Let me show you the WeChat version first. It is 6.3.
What will happen to WeChat deleted chat messages? Take a look at "Blocks containing deleted data" and those deleted messages were wiped.
What about WhatsApp? The version is 2.12.317.
Fortunately those deleted chat messages were not wiped...
So far we know LINE and WeChat will wipe deledted chat messages, no matter what kind of forensic tools you use, it‘s impossible to recover deleted chat messages because those deleted chat messages being wiped.
WeChat 6.3 wipe deleted chat messages as well as LINE 5.3 and above
原文：http://www.cnblogs.com/pieces0310/p/4890611.html