Hand Seal

are used to perform many ninjutsu, genjutsu, and other secret arts other than taijutsu. The exact amount of chakra necessary to perform a jutsu is manipulated through hand seals. There are different sequences of hand seals for every technique, requiring memorization.

While techniques may require a number of hand seals to work, a skilled ninja can use less or even one to perform the same technique. An example of this is the Water Release: Water Dragon Bullet Technique, which requires a total of 44 hand seals to activate. Tobirama Senju, the Second Hokage, only needed to use one hand seal to complete the technique, a testament to his skill. In fact, by Part II, Sasuke Uchiha has managed to master the Chidori to the point of not needing a single hand seal to invoke it.

Although rare, it is possible for a shinobi to be able to do hand seals with just one hand. The only shinobi seen so far capable of this are Haku and Guren.

Basic Seals
There are twelve basic seals, each one named after an animal of the Chinese zodiac.
 * This hand seal is commonly affiliated with the movie only Ice Release and with Danzō's Wind Release.
 * This hand seal is commonly affiliated with Fire Release.
 * This hand seal is commonly affiliated with Earth Release and with Wood Release.
 * This hand seal is commonly affiliated with the special Shadow Techniques of the Nara clan.
 * This hand seal is commonly affiliated with Fire Release.
 * This hand seal is commonly affiliated with Earth Release and with Wood Release.
 * This hand seal is commonly affiliated with the special Shadow Techniques of the Nara clan.
 * This hand seal is commonly affiliated with the special Shadow Techniques of the Nara clan.

Other Hand seals
Besides the twelve basic hand seals, there are unique hand seals used for certain techniques. These hand seals are rarely seen, and can be considered unique to specific jutsu.

Tiger/Ram with one hand
Although it's unknown if this is a seal, this motion is often used to concentrate chakra, and many shinobi are seen initiating simple, basic jutsu after making this seal. Deidara also often used this when he detonated his Exploding Clay and Sai used it for his Super Beasts Imitation Picture.

Shadow Clone Seal
The Shadow Clone Technique seal is different from the basic twelve seals. Index and middle fingers from both hands are crossed.

Clap hands
This is more of an initiation of a jutsu rather than a hand seal where the user simply claps their hands together. The hand seal sequence for powerful summoning Kinjutsu like the Summoning: Impure World Resurrection and the Dead Demon Consuming Seal end with this motion; similarly, Jiraiya prepares to enter Sage Mode (summoning Shima and Fukasaku) by performing this motion and sustaining it. Its also used by Naruto Uzumaki when he's summoning chakra or breaking genjutsu. Once the seal sequence completed, the user's hands are held in this position until the desired effect is achieved.

Slam ground
Used in techniques such as the Summoning Technique, this is also more of an initiation of a jutsu than a seal. The user presses their hand to the surface that is affected.

Haku's Seals
The seals used for Haku's Thousand Flying Water Needles of Death, are quite different than the basic twelve seals, and are also performed with one hand.

Crossed Tiger
Haku's Demonic Ice Crystal Mirrors jutsu can be done with a special seal, which resembles Tiger with middle fingers crossed over the index fingers. Interestingly, Orochimaru also uses this seal when giving the Cursed Seal of Heaven to an individual.

Jin Seal
This is another one of the seals that are used in normal techniques, yet isn't one of the basic twelve seals. The seal is used in techniques such as the Water Release: Water Dragon Bullet Technique and the Shrine Seal. In the anime, this seal is formed similar to the Dog seal, but the left hand is under the right, and the left's palm is facing up.

Akimichi Seal
The Akimichi clan use a certain seal in their Multi-Size Technique, which also resembles the Bird seal from frontal view. (However, it is confirmed that this is a different seal, as the Bird seal has been seen in a side view in techniques such as Water Release: Water Dragon Bullet Technique and the Shadow Sewing Technique.) The index and little fingers are raised up, the middle and ring fingers are each folded on top of the hand opposite itself and interlocked with each another, and the thumbs are pressed together at their end segments.

In the anime, there are several "variations" to this seal, likely mistakes. Sometimes, it is formed like the Half Tiger, with the little fingers also raised. Other times, it is formed more similarly in fashion to the Bird seal instead, with index and little fingers raised, and with the thumb and middle and ring fingers are folded in and pressed against each other.
 * This seal is therefore very controversial, as this seal was used instead of the Bird seal multiple times in the anime or in movies, likely a mistake.

Mind Technique Seals
The Yamanaka clan uses different seals to activate their techniques, such as the Mind Body Switch Technique and the Mind Body Disturbance Technique. Another seal was used to release the Mind Body Switch Technique and return to the original body. This seal resembled both hands' fingers straightened and crossed into an "X", similar to the Ox seal (however not a "+"), but without the left middle and ring fingers down.

Half Tiger
The half tiger is the symbol of combat and is a universal sign of engagement between shinobi. It represent half of a seal that might be used to activate a ninjutsu.

Twin Snakes Mutual Death Seal
A hand seal involving both the user and the enemy is used in the kinjutsu Twin Snakes Mutual Death.

Mangekyō Sharingan Activation Seal
Probably another seal used to gather and focus chakra, it was used by Kakashi in his first battle with Deidara, when he activated his Mangekyō Sharingan to use Kamui for the first time seen in the series. It is formed like the Tiger seal, except with the index fingers' end segments pushed down against each other, forming a house-like shape in the user's point of view. When Kakashi used it, he positioned it in front of his left eye.

Sasuke's Snake Seal
Sasuke used a seal, similar to the Akimichi seal, in his battle with Deidara, when he used either Hidden Shadow Snake Hands or Snake Authority Spell.
 * As with the Akimichi seal, this technique also draws controversy with the Bird seal, as it seems similar from a frontal view. However, side view comparisons of this seal and the Bird seal in Water Release: Water Dragon Bullet Technique and/or Shadow Sewing Technique show that this is a different seal.

Daytime Tiger Seal
This seal is used in Daytime Tiger. It does not release chakra, but rather keeps it inside the body to use as energy and strength. This creates a missile type of jutsu which is not a body of chakra. This seal is actually based off one of the original Kuji-jin seals, the seal of the Outer Lion. In this case, the hands are meant to resemble a tiger. The index fingers (the "eyes" of the Tiger) glow green with the evaporating green sweat of the user (result of releasing the Gate of Wonder).

Great Shark Bullet Seal
Kisame's Water Release: Great Shark Bullet Technique requires this seal. Possibly a comparison to Guy's Daytime Tiger seal, which resembles a tiger, this hand seal is a thrust, but with both hands touching at the wrist and right hand above the left. The fingers are also folded in a way that vaguely resembles shark's teeth. This overall placement of the hands resembles a shark with an open jaw.

Anime Byakugan seals
In the anime, certain variant seals to aid in the activation of the Byakugan are seen. Most are some of the basic twelve seals, but several are different. In the manga, seals are indeed used several times, but of course, they cannot be seen with detail.

Anime Water Encampment Wall
In the anime, a special seal is used instead of what is seen in the manga for the Water Release: Water Encampment Wall Technique.

Fūma Curse Mandala Seals
In the anime, the Fūma clan used various unknown hand seals for their Hiden jutsu, the Curse Mandala.

Guren's Unknown Crystal Seals
Several "unknown" seals are used in Crystal Release: Crystal Encampment Wall.

Tornado Lightning Seal
In Naruto the Movie 2: Legend of the Stone of Gelel, Ranke uses an unknown hand seal to activate her Tornado Lightning. However, considering that neither she nor her comrades knew what ckakra is, her technique is unlikely to be ninjutsu, and her "hand seal" is likely merely an attack gesture.

Land of Demons' Seals
In Naruto: Shippūden the Movie, the shinobi affiliated with the Land of Demons use unique seals unused by the usual shinobi seen throughout the series.

Shadow Mirror Change Seals
Taruho used the Shadow Mirror Body Changing Method, which used hand seals like:
 * Tiger, but with little fingers pressed inwards instead
 * Tiger/Ram with left hand, and right hand with thumb up "punching" the left
 * Boar, but with left hand pointed upwards instead
 * Right hand facing down above left, left hand facing up below right; Each hand's index and middle fingers folded, and ring and little fingers straight

Shrine Seal Seals
Also, the Shrine Seal used by Shion (Yomi also used a technique by repeating the same seal names, although he only held his palm forward the whole time) uses a numerous amount of different seals with different names as followed: After completing the first three seals, Shion begins to levitate, the seal lights up, a barrier is formed around the seal, and the spheres inside the seal move around the circle. (Yomi did not have to do this.) After completing these 9 seals, the stone tablets in the shrine will arise in front of Shion. The first 4 of these are unseen and it may be that she only shouts these words while holding Shō. Yomi did not use these last 6 seals.
 * Hatsu: Right palm facing forward, fingertips directing to the right
 * Jin: Right hand Tiger/Ram facing down, placed under the eyes pointing towards the left
 * Kai: Right hand Tiger/Ram, pointing up with arm straight, facing forward
 * Min: Both palms pushed forward, fingertips pointing about 45 degrees up/forward
 * Shin: Both palms pressed together (like a clap)
 * Gan: Left fist "punching" right palm
 * Reppyō: "Rep" seems identical to the Snake/Earth seal. "Pyō" Each hand in half Tiger/Ram, arms stretched with fingertips pointing forward
 * Shōzen: Both hands in fists, left left above right; looks similar to the Rat seal
 * Mika: Seems identical to Min
 * Dan: Each hands revolves around one another into Tiger/Ram, right hand behind left
 * Raku: Left hand raised up facing down with middle and ring fingers folded and index and little fingers straight pointing towards the left, right palm pushed down facing down pointing forward
 * Shō: Left palm facing down in front with fingertips pointing right, right fist punching left palm from below
 * Fu: Hold Shō
 * Sai: Hold Shō
 * Dan: Hold Shō
 * Gika: Hold Shō
 * Ragu: Left hand pointing diagonally up/right 45 degrees, right hand middle and ring fingers folded index and little fingers straight pointing diagonally up/left placed in front of left forearm
 * Bagi: Right palm facing left with fingertips pointing up in front of user, left forearm behind right seal and left fist placed above right elbow

Hiruko's Storm Release Seal
In Naruto Shippūden 3: Inheritors of the Will of Fire, Hiruko uses a special seal for the Storm Release: Thunder Cloud Inner Wave, which resembles Tiger, but only with the middle fingers raised.

Trivia

 * In the anime, a kunoichi known as Hanare could use a mind reading technique that required the use of her eye by "weaving seals" with her right eye. How she does this exactly is unknown. This was not a dōjutsu kekkei genkai as it could be copied with the Sharingan.