The argument has long been that you need to give up simplicity and convenience for security. This has especially been seen as the case with mobile messaging, in which consumer friendly apps siphon off your personal information to monetize it, whereas security apps tend to lack pleasing (or usable) user interfaces. WhatsApp proves this thinking wrong. This excellent iPhone app now offers end-to-end encryption for every user on every platform, along with group texting and voice chat, wrapped in a simple and nicely designed (if a slightly stale) package. Another big point in the service's favor is that it boasts an enormous user base, though North American readers might struggle to find their friends on it.
The popularity of WhatsApp really cannot be understated: The service now tops 800 million users and boasts apps for iOS, Android, BlackBerry, and Windows Phone, along with more rarified platforms like Symbian. For this review, I used an iPhone 6 and also tested to see how it worked cross-platform by messaging a Nexus 5x. WhatsApp used to be free for one year and 99 cents for each following year, but the service is now free for everyone, forever.
No Account Necessary
Facebook Messenger and other mobile messengers require that you create or log in to an account the first time you fire up the app. Not so with WhatsApp. Instead, you type in your phone number, which WhatsApp verifies with a text message. The service then offers to scour your address book for phone numbers from other users, and automatically adds them as friends. This isn't exactly optional; in my testing, I found that if contacts weren't in my phone's address book, they weren't available in WhatsApp.
One thing to note is that the success of a mobile chat platform largely depends on how many people already use it. Although WhatsApp has hundreds of millions of users, many of them are outside the U.S. In fact, I only found a handful of users already on the service. Google Hangouts and Facebook Messenger are far more ubiquitous in the states. If you want to message U.S. friends, you may need to recruit them to the service.
Though you won't have to create an account with WhatsApp, the iPhone app offers to back up your media and messages on iCloud. If you migrate between devices or reinstall the app, WhatsApp will conveniently prompt you to Restore Chat History. I also noticed that when reinstalling the app, I wasn't prompted to confirm my device again. Convenient!
This no-account setup keeps WhatsApp light and easy to use. It's also an inherent security measure, since someone would have to spoof your phone number (or steal your phone) to impersonate you. I've seen other messaging platforms, such as the security centric Telegram Messenger, do the same thing. But it means that your WhatsApping is limited to a single device. You can enroll as many phones as you want, but your friends will need separate numbers for each listed in their address books. Facebook Messenger, on the other hand, pushes all your messages among all your devices (and the Web) for maximum visibility. It also means you can't just give an account to casual acquaintances—they will have your actual phone number. Luckily, WhatsApp offers a Blocked Caller list.
Not much has changed aesthetically since I looked at WhatsApp two years ago, which is pretty disappointing. There's nothing wrong with WhatsApp's design per se: Messages still appear in threaded conversations by participant, and a navbar across the bottom lets you quickly access the app's features. You can still change the background of your chats. It's entirely functional and eminently easy to use.
But after so many years, WhatsApp is starting to feel a little stale. Facebook Messenger has a much cleaner, engaging design that I prefer. I spend too much time tapping through menus to get to critical features in WhatsApp. Also, the Contacts section is misleading, since it makes no distinction between who's enrolled in WhatsApp and who isn't; it just shows everyone I've saved to the Contacts app. The Favorites section shows your friends on the service, but you'll want to prune this list, lest it become too long to be useful.
The core of WhatsApp is sending person-to-person messages, but you can also send group messages to a maximum of 10 participants. These work as you'd expect: Messages sent to the group are filed in a special thread you can name, separate from other conversations. Participants can easily unsubscribe and tweak their notifications, so no one has to feel spammed with group messages.
Alternatively, you can create a broadcast message. This functions a little like a blind carbon-copy. If you send a broadcast message to Alice, Bob, and Condoleezza, it appears as if you sent the message directly to them. Broadcast messages appear threaded in recipients' existing conversations with you, not in a separate thread as group messages do. It's a bit confusing, but nevertheless a powerful communication tool.
You can send more than text messages, too: images, audio clips, video clips (up to 16MB), and emojis are also options. You can attach files, locations, and contact cards, too. Once, all of these were features hard to find outside WhatsApp, but they've since become commonplace. Noticeably missing are stickers, which have been adopted even by security-first services like Telegram and are (in my mind) the killer feature of Facebook Messenger.
WhatsApp isn't just about texting. It also supports voice calls from within the app. Calls made through WhatsApp launch a unique call screen that is similar to, but distinct, from Apple's built-in phone app. My test call connected quickly, and sound quality was quite crisp, if a bit trebly. As with Skype, you can use WhatsApp to send messages and media during voice calls. I really like this feature. But I am disappointed that you cannot add more participants, meaning calls are strictly person-to-person.
WhatsApp began rolling out voice calls slowly but sometimes showed a phone icon even if the feature hadn't been activated on your device. Instead of calling through WhatsApp, the call was placed using your existing voice plan and the built-in phone app. A cryptic error message was my only indication that my call wasn't being routed through WhatsApp's service. I last saw this problem nearly a year ago, and it has hopefully been sorted out for all users now.
A year after voice launched, WhatsApp still doesn't support live video chatting, a feature embraced by many modern messengers, including Skype, Google Hangouts, the ephemeral Snapchat, and Apple's FaceTime. Snapchat, it should be noted, recently overhauled their voice, video, and text chatting interfaces and the experience is now vastly improved.
It took a while but you can now access your WhatsApp account through the Web—kind of. The feature first rolled out for Android about a year ago and I assumed it would never make it to iPhone. To use it, you navigate to a special website and scan the QR code on the screen with a special reader in the WhatsApp Settings menu. This links your phone to the website, and you can send and receive messages from your computer.
Note that you are simply accessing the same account through your computer. We were surprised to discover that you can continue to use the desktop app from your Manhattan office even when your phone is, for example, in Queens. However, if your phone loses connectivity, you won't be able to use the desktop app. WhatsApp advises that you use a Wi-Fi connection when connecting to the desktop app to avoid burning through your data plan.
Early in its life, WhatsApp was synonymous with two things: overseas ubiquity and a poor security track record. WhatsApp's developers had to pivot after users complained about how the app hoovered up their entire address book, a practice the app has since abandoned. The popularity of WhatsApp has also made it a target for scammers and hackers, like the individuals behind a service that sells stolen WhatsApp chatlogs.
That changed for Android users in November 2014 when WhatsApp announced that it had partnered with WhisperSystems, the developers behind Signal, the excellent secure texting and chatting for iPhone and Android. The two make a great pair, combining WhisperSystem's extensive work on their open-source encryption protocol and WhatsApp's enormous international user base. The practical upshot is that, according to WhisperSystems, "billions of encrypted messages are being exchanged daily."
This same security is now available to all WhatsApp users, regardless of platform. Best of all, messages sent between platforms (from Android to iPhone, for example) are encrypted. All WhatsApp messages can now only be read by their intended recipients. No one, not even WhatsApp, can decrypt them. And not just messages: every photo, attachment, and even group message is secured end-to-end. The company manages to do this by letting each device manage its own encryption keys. If the FBI asked WhatsApp to hand over someone's chat logs, the most they would get would be unreadable mush.
WhatsApp also strives for perfect forward encryption and periodically changes the keys used to encrypt information. This means that if one message is successfully decrypted, that message's key couldn't be used to decrypt all previous or future messages. Editors' Choice Wickr also employs a perfect-forward strategy and actually uses a different key for each and every message.
Unfortunately, I had a mixed experience with encrypted chatting on iPhone. By default, the app doesn't tell you that your messages are being secured, though you can change this. Instead, you tap on a user's name and see a padlock on the following screen. But I encountered a situation where WhatsApp told me that my messages were encrypted end to end, but the app told my messages' recipient that his connection was not encrypted. Were my messages secure or not? There's no way to tell, and it doesn't inspire complete confidence in WhatsApp's security strategy. It's unclear how end-to-end encryption works with WhatsApps desktop integration, and I have reached out to WhatsApp's developers for clarification.
What's Next for WhatsApp?
WhatsApp is the biggest, most popular mobile chat service there is, though you might not know that in the U.S. And the company deserves a lot of credit for doubling down on real, solid security. WhisperSystems is the perfect partner, and a mind-boggling number of people just got protection from hackers, stalkers, and government surveillance. With just the flick of a switch, WhatsApp has proved that you don't need to give up convenience for security.
It's an impressive achievement, and has earned WhatsApp an enormous amount of credit in my eyes. But it's important to remember that Apple's Messages app nearly removes the need for an SMS plan (provided you only exchange messages with other iPhone owners), is tightly integrated with OS X, offers video calling with FaceTime, and is also encrypted end-to-end. And while WhatsApp is very easy to use, it's starting to look a little dated on iOS and could use a facelift. That, and stickers.
Those minor points aside, this really is a great day for privacy and security, worldwide. If you've never used WhatsApp, now is a good time to try it out. But I still prefer the look and ubiquity of Facebook Messenger, and turn to Signal or Editors' Choice winners Wickr and Telegram for sending secure messages.