• AirDrop-style application that’s cross-platform.
• Open-source code base and multilingual.
• File send and receive on Mac, Windows, Linux, iOS, Fire OS, and Android.

Since 2011, Apple users have been able to share files between devices using AirDrop. Whether it’s a picture taken on an iPhone, or an office document from a desktop Mac, files can be exchanged simply and easily, with the facility listed in the Share submenu in users’ mobile apps and accessible from the Apple Finder.

Of course, the facility was implemented as Apple-only, but the idea soon caught on. The first app in the same vein for Android was developed by Samsung and called Nearby Share, which was later integrated into Quick Share by Google. That’s the app now available for users of both Android (with Google Play Services) and ChromeOS.

Apps like AirDrop and QuickShare have brought the exchange of files and other information – like addresses or contact details – to a generation of users now accustomed to the convenience. But all variations existing at present (there are several similar, third-party applications) have downsides in the way they operate.

• The implementations readily available tend to favour one or just a few architectures. Android users can’t easily exchange data with Apple users, for example, unless both parties are able and willing to set up supporting services, like shared cloud storage that acts as an intermediary.
• The issue of proprietary, closed software to send and receive information is a potential cybersecurity and privacy issue. The first iterations of AirDrop had the ability to send information to anyone on the same network turned on by default, a setting that was quickly limited by Apple to a ten minute window. Apple made the change after pressure from the Chinese government who were wary of users mass-disseminating controversial information.
• The reliance on cloud services of some of the available apps of this type means that purely local file exchange (that is, with no internet connection) can be impossible.

LocalSend is an open-source project that aims to address all the above caveats. The app runs on Amazon Fire OS, Android, and iOS devices, and software for PCs is available for the Windows, Mac, and Linux operating systems.

Once the software is installed, devices identify themselves with a random name or numeric ‘hashtags’ (the device names are editable), and communication between parties is kept entirely local. Each device effectively acts as a small-footprint, secure, headless web server, one that’s capable of discovering and interacting with other instances of LocalSend that advertise on the same network, via right-click or Share menu.

We tested LocalSend between Android, iOS, Windows, and Linux desktops, and were impressed with the speed of discovery and data transmission rates. The user interface, created in the cross-platform Flutter framework, looks pretty much identical on every platform, so users will be able to navigate the software regardless of what device they happen to be using. Integration into the base operating system adds LocalSend into the list of ways to share files quickly.

The developers advise downloading the app from a platform’s known app stores (Play Store or F-Droid on Android, Winget for Windows, or the Apple App Store, for example), although if the user is willing to be responsible for downloading future updates, there are static installers and familiar containerised instances like Flatpak and AppImage, plus .dmg and .exe binaries for manual download and installation.

The software’s security settings (such as the off-by-default sending or receiving to all devices) are set sensibly on first run. And the source code for the application (written in Dart) is open for examination, so organisations can check exactly how the software works and assess its safety as part of overall security policies.

Unlike proprietary versions of this type of software, where any bugs or security holes rely on an internal devolopment and security teams’ vigilance, the public nature of the software means it’s much more likely that issues are spotted and fixed.

Theoretically, like every open-source software, LocalSend’s cybersecurity team comprises of every security specialist on the internet capable of reading code! The same release model also gives users a degree of assurance as to the project’s longevity – even if the original developers stop working on LocalSend, others are free to fork and continue the project’s development and upkeep.

The application may be of particular use where older hardware is still in production. Compatibility goes back to Android 5.0, iOS 12.0, macOS 10.11, and Windows 10. LocalSend is released under an Apache 2.0 licence with 50+ translations available, and the project is actively accepting pull requests. Those finding LocalSend useful are urged to either contribute to the code base, file bugs or issues, or donate via GitHub or Ko-fi.