I know I could get a flash drive with a lightning jack or with both a lightning jack and a USB jack, but is it feasible to transfer files between an iPhone XR running iOS 13.3 and a USB flash drive using a lightning cable and a female-to-female USB connector as follows?

iPhone 🔹 lightning to male USB cable 🔹 female-to-female USB adaptor 🔹USB flash drive

  • 1
    Go with the flow. Get the combo drive. Feb 20, 2020 at 22:51

2 Answers 2


This is not likely to work. The Lightning port on Apple devices work in many ways like the mini-USB On-The-Go ports from older phones and USB-C ports on newer phones. This means it can act as a USB host or device, just the means by which an iPhone determines which mode it should be in is different than how devices with USB-OTG ports do.

In USB device mode, which happens with a Lightning to USB-A male cable, the iPhone provides no power to the cable. This means that a female to female adapter which connects the data and power lines will not power the flash drive, and the flash drive will not have power to do anything. Connecting both to a powered hub so that both the phone and flash drive have power will still leave this USB bus with no host to initiate any communications.

It's unlikely any software on the iPhone will resolve this because the hardware on the phone is simply not made to act as a host when the hardware tells it to go into device mode.

USB from 1.1 on up was made to allow for host-to-device communications and what you describe is a device-to-device connection. USB 2.0 allows for ports to be switched into either host or device mode, but this is done in hardware. If there is a means to override this in software then it is violating the spec and could result in damaged hardware, if someone could find the software for this then you run the risk of damaging your iPhone the next time you try to charge it. USB 3.0 allows for host-to-host communications with the right kind of cable and software but the flash drive is simply not going to act as a USB host.

To make this work will mean violating the USB spec, and running the risk of permanent damage to your phone. There's going to be at a minimum software checks in the iOS to stop this from working, and quite likely the hardware in the iPhone simply will not enter host mode if it sees a USB-A male cable connected.


I was always under the impression you needed the USB camera adapters for this to work.

I can’t seem to find a reference explaining why you need additional chipset to act as a hub or if this is designed into the iOS lightning controller but my hunch is physically connecting as you describe isn’t enough and there isn’t a female to female USB-A part that will work to pass the data correctly.

  • I've now tried this and the light doesn't come on on the flash drive, so for some reason it isn't getting powered by the iPhone. (But I haven't given up. I'll search for an app that might solve the problem.)
    – user341810
    Jan 20, 2020 at 14:37
  • From what I understand, the camera adapter is just an OTG adapter. A regular USB adapter doesn't have the "logic" to say which device supplies the power. This device solves that.
    – Allan
    Feb 21, 2020 at 2:57

You must log in to answer this question.