Transferring photos and other files between nearby smartphones should be simple, but it’s not. There are a variety of different ways you can do this, and which is best depends on which types of smartphones you’re transferring files between.

This is particularly complicated because so many of these methods aren’t interoperable. Android, iPhone, and Windows Phone all have their own ways to send files and they don’t like talking to each other.

NFC

Any Android device running Android 4.1 or later with an NFC chip inside it can send files via NFC using Android Beam. Just open the photo or other file, press the phones back to back, and you’ll be prompted to wirelessly “beam” the file to the other phone.

This works great for quickly sending photos, but it can’t send every type of file. It’s also very limited. iPhones don’t have integrated NFC hardware, so they can’t participate. Windows Phone and BlackBerry devices do have NFC hardware, but Android Beam can’t send files with them — it’s Android or nothing.

Windows Phone devices can send files between each other with NFC, so you’d be in luck if you managed to find someone else with a Windows Phone.

Bluetooth File Transfers

Smartphones generally have integrated Bluetooth hardware, and Bluetooth can be used to wirelessly transfer files between nearby devices. This seems like a solution that would work across all smartphone platforms. However, while Android supports Bluetooth file transfers, Apple’s iPhone does not.

Luckily, Windows Phone 8 and BlackBerry both support Bluetooth file transfers, so this can theoretically work across all modern smartphone platforms, excluding iOS and devices that haven’t been updated from Windows Phone 7.

On Android, you’ll need to open the file you want to share — for example, view the photo in the Gallery app — tap the share button, and then select the Bluetooth option. You’ll be prompted to set up the Bluetooth pairing between the two devices.

Share Over Dropbox or Another Service

Since hardware-based methods are so incompatible across devices — nothing so far is compatible with an iPhone if only one of you has an iPhone — you’ll probably want to rely on some sort of online service.

There’s a good chance one or both of you already use Dropbox. If you uploaded the file to your Dropbox app — on Android, you can even have photos you take automatically upload to your Dropbox account — you can then share a link to the file so the other person can download it directly from your Dropbox account.

Email the File

What’s the only way to wirelessly send a file to someone else’s smartphone and have them receive it without needing a specialized app, no matter what smartphone they’re using? There should be a standard that makes this easy, but there isn’t — so the answer to the question is email. Emailing a file is the only way you can share a file with anyone else using any smartphone, no third-party apps needed.

Just fire up the email app on your phone, attach the file, and send it to the other person’s email address — they’ll get the file in the email inbox on their phone.

It’s a shame that, after all the sophisticated software we’ve developed, email is still the most reliable way of sending files.

AirDrop

Apple may refuse to support standards like NFC and Bluetooth file transfers, but they’re working on their own local-area file transfer solution for their upcoming iOS 7.

The AirDrop feature will show you other iPhones in your nearby area and allow you to share files and other data to them. Unfortunately, this is an iPhone-only feature, so iPhones will still be cut off from Android, Windows Phone, Blackberry, and everyone else when it comes to local wireless file transfers.

Of course, there is a wide variety of other options for transferring files. You’ll find many third-party apps that give you ways to wirelessly transfer files in every smartphone platform’s app store, but you’ll generally need to be running the same app as the other person if you go this route.

None of the above methods is particularly ideal for large files — for example, if you want to copy your music collection to a nearby phone. In situations like these, you may want to just connect your phone to a computer, copy the files to the computer, and then connect the other person’s phone to the computer and copy the files onto the other phone.