Your Mac says the printer is offline, but it's switched on
Nine times in ten the printer has joined a different Wi-Fi network than your Mac — which happens after a router change, a power cut, or a new broadband box. Your Mac keeps the old address and reports it offline.
First, work out which end the problem is at
This is the part almost nobody can do for themselves, and it decides everything that follows. Your Mac saying "offline" only means it cannot reach the printer. It doesn't say whether that's the printer's fault or your Mac's.
The test: can your Mac see anything else on the network? If it can see your TV, your speaker, your router — but not the printer — the printer is the odd one out and you should go and look at the printer. If it can't see anything, your Mac's network is the problem and the printer is innocent.
PrinterAI does exactly this check automatically, and says which of the two it is: "I can see other things on your Wi-Fi, so this computer is fine."
If the printer is the odd one out
- Switch it off and on again. Power button, wait until fully off, count to thirty, back on. This fixes more than everything below it put together.
- Check its own screen. Most printers show their network status on the machine and nowhere else. Look for a Wi-Fi symbol or a network menu.
- Check which network it's joined. After a new router, printers commonly stay looking for the old one. Many are only on 2.4 GHz, so if your router made separate 2.4 and 5 GHz networks, the printer may be on one and your Mac on the other.
- Unplug it from the wall for a minute — not just off at the button.
If your Mac can't see anything
- Are you on a work VPN? Those routinely block the traffic printers are found by. Disconnect and try again.
- Is your Mac on a cable while the printer's on Wi-Fi? They can end up on separate networks that cannot see each other.
- Guest Wi-Fi deliberately isolates devices from each other. A printer on the guest network is invisible by design.
What not to bother with
Reinstalling the driver won't help an offline printer — the driver isn't involved until your Mac can reach the machine. Neither will removing and re-adding the printer, though it's worth doing after the printer is back on the network if your Mac still won't use it.
The one that gets missed
If your Mac lists the same printer twice, one of the two may be pointing at an address that no longer exists — so it reports offline forever while the other works fine. That's worth checking.