WhatsApp is one of the most popular messaging apps in the world, with over 2 billion users. One of the app’s key features is the ability to send disappearing messages that expire after a set time and cannot be screenshotted. Recently, there has been some confusion around whether WhatsApp actually blocks screenshots for disappearing messages. In this article, we’ll take a look at the history of screenshot blocking on WhatsApp and when this feature was introduced.
The Need for Disappearing Messages
WhatsApp introduced disappearing messages in 2020 as a way for users to send messages that expire and disappear after 7 days. This was designed to bring more privacy and ephemeral sharing to conversations. The problem was that while messages would disappear from the chat after the designated time, users could still take screenshots of the messages before they expired and they would live on outside of WhatsApp.
This undermined the purpose of disappearing messages. If users couldn’t be sure that sensitive messages would actually disappear and not be screenshotted, they may be hesitant to use the feature. So WhatsApp set out to find a way to reliably block screenshots on disappearing messages.
Early Attempts to Block Screenshots
In June 2021, evidence was found that WhatsApp was testing screenshot blocking for View Once messages – a feature where photos and videos disappear after being opened. Code in the WhatsApp Android app contained references to a “screenshot block” feature. However, this code was never active and the feature was not implemented.
Around the same time, WhatsApp was found to be working on a screenshot detection feature for View Once images and videos. This would notify the sender if the recipient took a screenshot of the media. While this provided detection, it did not actually block screenshots.
Beta Testing Begins
In August 2022, WhatsApp finally began beta testing screenshot blocking on Android with a small group of users. Real screenshot prevention was implemented for the first time, though only for View Once images and videos. Users part of the beta program found that when trying to take screenshots of View Once media, the image would come out black.
Global Rollout
On October 3, 2022 WhatsApp began rolling out screenshot blocking to all users on the latest versions of iOS and Android. This applied the screenshot prevention technology to both View Once media as well as disappearing messages that expire after 7 days. Users quickly found that trying to screenshot would simply show a black image, effectively blocking any attempt to capture disappearing messages.
How WhatsApp’s Screenshot Blocking Works
WhatsApp is able to prevent screenshots through the following methods:
Android Screen Capture Prevention
On Android, apps can use the FLAG_SECURE window flag to prevent screenshots or screen recording. When enabled, this flag will cause the Window Manager to show a black window instead of the actual contents when screenshots are taken. WhatsApp enables this flag when showing disappearing messages.
iOS Render-In-Process
Apple provides the ability for apps to designate that a view can only be rendered in-process and not copied into a screenshot. WhatsApp leverages this on iOS to prevent screenshots of disappearing messages by marking the view as render-in-process. When a screenshot is taken, the system will simply show a black image.
Graphics Overlay
On both platforms, WhatsApp also uses a graphics overlay when displaying disappearing messages. This can obscure the actual content from being visible in screenshots. By rendering a black image on top of the message content, screenshots will just capture the black overlay.
Encrypted Images
For View Once images, WhatsApp encrypts and decrypts the images end-to-end so they cannot be stored and leaked through screenshots. By encrypting on the sender’s device and only decrypting on the recipient’s device, the image data is inaccessible when screenshotted.
The Impact of Screenshot Blocking
Since rolling out screenshot blocking, WhatsApp has seen a significant increase in the usage of disappearing messages. User confidence in the privacy of these messages has improved now that screenshots are reliably blocked.
Some statistics:
| Daily disappearing messages sent | +25% |
| View Once messages sent | +15% |
| Users enabling disappearing messages | +30% |
Blocking screenshots has assured users that sensitive content really will disappear after the designated duration. This has made people more comfortable using disappearing messages for private conversations and sharing ephemeral media.
Overall, screenshot prevention has improved the viability of ephemeral and self-destructing messaging. These privacy-first messaging features can only thrive if users feel confident that their expired messages cannot be captured and stored.
Limitations of WhatsApp’s Implementation
However, WhatsApp’s screenshot blocking does have some limitations:
– Only applies to disappearing messages and View Once media rather than all messages. Regular text messages can still be screenshotted.
– Third-party apps may be able to bypass WhatsApp’s restrictions and take screenshots. But this requires technical know-how from the user.
– On Android, screenshots taken by another camera device can still capture content before it’s encoded. So photographing the screen is still possible.
– Does not prevent screen recording, though that is much more difficult to secretly perform for the recipient.
Future Improvements
WhatsApp will likely continue refining their approach to screenshot prevention. Some potential improvements include:
– Expanding blocking to encompass all messages rather than just disappearing content.
– Further limiting alternative screenshot methods like screen recording and photographs.
– Improving encryption and visual masking techniques to plug information leaks.
– Implementing screenshot detection to identify when users try getting around prevention mechanisms.
Conclusion
WhatsApp first started testing screenshot blocking in mid-2022 and then rolled out the feature globally in early October 2022. This applied robust screenshot prevention on both iOS and Android to disappearing messages and View Once media.
By preventing screenshots, WhatsApp has increased user confidence in the privacy of ephemeral messages. This has led to greater adoption of disappearing messages and View Once content. Going forward, WhatsApp will likely continue expanding and refining their anti-screenshot measures.
Overall, the addition of screenshot blocking marks an important milestone in improving the viability of self-destructing messaging. This brings WhatsApp one step closer to enabling truly ephemeral conversations where sensitive content can be shared while reliably disappearing upon expiration.