RUN WIRELESS DIAGNOSTICS
Modern versions of MacOS (since around Mountain Lion times) have a diagnostic toolbuilt it to check the wireless network. Start by running this tool: Hold down the “Option” key and select the Wi-Fi icon in the upper-right corner of your screen. Then select the “Open Wireless Diagnostics” option that has appeared there. Enter your login password if necessary, and wait for the diagnostics to complete.
When given a choice head to the summary of the diagnostics. Select the blue “i” button next to each summary note to learn more, and see if any of the notes include an important error or failure that you can note when pursuing solutions. If the diagnostics tool finds a major problem, it may stop diagnostics entirely and give you a pop-up window instead with a valuable description of what’s going wrong.
CHECK YOUR WI-FI CONNECTION AND RESTART
Is the Wi-Fi acting poorly for other devices, too? That’s a good sign that the network itself is at fault. It’s a good idea to start with a router inspection to see if anything is wrong. Do a physical inspection of the cables to make sure connections are secure. And make any changes if necessary.
Then you can reset your router to see if this helps fix your problem. Resetting a router can fix all sorts of issues, including problems with router updates, dropped connections, and lost connections with hard-line internet. Remember to unplug your router from the modem before you begin, and wait for a little while before turning your router back on to make sure the reset is a success.
UPDATE MACOS AND OTHER SOFTWARE
Have you recently updated MacOS? Sometimes, new updates can cause connection problems. In this case, you can roll back the update and wait: Wi-Fi problems in updates are, for obvious reasons, quickly patched. Tt should be no more than a day or so before you can update safely.
However, an update can frequently fix any problems you may be having with Wi-Fi problems, particularly if it’s been a while since you have updated your computer. So, check MacOS for any updates that haven’t yet been implemented, and see if your Mac recommends updating any router devices.
CHANGE PREFERRED ORDER OF SERVICES
Head over to “System Preferences in your Dock, and select Network. This gives you a closer look at your Wi-Fi settings and the network that you are trying to connect to. This screen can help you if you want to create a new Wi-Fi network or turn your Wi-Fi detection off and on again, but there’s something else you should try here as well.
On the left side, at the bottom of the list of detected Wi-Fi devices, look for the lock icon, and unlock it if necessary (your password will be required for this). Then, right above it, select the gear-shaped settings icon, and choose “Set Service Order.” Here, simply make sure that the Wi-Fi network you are trying to connect to is on top. If other devices are before it, then your Mac may not be giving that router enough attention.
CHECK YOUR TCP/IP SETTINGS
Search for the “Network Utility” app and open it up. This contains all sorts of information about your network, and can help you track down problems with your Wi-Fi. Once Network Utility is open, you can use “Info” to look at router settings and send/receive errors, which may help you see what’s going on. To check on configurations, head to the TCP/IP tab.
If you don’t see your IPv4 address here, or something else seems unusual, select “Renew DHCP Lease” which offers a basic reset of your network connections.
If this doesn’t work, try contacting a network administrator or looking up your local ISP information to check what the settings should be in the TCP/IP and DNS tabs, and change the information accordingly: This is rarely a problem with modern networks, but sometimes you have to go in and manually make sure that all your settings are correct.
REMOVE ALL YOUR ACCESSORIES
We know it sounds weird, but your accessories could be blocking your Wi-Fi signal. This may be even more common on newer Macs with USB 3.0 and Type-C ports, which may be creating opposing signals that interfere with the Wi-Fi signal. The best way to test this out is simply unplug your peripheral devices and reboot your Wi-Fi to see if you can connect. If this works, try to narrow down what specific connection is messing up your Wi-Fi.
Unfortunately, there’s not much you can do except avoid using that particular device on your Mac, or only using it when you don’t need to connect to the internet.