There’s really no way to test this without dunking the phone in water. If the seals are intact it will survive but if they’re shot, you can kiss your phone goodbye. Since there’s an app for almost everything these days, what if there was one that could tell you if the device was still water resistant?
Yes, there is an app for that
The Water Resistance Tester app claims to do just that. Developed by Ray W, the app relies on data from the barometric pressure sensor found in most devices to basically make a prediction about the state of water resistance.
They way it works is that the app measures pressure levels through the barometric sensor. When you launch the app, it tells you to leave your phone alone for a minute or two as the sensor is calibrated to measure the baseline. You’re then instructed to firmly press on the screen at two points with both thumbs. The app measures the pressure difference to let you know if the device appears to be water resistance.
It’s a solid proof of concept. You can test it by removing the SIM card tray on a device that was previously identified as water resistant. The app will throw up a negative result when the tray is popped out.
The app can be a bit temperamental. It gave us a positive and negative result in successive tests on the same Galaxy S21 Ultra. Not surprising, since the developer himself doesn’t provide any guarantees on the accuracy of the results. Even if positive results are all you get from the app, I’d still think twice before exposing the device to water for no good reason.
Water Resistance Tester is available as a free download from the Play Store. It has in-app ads that you can remove for a $0.99 donation.