AirPrint printer not found: 7 checks in the right order
Your iPhone says "No AirPrint printers found", but the printer is on and the Wi-Fi light is lit. In most cases the printer is fine and the phone cannot hear it. Start at the top and stop when it works.
Why this happens
AirPrint finds printers through Bonjour. The printer announces itself with a small multicast message on UDP port 5353, and your phone listens for it. If that message does not reach the phone, no printer appears. That happens when the two sit on different networks, when the router blocks the message, or when something on the phone redirects network traffic.
1. Put both on the same network
Phone and printer must be on the same Wi-Fi network. A guest network does not count, and neither does a second network from a mesh system or range extender that has its own name. If the router has separate 2.4 GHz and 5 GHz networks with different names, connect the phone to the one the printer uses.
2. Turn off the VPN
A VPN sends your traffic away from the local network, so the phone no longer sees local devices. Switch off the VPN for the test. You find it under Settings, VPN if it is set up there, or in the VPN app itself.
3. Turn off Private Wi-Fi Address for this network
Go to Settings, Wi-Fi, tap the i next to your network and switch off Private Wi-Fi Address. Some routers and printers handle the changing address badly.
4. Check the printer
Restart the printer. Check that it is on the same network and that AirPrint or IPP printing is switched on in its settings. Print a network configuration page and note the IP address. You need it for step 6.
5. Look at the router
Two settings cause most router problems. Client isolation, sometimes called AP isolation, stops devices on the Wi-Fi from seeing each other. Switch it off. Multicast or mDNS filtering can block the Bonjour message. Allow it. Where these settings sit depends on your router, so check its manual or support page.
6. Test the connection without Bonjour
On your phone, open a browser and type the printer's IP address, for example http://192.168.1.45. If the printer's web page opens, the network path works and only discovery fails. If nothing loads, the phone and printer are not on the same network, and step 1 or 5 is the cause. In your router, reserve this IP address for the printer so it does not change.
7. Print without AirPrint
If discovery keeps failing, use the manufacturer's app, such as HP Smart, Canon PRINT or Epson iPrint. Or connect the printer by cable once. Many people find that this brings the printer back, because the printer then does not need to be found over the network.
Frequently asked questions
Why does my Mac print but my iPhone does not?
The Mac can reach the printer another way or is on a different network from the phone. Check steps 1 to 3 on the phone.
Why did it work yesterday?
The printer probably got a new IP address, or an update reset a router setting. Reserve a fixed IP address for the printer in your router.
Does a USB cable fix it?
A cable lets you print without the network. Whether it also repairs the wireless connection depends on the printer.
I am building a small app that runs these checks for you, tells you which one fails, and prints directly to the printer's address if discovery stays broken. It is not finished. If you want to hear when it is ready, you can join the waitlist.