Difference between 生前 and 死前 Literally, 死前 means before death while 生前 means before life. They seem to bear the opposite meaning. However, in most cases, they actually mean the same thing, i.e., when someone was still alive. What's more, in my experience, 生前 is being used more often than 死前. Any difference between them and when to use which?
Yes, you are quite right that they both mean when someone was still alive. However, there is a clear distinction on the usage of the two words. 生前 is almost always used when someone is discussing about the life of a deceased. Example: 


  He did a lot of charity work when he was alive. 他生前做了很多善事。


死前, or more properly 临死之前, is almost always used when someone is discussing about a person prior to his death. Example:


  What did he said to you before he die? 他临死之前跟你说了什么？