How to Fix Wi-Fi Problems on Mac

The short answer. A Mac tells you almost everything about its Wi-Fi connection if you know where to look: Option-click the Wi-Fi menu and you get signal strength, noise floor, channel, PHY mode and transmit rate. Read those four numbers before you change any setting, because they separate the three problems that account for nearly every complaint — weak signal, congested channel, stale association — and each has a different fix.

This guide is the diagnostic order. It assumes you have already established that the internet works on other devices, because if it does not, the problem is upstream of the Mac and nothing here will help.

Read the numbers first

Hold Option and click the Wi-Fi icon in the menu bar. The menu expands from a list of networks into a technical readout, and four of those lines matter.

RSSI (received signal strength) is how loud the router sounds to your Mac, in dBm, which is negative and closer to zero is better.

Noise is how loud everything else is, also in dBm. A quiet environment is around −90 to −95; a noisy one is −75 or worse. The difference between the two is the signal-to-noise ratio, and that is the number that predicts whether your connection is stable. 25dB or better is healthy; below 15dB, retries climb and throughput collapses even though the signal looks fine.

Channel tells you which frequency you are on. Channels 1, 6 and 11 in the 2.4GHz band are the only three that do not overlap; everything else interferes with a neighbour. In the 5GHz band the channels are mostly non-overlapping by design, which is one of the reasons 5GHz is faster and more reliable at short range.

PHY mode is the protocol: 802.11n, ac, ax or be. If your router supports Wi-Fi 6 and the Mac is connected at 802.11n, something is wrong with the association or the band, and that is worth chasing before anything else.

For a continuous view rather than a snapshot, hold Option, open the Wi-Fi menu, and choose Open Wireless Diagnostics. Ignore the window it opens and use the Window menu instead: Monitor graphs signal and noise over time, Scan lists every network with its channel and strength, and Performance shows retries and errors. The Monitor graph is the single most useful thing in this article, because it turns “it drops sometimes” into “it drops when the signal falls below −72”.

On current macOS, wdutil info in Terminal prints the same information as text, which is useful when you want to compare before and after a change without watching a menu.

Fix 1: forget the network and rejoin

The cheapest fix and the one to try first, because it addresses the most common fault: a stale association.

A Mac remembers the security type, the channel and the BSSID it last associated with. When a router is replaced, its firmware updated, or its security mode changed from WPA2 to WPA3, the Mac may keep trying the old parameters. The symptom is a network that appears in the list, accepts the password and then fails to get an address, or connects and immediately drops.

System Settings → Wi-Fi → Details (next to the connected network) → Forget This Network, then rejoin and re-enter the password. This forces a fresh scan, a fresh handshake and a fresh DHCP lease.

If the network does not appear at all, Other… lets you type the name manually, which is the workaround for a hidden SSID and for routers that stop broadcasting after an update.

Fix 2: check the private address

macOS generates a random MAC address per network by default, under the name Private Wi-Fi Address. It is a good privacy feature and it breaks two things.

The first is any network that filters by MAC address — a hotel, an office, a router with an allow-list. The network sees a new device every time the address rotates and refuses it, or issues a new lease each time. Turning the feature off for that one network (same Details panel) fixes it, and it is a per-network setting, so you do not have to give up the privacy everywhere.

The second is a router whose DHCP pool is exhausted by the churn of random addresses. Less common, and the same fix applies.

While you are in that panel, check Limit IP Address Tracking. It is on by default, it routes DNS and some traffic through Apple’s relay, and on a corporate network it can look like a DNS failure. Turning it off is a legitimate diagnostic step, not a permanent recommendation.

Fix 3: DNS, leases and addresses

If the Wi-Fi connects but pages do not load, the problem is above the link layer, and the test is simple: does ping 1.1.1.1 work while ping apple.com fails? If so, it is DNS.

Renew the lease. System Settings → Wi-Fi → Details → TCP/IP → Renew DHCP Lease. This is the fix for an address conflict, which usually presents as a connection that works and then stops when another device joins.

Change the DNS servers. In the same panel, set DNS to something other than the router’s address. A router that is also doing DNS is a single point of failure, and a router whose DNS forwarder has hung produces exactly the “connected but nothing loads” symptom.

Check for a duplicate address. Two devices with the same static IP produce intermittent, maddening failures. If you set a static address manually, make sure it is outside the router’s DHCP range.

Check for a proxy. A proxy configured by an old network or by a piece of software will silently break everything. System Settings → Network → Wi-Fi → Details → Proxies: everything should be off unless you know why it is on.

Fix 4: congestion, channels and band steering

If the signal is strong and the connection is still slow, look at the channel.

Use Wireless Diagnostics → Window → Scan to see every network around you and which channel each one is on. In a dense building, the 2.4GHz band is usually a solid block of overlapping networks, and no amount of Mac-side configuration fixes that. The answers are, in order: move to 5GHz, move closer to the router, or change the router’s channel.

On 2.4GHz, set the router to channel 1, 6 or 11 — whichever the scan shows as least crowded. On 5GHz, leave it on automatic unless you have a specific reason; the automatic selection is usually better than a hand-picked channel because it accounts for radar and DFS rules you cannot see.

Band steering is the other half of this. Most modern routers publish one network name for both bands and decide which band each client gets. The decision is based on signal and history, and it sometimes puts a Mac on 2.4GHz when 5GHz would be better. If you want control, give the bands separate names on the router — Home and Home-5G — and join the one you want. It is a manual solution to an automatic problem, and it works.

Channel width matters on 5GHz: 80MHz gives more throughput but occupies more spectrum, and in a dense building a narrower channel with less interference can be faster in practice than a wide one with more. 160MHz is only worth it if you are the only network in range.

Fix 5: physical interference

Radio problems that look like software problems, in rough order of how often they are the cause:

• Distance and walls. 5GHz does not pass through two walls; 2.4GHz does, slowly. A Mac that is fine in one room and drops in another is describing the building.
• USB 3 devices. A USB 3 hub or an external SSD sitting next to the Mac radiates in the 2.4GHz band. Moving the device 30cm away sometimes fixes a connection that nothing else would.
• Metal. A desk, a filing cabinet or a monitor stand between the Mac and the router. Aluminium laptops with the lid closed on a metal stand are a worse antenna than the same laptop open.
• Other 2.4GHz transmitters. Cordless phones, baby monitors, microwaves, wireless keyboards, Bluetooth speakers.
• The router’s own position. On the floor, inside a cabinet, behind a TV, next to a fish tank. Routers are radios; they want height and line of sight.

None of this is subtle once you look for it, and all of it is invisible in the menu bar readout except as a noise figure that will not come down.

Fix 6: reset the network configuration

When the simpler fixes fail, the next step is to make macOS rebuild its network configuration from scratch. There are two levels, and they cost different amounts.

Remove the interface and add it back. System Settings → Network, select Wi-Fi, and use the … menu to Make Service Inactive and then reactivate. This rebuilds the service without touching the stored networks.

Delete the configuration files. In /Library/Preferences/SystemConfiguration/, the files com.apple.airport.preferences.plist, NetworkInterfaces.plist, preferences.plist and com.apple.network.identification.plist hold the network state. Removing them and rebooting makes macOS create new ones. You lose saved networks, static addresses and VPN configuration, so this is the last resort rather than the first step.

There is also the option of creating a new network location — System Settings → Network → … → Edit Locations — which gives you a clean set of interfaces without deleting anything. It is the reversible version of the same idea, and worth trying before the file deletion.

When it is the router, not the Mac

Half the Wi-Fi problems brought to a Mac are not the Mac’s. The tells:

• Other devices on the same network have the same problem. Check a phone before you change a setting.
• The problem started after a router firmware update or a new router. Almost always a security-mode or band-steering change.
• It fails at the same time every day. A scheduled task, a backup, or a neighbour’s device.
• Only one device is affected and it is always the same one. That is the device, not the router.

Router-side fixes worth trying, in order: restart it (genuinely — the uptime on a consumer router is the number one cause of mysterious behaviour), check for a firmware update, set the security mode explicitly to WPA2/WPA3 rather than “auto”, disable band steering if you have separated the bands, and move it.

If the router is supplied by an ISP and you cannot change those settings, a mesh system in bridge mode is the usual answer — it replaces the radio without replacing the routing.

When it is the Mac’s hardware

A Mac whose Wi-Fi fails in a specific way is describing a failing card or antenna. The signs: the Wi-Fi menu shows Wi-Fi: Off and will not turn on; the interface disappears from System Settings entirely; the machine gets hot and drops the connection together; or the signal is weak in a place where another Mac is strong.

Before concluding hardware, try Safe Mode (hold Shift at startup on Intel; hold the power button on Apple Silicon and choose your disk with Shift held). If Wi-Fi works in Safe Mode, a third-party driver or a login item is interfering. If it does not work in Safe Mode either, the card or the antenna is the suspect.

Antenna cables in laptops run through the hinge, and a machine that has been opened for a repair can have one pinched. That produces a signal that is weak in one orientation and fine in another, which is a distinctive symptom worth mentioning to whoever services it.

Office, hotel and campus networks

The networks you do not control fail differently, and the fixes are different too.

Captive portals. The sheet that asks you to accept terms is triggered by a redirect the Mac detects when it probes for connectivity. When the sheet does not appear, open a browser and go to http://captive.apple.com — the plain-HTTP address, not HTTPS — and the redirect will fire. If that fails, the portal may require HTTPS, in which case try any http site; if the network blocks plain HTTP entirely, you need the address the front desk gives you.

802.1X networks. These authenticate with a username and password or a certificate rather than a shared key. The usual failure is an expired certificate or a profile that was installed by an old MDM enrolment and no longer matches. System Settings → Privacy & Security → Profiles lists what is installed; a certificate with a date in the past is the answer, and only the network’s administrator can replace it.

MAC randomisation on managed networks. An office that registers devices by MAC address will see a new device every time the private address rotates. Turn the feature off for that network specifically, in the Details panel, and re-register.

Guest networks with client isolation. These deliberately block device-to-device traffic, which breaks AirPlay, AirPrint, screen sharing and file sharing between two devices on the same Wi-Fi. Nothing on the Mac fixes it; the network has to allow it, or you use a cable.

Proxy auto-configuration. Corporate networks often push a PAC file. When the file’s server is unreachable — because you are at home — every request waits for the proxy lookup to time out, and the result is a network that is connected and unusable. System Settings → Network → Wi-Fi → Details → Proxies, and turn off Auto Proxy Discovery and Automatic Proxy Configuration when you are not on that network.

Router settings that actually change the experience

If you own the router, a handful of settings are worth checking once. None of them are on by default in a way that helps.

Legacy rates. A router that still supports 802.11b clients slows the entire 2.4GHz band for everyone, because the slow client sets the timing for the cell. Disabling 802.11b/g rates, leaving only 802.11n and later, is one of the few settings that reliably improves a crowded 2.4GHz network.

Airtime fairness. This makes the router divide airtime between clients rather than letting the fastest one take what it wants. On a network with one slow device — a printer, a smart plug — turning it on improves everyone else’s experience noticeably.

IGMP snooping and multicast. Bonjour, which is what AirPlay, AirPrint and device discovery use, depends on multicast. A router with aggressive multicast filtering breaks discovery in ways that look like the Mac’s fault. If devices disappear from the sidebar but still work when addressed directly, this is the setting to look at.

DFS channels. Some 5GHz channels are shared with radar and the router must vacate them when it detects any. In an area near an airport or a weather station, that produces periodic drops that look like interference. Excluding DFS channels in the router’s settings trades a little spectrum for stability.

MTU. Rarely the cause, occasionally the answer. A PPPoE connection has an MTU of 1492 rather than 1500, and a router that does not adjust produces connections where small requests work and large ones hang — pages load halfway and stop. If that is the symptom, the MTU is worth testing.

Firmware. Consumer routers ship with firmware that is years old and never updated, and the update is usually the fix for behaviour that changed for no reason. It is also the single most common source of the problem when a network that worked stops working.

Tools worth having

The built-in diagnostics cover most of this. These add the parts macOS does not show.

The first two answer “why is my Wi-Fi bad”; the last three answer “what is my Mac doing on it”, which is a different question that people often ask by mistake.

FAQ

Why does Wi-Fi work on my phone but not my Mac? Different radios, different antennas and different band preferences. A phone may be on 5GHz while the Mac is on 2.4GHz, or the Mac may be holding a stale association for a network the phone joined fresh. Compare the two in the Option-click readout before assuming the Mac is broken.

Does a VPN slow down Wi-Fi? A VPN does not slow the Wi-Fi link, it adds a hop. Throughput drops because every packet goes through the tunnel and the encryption, and latency rises by the distance to the VPN server. If the connection is slow only when the VPN is on, the VPN is the explanation and the fix is a closer server, not a Wi-Fi setting.

Why does my Mac keep asking for the Wi-Fi password? Because it is not being saved, which usually means the keychain entry is corrupt or the network’s security type changed. Forget the network, rejoin, and if it still asks, check Keychain Access for a duplicate entry for that network name and remove it.

Is it worth upgrading to Wi-Fi 6E or Wi-Fi 7? Only if both ends support it and you have 6GHz spectrum available where you are. The benefit is a clean band with no legacy devices on it, which in a dense building is worth more than the headline speed. A Mac without 6GHz support gains nothing from a 6E router.

How do I test whether the problem is my Mac or my network? Create a Personal Hotspot on a phone and connect the Mac to it. If the Mac is stable on the hotspot and unstable on the home network, the network is the problem. If it is unstable on both, the Mac is.