Just so, is XRay in Minecraft cheating?
In Minecraft, one of the hardest things about it can be finding the ores and cave systems you need. If you don't mind playing the game in a way that is technically 'cheating,' using an X-Ray is a great way to track ores down, from the rarest to the most common.
Beside above, is XRay Minecraft illegal? The simple answer is no, you cannot be banned.
Similarly one may ask, can Minecraft XRay be detected?
its impossible to detect somebody with x-ray unless they confess or they find a well hidden chest or storage area, though that could be purely coincidental.
Is Xray in singleplayer cheating?
It's not cheating (on singleplayer) unless you make it against your OWN PERSONAL RULES to use one.