[Android Central Question]

The update isn't compatible with my device galaxy tab s3

[Rukbat]

First, does WhatsApp work? If it does, don't worry about updating it. (Don't "fix" what's not broken.)

Second, the device is over 4 years old, so you're going to find that with a lot of apps. Backward compatibility isn't something you can look for in most software. (Microsoft does it - to their detriment. Windows 10 isn't actually "current" because of that.] Apple never did - nothing written for the 128K Mac can run on today's iOS. Programs written for even older PCs can still run under Windows 10, many times.)