Techniques are presented to detect word line failures (such as word line to word line shorts, control gate to substrate shorts, broken word lines, and so on) in non-volatile memory arrays. A first simultaneous read of multiple word lines is performed, followed by a second simultaneous read of the same word lines, where the read conditions of the two reads are shifted by a margin. For example, one of the read could use a standard read voltage on the word lines, while the other read could shift these levels slightly higher. The results of the two reads can then be compared on a bit line by bit line basis, XOR-ing the results to determine is the set of word lines may include any defective members.