Why an iPhone Cannot Print Through a Cable, and What Owners of Older Printers Can Do Instead
Apple's iPhone and iPad have supported AirPrint wireless printing since 2010, but iOS and iPadOS never included native printer drivers, so a cable connection cannot work even with an adapter. Apps and bridge software exist, though most route jobs through a computer.
Since late 2010, the iPhone and iPad have supported AirPrint, Apple's wireless printing standard. Manufacturers including HP and Canon also offer standalone apps that add wireless printing to some printers that lack AirPrint, but Engadget noted that the catalog of supported models only reaches back so far. As wireless printing became the default, users of older hardware found themselves without a straightforward path from an iPhone to a printer.
The obstacle is drivers. Every printer model requires its own driver set. On desktop operating systems those drivers can be downloaded from the manufacturer's website; on iOS and iPadOS they cannot. Apple chose not to support native drivers because handling the many variations among device drivers would be a considerable burden. The practical result, Engadget reported, is that plugging an iPhone into a printer — which is possible with special adapters that enable USB On-The-Go — does not make the two devices communicate.
Apps do not close the gap either. Some Android apps support direct USB printing, but no equivalent exists on iPhone, a notable difference between the two platforms. Apps such as PrintCentral Pro, PrintDirect and PrintCast offer partial help, though they rely on a computer acting as a middleman rather than printing directly from the phone to a USB printer.
Software such as Printopia can force a USB printer to appear as a wireless printing option by creating an AirPrint bridge, but that approach also requires a computer. At that point, Engadget noted, emailing the document or photo to yourself and printing from the computer is the simpler route. More elaborate setups are possible, including a Raspberry Pi running as a print server.
For people who need to print from a phone regularly, Engadget's assessment is that upgrading to a modern, AirPrint-equipped printer makes more sense than assembling a chain of adapters, apps and intermediary computers.