The Sharingan's abilities consist of two parts: the "Eye of Insight" (洞察眼, Dōsatsugan) and the "Eye of Hypnotism" (催眠眼, Saimingan)
•"Eye of Insight" (洞察眼, Dōsatsugan) - First, the user must perfectly mimic every move their opponent makes and possibly their thoughts and words through careful observation. Then, they suggest an action to the opponent such as hand seals for a technique that the opponent and Sharingan user already know and copy that. With these things done, the user can complete the action even before the opponent does, possibly using the Sharingan's genjutsu to confuse or delay them. As with other genjutsu, genjutsu cast by the Sharingan are capable of putting an opponent to sleep, inducing paralysis, replaying memories to someone else, or creating various illusions to deceive someone. The potency of the Sharingan's illusion is dependent on the user's knowledge and skill with implementing genjutsu.
•"Eye of Hypnotism" (催眠眼, Saimingan) - The hypnotic ability coupled with the other aspects of the Sharingan, can make the user appear as if they can "see the future".
•Sharingan(3 Tomoe) - First ability allows him to see the flow of chakra running through a person, and it also allows him to see if he is under genjutsu because the person's chakra flow would be irregular. His second ability gives him an incredible clarity of perception, allowing him to easily recognize genjutsu and different forms of chakra, though not to the same extent as the Byakugan. This also allows him to pick up on subtle details, enabling him to read lip movements or mimic something like pencil movements. As his Sharingan evolved by gaining more tomoe seals, this ability extends to being able to track fast-moving objects before finally giving some amount of predictive capabilities to the user, allowing him to see the image of an attacker’s next move from the slightest muscle tension in their body and counter or dodge without any wasted movement. However, even though he may be able to see an attack or know it is coming, their body may not always have time to react. The third ability granted allows him to memorize any technique that he witnesses, apart from other kekkei genkai techniques. He can memorize ninjutsu, genjutsu, and taijutsu with near perfect accuracy, allowing him user to use the techniques as their own, or even modify them to create his own new techniques. The Sharingan cannot reproduce techniques dependent on other factors, such as summons that the user has not signed a contract with.
The Mangekyō Sharingan grants the user access to other powerful techniques. The Mangekyō Sharingan is distinguished from a normal Sharingan by its appearance, which changes the form of the tomoe seal. Unlike the Sharingan, the appearance of the Mangekyō Sharingan differs from user to user. The Mangekyō Sharingan is acquired through the death of the person closest to the Sharingan user. To expedite this occurrence, Uchiha throughout history have killed their closest friends in order to meet this criteria. To obtain the Mangekyō Sharingan, one must feel the emotion of losing a friend or family, as merely killing them or watching them die will not activate it. Over time, use of the Mangekyō Sharingan's techniques deteriorates the user's eyesight to the point of blindness. Only by taking and transplanting the eyes of another Uchiha clan member can the vision be restored, a process that results in the creation of an "Eternal" Mangekyō Sharingan (永遠の万華鏡写輪眼, Eien no Mangekyō Sharingan). The tighter the blood ties are between the "donor" and the receiver, the better it is for compatibility, siblings for example. Not only does this process permanently restore one's eyesight, with the exception of use of Izanagi, but it also gives the person greater power. The eternal Mangekyō Sharingan also seems to change form from the original, with what appears to be a fusion of the current owners Mangekyō with the previous owners.