Inside Marshmallow: USB connection options

You have an extra step when you want to transfer files to and from a computer using a USB cable in Android Marshmallow.

When you plug your Marshmallow-powered phone into a computer — Windows, Mac or Linux makes no difference — you'll have to tell the operating system what you want to do.

By default, your phone (or tablet) will be in USB charging only mode. This means no data is going back and forth between your phone and your computer's USB port, and only the 5 volt power is active. That's good for charging the battery, but means you can't see the phone in any type of file or folder browsing software, and the Android File Transfer app for Mac computers will pop out an error. Every time.

What you'll need to do is go into your notifications, and tap the USB connection entry. You'll get a dialog that allows you to change things.

  • Charging only is the default, and is used when all you want to do is top off your battery.
  • Transfer files (MTP) lets you copy files back and forth between your phone and computer using the Media Transfer Protocol. This is likely the option you'll want if you need to copy some files.
  • Transfer files (PTP) lets you copy files (usually only photos or video) using the Picture Transfer Protocol. This modes makes your computer think you have a digital camera attached, so programs that were designed to connect to a camera can grab photos and video directly from your phone and import them automatically.
  • MIDI is the option you'll use if you want to connect a MIDI device — something like a MIDI keyboard — to your phone or tablet and use a synthesizer app to create music.

These look like good options all around. The inclusion of MIDI support will make a lot of people happy, and MTP and PTP are options we've been using for a while. The issue is that you can't set any of them as the default, and you need to choose each and every time.

Choosing the correct option is not a difficult step, but in previous versions you could set a connection type as a default. This feels like a step backwards, and any of the reasons we have seen or can think of don't seem very sound. Here's hoping Google gives us a default setting option back in a future update.

Jerry Hildenbrand
Senior Editor — Google Ecosystem

Jerry is an amateur woodworker and struggling shade tree mechanic. There's nothing he can't take apart, but many things he can't reassemble. You'll find him writing and speaking his loud opinion on Android Central and occasionally on Twitter.

  • Thanks Jerry... Side note, I am taking an interview with a Hildenbrand tomorrow. Got family in the philly area? +++ Insert witty signature, watch as others not get it, profit +++
  • Neat. I have family in Pittsburgh, but not Philly. Probably not Uncle Gary :P
  • OK cool +++ Insert witty signature, watch as others not get it, profit +++
  • There's someone who now doesn't get the job. ;)
  • There is also a Audio Source option? It is also listed under Developer Options > Select USB configuration. Would be nice if the OP can update it
  • Dev options are one-time use only. There is also an option to force MTP as default, but it doesn't stick after the session is completed.
  • If you are using the nexus 5X or 6P do you see the option to charge out? At google I/O they demonstrated that with a type C to micro usb male cable you could charge a buddies phone off your battery. With the big battery of the 6P I can imagine a few instances were this would be handy.
  • Actually when I select MTP in the Dev-settings I'm using that as default. I can access my phone with the file browser on my computer even though it says "Charging only" in the notification area. To my understanding this should be possible if the "Charging only" were true.
  • bullshit, then your device works wrongly, mb chinese one
  • true, it works only one time, on the second it's again f* charging
  • I set the option under Developer Tools, it still asked me the question in notifications, when I plugged it into my laptop nothing popped up either on the tablet or the laptop. However, when plugged into my Desktop the PC installed some Nexus drivers and popped up a dialog, and the notification popped up on my Tablet. I am so sick to death of all the o.s. updates. When everyone raves about one working super well they should just leave it alone and let us have that.
  • what does the audio source option do? it would sound like allow you to output audio from the phones speaker when source device is connected to smartphone via usb. hence "usb configuration, audio source". is this correct, and if not could you guide me towards its correct use?
  • Another thing for custom ROM makers to fix. My suspicion is that Google wants to try and nudge people towards cloud services rather than a good ol' USB cable, but I'm the paranoid type. Posted via the Android Central App
  • I don't think you're paranoid.
    Though it now seems what everyone has been sayin about you is correct. ;)
  • And while they're at it, please Google, please for the love of God, give us a box to check off so we don't always have that message pop up when turning up the volume! I know this is falling on deaf ears but damn it that pisses me off to no extent Posted via the Android Central App
  • I don't see this ever happening. If the box was ever checked by accident the average user would never figure out how to enable it again. Unless I'm thinking of a different dialog box than you.
  • This doesn't happen on stock Android. I've turned up my volume to "unsafe levels" countless times (almost every day for the past year) and haven't ever received that message. I do know what you're talking about, as I've had it during my stint with the Samsung Note 3. :P
  • I'm under the impression this will never happen under [international] law, where [international] is either europe or america. I can't remember where I'm living when I have this problem. But I guess whichever continent you're on. Google have had to comply with a directive about saving people's ears via headphones, but IIRC it's via the headphone SOCKET, so bluetooth headphones are ok.
  • Are you in Europe? I've never seen this in the US except when I put a European SIM in on vacation.
  • Root and there is a Framework module to disable the annoying warning..
  • "this is falling on deaf ears",
    no pun intended? ;-)
  • "The inclusion of MIDI support will make a lot of people happy" Um, no. It would make ME happy, since I use MIDI (rarely). But a lot of people? I think you overestimate the number of people who use MIDI for anything, much less the number of people who want their phone to do MIDI.
  • Lel you upset? And you can't say that he's over estimated by using your own logic you dweeb. Get over it kid. Posted via the Android Central App
  • Oh side note. People will be able to use it on tablets as well so that will broaden the usage too. But I guess you're to close minded to understand. Posted via the Android Central App
  • What number of people do you need for you to be happy with the term "a lot". I think 1,000 people is a lot, and there's pretty much certainly a lot more than that who will be happy. In my immediate social group, I can think of 5 or 6 people, so extrapolating that out to the user base should manage to reach "a lot". And it's not just that it can do it that's important, but the sign of intent from Android that it considers music creation to be an area that needs improvement. So your evidence that the statement is wrong is what exactly?
  • Does PTP work at last? I have never seen it work on dozens of android phones as far back as I can remember.
  • If you unlock developers options, you can set it to what you want by default, under networking, select USB configuration. You unlock developers options by taking build number in about phone. Charging, MTP, PTP, Ether net, audio source, MIDI  Posted via the Android Central App
  • And it reverts back to charge only the next time you plug it in.
  • On my N7 2013 it reverts the status bar message to "charge only" but still connects to the PC with MTP anyway as long as that's what is set in developer options. Only the first time did I have to actually choose the MTP mode with the notification and ever since it keeps connecting as MTP without issue, even persisting through reboots.
  • Definitely only works the one time for me. Need to go into Developer options/Networking/Select USB configuration and select MTP. After reboot Nexus 7 appears on PC but internal storage is not displayed. Going into Developer options/Networking/Select USB configuration MTP is shown as the option but internal storage can only be accessed by pressing Select USB configuration, MTP is shown as being selected but this option MUST be selected again to enable access to internal storage. CRAZY!! Wouldn't it be more sensible for this option be in Settings/Storage & USB?
  • What's audio source mean? Posted from my Nexus 6/Nexus 7 2013/Surface Pro 3
  • I had to look it up, cuz no idea that was even an option
    API hooks for associating audio and input devices. This is particularly useful if your app allows users to start a voice search from a game controller or remote control connected to Android TV
  • Thank ya kindly. Posted from my Nexus 6/Nexus 7 2013/Surface Pro 3
  • Thanks a ton, FisherOfMen58! I couldn't follow Jerry's instructions to "go into your notifications and tap the USB Connections entry." Nowhere could I find this, but your instructions got me into developer mode and I was able to change the USB connection options to MTP. I was able to see my N5 file system on my PC with no problems after that. Thanks again!
  • Is usb otg built into android 6.0? Posted via the Android Central App
  • Yes.
  • I connected my pendrives by otg cable but the message is unsupported drive and the message is to format it. Please help.
  • There's actually a very very good reason for keeping phones from making data connections by default: viruses. USB device hacking/viruses have grown tremendously over the past couple years. By ensuring the phone does not make a data connection when plugged into anything, you don't need to worry about whether the airport charging terminal you're using has some sketchy phone hacking module installed on it, for instance. You also don't have to worry about plugging your phone into a PC and accidentally turning your phone into a carrier for PC-based viruses.
  • Extremely good point Posted via the Android Central App
  • Probably a dumb question on my part. If you have a lock screen/pattern/pin on your phone and you plug it in to a PC with one of the data transfers as default..can you still view the data? Because that would be a bad situation to have if your phones gets lost or stolen.
  • I have to admit, CSI Cyber had an episode related to this, and it did make me wonder just how feasible it could be. Possible, yes. Likely? Unsure...... I guess with card skimmers and such, I really shouldn't be surprised this kind of attack could happen more than I'd think Posted via the Android Central App
  • Viruses have been infecting portable hard drives/usb drives for over a decade. When your phone is in MTP mode (which used to be the default), it's acting as such a drive, and can be a carrier for viruses. So yes, it's not only feasible, it's been happening for many years.
  • Very well stated. Couldn't have said it better than anyone else. Posted via the Android Central App From my Blackberry Priv where I am out of toilet paper
  • I think the option is also a good thing. But the 'bug' about it not "Sticking" on MTP needs to be fixed.
  • It is really good to disable MTP by default, but why not provide a setting for us to modify it? Some people (like me) would prefer using MTP by default, I even don't have a lock screen with my phone, everything I prefer is simple and fast.
  • It's a point well-taken - but the better solution is educating people not to plug thing in where they shouldn't (there's an analogy there...), not forcing an action which causes plug and play actions (like Android Auto) to effectively break.
  • Android Auto...EXACTLY why Google needs to add an option to remember a specific device choice once you plug it in the first time! I can understand the protection from PC connections/virus, etc... but this has been annoying the **** out of me since upgrading form my Lollipop S5 to the S7 Edge a week ago. What used to be plug and play in my truck is now a 3 step process. Fingerprint scan, slide down from top, find USB connection option amongst all the other notifications, then select MTP. It shouldn't be that way Google! I'm hoping after a long list of complaints from all the new Android Auto enabled cars that are coming to market, that they 'll add this option at least for Android auto. But make it quick though, I don't feel like rooting just for this simple "protect me from myself " feature...
  • This makes perfect sense to me. So many people that I know use their work PC to charge their devices. It's common for office IT policy to not allow any unapproved or un-virus scanned mass storage to be connected (for obvious reasons). Defaulting to power only reduces the risk of unwanted files moving either way, and so makes Android devices more appealing to the business sector.
  • Awesome
  • Should identify the computer and do it once for each it sees (assuming it can do so)
  • That's the one thing iOS does that Android should do, when you plug an iPhone in to a computer for the first time it asks if you want to "trust this computer" Moto G 3rd Gen 2015 with only 1GB of RAM
    Nexus 7 2013
  • My G4 does the same thing It tells me if I just want to charge it or mount it as an MTP or PTP.
  • I actually think this is a *GOOD* thing. OK, you have to tap the phone/tablet a bit more to get connectivity. But this has the advantage tht if you connect the device to a USB port in a public device (airport, internet cafe, etc.), you *KNOW that nothing will get out of your phone without your prior explicit authorization. After seeing what can happen when you connect your phone on someone else's port, I actually went and got those USB connectors that you plug in a USB port, and in which you connect your phone, and this connector will only carry power, nothing else. So a few swipe/touch to protect my phone from others' trojans, malware, and other bad stuff out there ? SURE !!!!
  • Thank you. I finally get why PTP is there when MTP seemed to be able to do the same thing. SMH. Doesn't bother me about an extra step, Google's settings have always been all over the place on different devices anyway. Maybe that's what they're aiming to improve with newer OS. One can only hope.
  • Its about time Google or Apple allow Android phones to be mounted on Macs like any other USB drive. I don't understand why it's so difficult given both systems are unix based.
  • Yes! I had an HTC G2 that did, every phone after that has required Android File Transfer which is annoying.
  • Me too, except I'm just now studying how to get a replaement working before i swicth. I am no liking the process and failrly unimpssed with the new version, for all it features, some of which are excellent.
    My current problem, an obscene form of this one, I think I'll report on a new thread.
  • i want to connect my nexus 5 (marshmallow) to pc, then some files data is missing, and not read in my pc, only some files (image especially). why? this happen a week ago.
    thanks so much :))
  • Hi. Did you find a solution to this? Are we the only two people facing this problem!! Can't seem to find a solution. There are entire folders which the PC is not reading
  • I'm also facing same prob. when i connect my phone to PC i can see the options charging oly, MTP,PTP,MIDI.
    when ever i select MTP i can see both internal storage and SD card Storage. I can access to the files in Internal Storage but i cant access to the SD card storage. it shows empty.
  • Hi,
    I am using nexus 5.
    i have noticed 1 thing when i see my free storage in phone setting its show free space 1.15GB and when i connect it to computer its show free space 685mb, did any know the reason behind this free space difference? what should i do?
  • Why?
    Is this as stupid as it seems? Please give me a good reason why we're not doing both at the same time? *just to clarify, having to select 'charging' or 'file transfer' as theUSB mode is stupid.
  • I’ve made a small app to automate the MTP enabling…
    Have a look at xda here:
  • Thank you for the help.
  • OMG Now I have to make this choice EVERY SINGLE TIME I PLUG IN MY PHONE? This is SO STUPID! How could anyone think it is a good idea to remove a default selection and force you to make the same selection every single time? I am sure the Android fan boys will say USB is old school and we should all be using the cloud or WiFi. But consider this, I use my phone to take pictures of test setups at work all the time and need to plug my phone in to transfer the pictures to my computer. NO I can not transfer them by WiFi because only phones issued by the company are allowed to use the corporate WiFi.........
  • Well !! Sir , my USB card is not shown in my Windows laptop when i am connecting it. Tried many ways but all went in vain .. Anything i can do to fix it ???
  • I'm facing the prob. when i connect my phone to PC i can see the options charging oly, MTP,PTP,MIDI.
    when ever i select MTP i can see both internal storage and SD card Storage. I can access to the files in Internal Storage but i cant access to the SD card storage. it shows empty. Could somebody pls fix it or solution to it.
  • This solution doesn't even exist for me. I have the Nexus 6. AT&T pushed out Marshmallow yesterday evening. I "upgraded". What a mistake! Now I have no ability to access files via USB. I see no "USB Connection" menu item to tap, no dialog via Notifications or anywhere else that allows me to change anything related to file access/charging/transfer. This is extremely disappointing, and it just begs the question -- why stay with this OS when it's not ready for prime time? I don't blame AT&T. Google obviously didn't care enough to support its product by ensuring that AT&T vetted and rolled it out properly.
  • Ditto.... have 6.0.1 ... no USB connectivity option at all anywhere on the phone... grumble....
  • Same here. There's got to be a setting somewhere though.
  • Hey thanx. It's very helpful....
  • "What you'll need to do is go into your notifications, and tap the USB connection entry." -- This doesn't happen. I am getting NO notification saying "USB connection". I used to but not after the update. The only indication I get is the battery icon show a lightening bolt on it showing the battery is charging. That's it. In Developers options, I see the USB connection is set to "Charging only" and when I try to change to MTP if goes back to Charging only. Any other bright ideas? Such as, how do I roll it back to Lollipop and get off the POS OS?
  • Thank you for this article. Spent an hour trying to figure out why my S6 Edge fired up Android Auto every time right on time, while my brand new S7 Edge didn't want to play. This is obnoxious. The whole point of "plug and play" features like Android Auto is that you don't need to DO anything but plug it in. Hopefully an oversight.
  • HTC One M8, enabled the developer menu and de-selected "always charge": but was stills stuck in charge mode. After many attempts at various solutions, I then plugged the phone directly into the back of the computer instead of my powered hub and was able to make file transfers. Did not have this problem with lollipop. Apparently the phone senses the power hub and always tries to charge. And yes, powered hub was connected to the computer.
  • Tried so many options, Had to dig internet for 2 hours and nothing worked.
    This one worked out just fine:) Hope would do the same for you
    reddit DOT com/r/Android/comments/3nnkaa/cant_access_android_device_internal_storage_from/
  • Any update to making this default? I tether my phone every day, twice a day and the connection is always going in and out, so selecting this drives me crazy.
  • My problem is similar to these awful thing, but it seems to be a new form.
    I have a new out of the box NEXUS 5X, shipped with Marshmallow installed, and seeming to be up to date, since that damned incessat notification offers no update other than going to 7.0!! i REEELY really want THAT untested thing amirite? So, I finalldug out the information about having to inatall the interface on the Mac, which I did. This now works fine on my OLD phone, version 2.
    So I went to the Marsh, and for a moment, as recalli, it worksed.
    So yesterday for some reason I installed its zowie Exlporer.
    Now the Storage and USB config page shows the the storage and nothing else.
    What a pity that all the info about these phones indicates no way at all to report nasty bugs. Or does it? Does anyone have a secret contact?
    I went to the Help for the page it does have, and told the Help writer that the page sidn't help me with how to run USB ! I mean, if thousends of people did this (!) somebody might notice.
    What a pity my version 2 phone won't physically last forever.
  • I chatted with Samsung tech support in Australia today. They have a fix for this problem but we don't. One somewhat helpful hint however is dialing *#0808# on your phone. This brings up a system dialog box. I selected the MTP + ADB and saved. Then when I plugged in my phone USB it opened a new window on the computer that listed the Samsung device. I still have to select the Allow option on the phone but the window reminds me that I need to switch to a screen where I can see that notification.
    With the phone locked I couldn't see the notification and thought I was crazy cause nothing happened on the computer. Now, I know I'm not crazy (when it comes to this anyway)