. The WAP puts out a Wifi signal, but the powerline devices run that captured signal over wire to the router.

Using a repeater cuts bandwidth in half, because the signal needs to be sent twice (from router to repeater, then repeater to device, and the same in the opposite direction) for communication. With a WAP, it's sent only once. So that's maybe 12-14 megs of throughput instead of 6-7 with a repeater

Thank you all for your responses. After reviewing everything I could, I believe my router is going on the blink. Whenever I touched it yesterday, it was very hot which has not happened before. My granddaughter was in the room with the router last night not more than three feet from it and could not get a Wi-Fi signal on her laptop. Regardless, I ordered a new router so will see if that is the problem. And I just checked my cell phone (I am sitting right next to the router) and it was not showing even one bar. If the router is not the problem, will return the new router, but I truly think that is what is the issue.

Agree, sounds like you're on the case, WC. If it's much more than 5 years old, the heat + signal problems are pretty conclusive.

Heat is a bad sign in anything electronic (said by someone who in the last hour noticed the home server was acting erratically and was WAY too hot. After triggering backups to be to be sure to be current, I ordered a replacement that will arrive on Friday)

Yes, I did check out Amazon for the extender before I ended up ordering a new router, TJ.