Why is my Wi-Fi so bad all of a sudden? How to find the cause and fix it

Your Wi-Fi was fine last week. Now videos buffer, calls freeze, and pages hang on a blank screen.

By the end of this guide you'll know whether the problem is your device, your router, or your provider, and you'll have fixed the most common causes.

The short answer

Check whether every device is slow or just one. If everything is slow, check your provider for an outage, then unplug the modem and router for a full 60 seconds and power them back on in order. That clears up most sudden slowdowns. If it keeps coming back, change your Wi-Fi channel and update the router's firmware.

Before you start

• What you need: your phone, the device that's acting up, and access to your router (the box with the Wi-Fi lights).
• Time: 10 to 30 minutes.
• Write down your Wi-Fi name and password before touching router settings. You'll need them if anything gets reset.
• No personal files are at risk here. Router settings are, so don't press the router's reset button unless a step tells you to.

Step 1: Find out if it's one device or all of them

This tells you where to look. One slow device means a device problem. Everything slow means the router or the provider.

1. Open the same website or video on two or three different devices.
2. Run a speed test on each at speedtest.net or fast.com.
3. Stand near the router and run the test again on the slow device.

If only one device is slow, skip to Step 4. If everything is slow, keep going. If it's only slow in certain rooms, that's a coverage problem, not a sudden failure. Our guide to Wi-Fi dead zones in prewar and railroad apartments covers that.

Step 2: Check for a provider outage

Don't spend an hour troubleshooting your router if the problem is on the provider's end.

1. Turn off Wi-Fi on your phone so you're on cellular data.
2. Open your provider's app or sign in to your account on their website. Look for an outage or service status alert.
3. Look at the modem's lights. A blinking or red "online" or internet light usually means the provider's signal isn't reaching you.

If there's an outage, you wait it out. Nothing on your end will fix it. Optimum customers can follow our Optimum outage guide.

Step 3: Restart the modem and router the right way

A quick power flick doesn't do much. The equipment needs time to fully clear its memory and get a fresh connection from your provider.

1. Unplug the modem and the router from power. If your provider gave you one combined box, unplug just that.
2. Wait a full 60 seconds.
3. Plug the modem back in first. Wait until its internet or online light is solid, usually 2 to 5 minutes.
4. Plug the router back in. Wait another 2 minutes.
5. Run a speed test again.

If it worked, your speeds should be back near what you pay for. Your devices should also reconnect on their own.

Step 4: Forget the network and rejoin it

If only one device is struggling, its saved connection may be corrupted. Removing it and reconnecting gives the device a clean start.

iPhone

1. Go to Settings → Wi-Fi.
2. Tap the (i) next to your network, then Forget This Network.
3. Tap your network again and enter the password.

Android

1. On Samsung, go to Settings → Connections → Wi-Fi. On Pixel, go to Settings → Network & internet → Internet.
2. Tap the gear icon next to your network, then Forget.
3. Tap the network and rejoin.

Windows 11

1. Go to Settings → Network & internet → Wi-Fi → Manage known networks.
2. Click Forget next to your network.
3. Click the Wi-Fi icon in the taskbar and reconnect.

Mac

1. Go to System Settings → Wi-Fi.
2. Click Details next to your network (on some versions, click the ⋯ button), then Forget This Network.
3. Select the network and rejoin.

Restart the device too. If the whole computer feels sluggish and not just the internet, see why your computer is suddenly slow.

Still not working? Try these

Change the Wi-Fi channel

Routers broadcast on channels. If your neighbors' routers crowd onto the same one, everyone slows down. In a New York apartment building, your phone can probably see a dozen or more neighboring networks, so this is a common cause.

1. Open your router's app, or type the address printed on the router's label (often 192.168.1.1 or 192.168.0.1) into a browser and sign in.
2. Find the Wireless or Wi-Fi settings. It may be under Advanced.
3. For the 2.4 GHz band, choose channel 1, 6, or 11. Those are the only ones that don't overlap each other.
4. For 5 GHz, try a different channel than the one in use, or set it to Auto.
5. Save and give devices a minute to reconnect.

Update the router's firmware

Firmware is the router's built-in software. Updates fix bugs that cause drops and slowdowns.

1. In the router app or admin page, look under Administration, System, or Advanced → Firmware Update.
2. Install any available update.
3. Don't unplug the router while it updates. Interrupting it can leave the router unusable.

If your provider rented you the router, it usually updates itself. Call them if you suspect it's stuck.

Find what's hogging the bandwidth

A cloud backup, a game download, or a phone uploading photos can eat your whole connection. Check the router app's list of connected devices for one using a lot of data. Pause it and test again. If you see a device you don't recognize, change your Wi-Fi password.

Move the router

Routers belong out in the open and up high. Inside a cabinet, behind a TV, or next to a microwave or fish tank, the signal gets blocked. Moving it just a few feet can help more than you'd expect.

Switch bands

The 2.4 GHz band reaches farther but runs slower. The 5 GHz band is faster up close. If your router shows two network names, try the other one. If the drops keep happening even after all of this, work through router keeps dropping Wi-Fi.

Keep it from happening again

• Restart the modem and router once a month, or set a scheduled reboot in the router app if it offers one.
• Turn on automatic firmware updates in the router settings.
• Replace an aging router. If yours is old enough that the manufacturer stopped releasing updates for it, it's time.
• Keep the router central, elevated, and out of cabinets.

Quick answers

Why is my Wi-Fi bad only at night? Evening is when everyone in your building and neighborhood is streaming. Some of that is provider congestion you can't fix, but changing channels often helps.

Will a factory reset fix it? Sometimes, but it wipes your Wi-Fi name, password, and settings. Try every step above first, and write your settings down before resetting.

My speed test looks fine but things still lag. Why? Speed isn't everything. Drops and delays can come from interference or a weak signal, which a single speed test can miss. Test in the room where the problem happens.

Rather have us fix it?

If you've worked through this and the Wi-Fi is still crawling, an ITGoNYC tech will come out, test every link from the modem to your devices, fix the channel and firmware issues, and tell you straight whether your router needs replacing. Call or text 347-549-9059 now for same-day help, or open a ticket and we'll book an on-site visit.