Khecarī Mudrā (Sanskrit, खेचरी मुद्रा) is a yoga practice which is carried out by placing the tongue above the soft palate and into the nasal cavity. In the beginning stages and applicable for most practitioners, the tip of the tongue touches the soft palate as far back as possible without straining or placed in contact with the uvula at the back of the mouth. Variant spellings include Khechari Mudra, Kecharimudra, and Kechari Mudra. Mudrā (Sanskrit, मुद्रा, literally "seal"), when used in yoga, is a position that is designed to awaken spiritual energies in the body.
The buddhist Pali canon contains three passages in which the Buddha describes pressing the tongue against the palate for the purposes of controlling hunger or the mind (example), depending on the passage. However, there is no mention of the tongue being inserted into the nasopharynx as in true kechari mudra.
A hathayoga text, the Khecarīvidyā, states that kechari mudra enables one to raise Kundalini and access various stores of amrita in the head, which subsequently flood the body. Siva, in the same text, gives instructions on how to cut the lingual frenulum as a necessary prerequisite for the kechari mudra practice.
A tantric Saiva text, the Mālinīvijayottaratantra, warns:
[If] his mouth fills with a slightly salty liquid that smells of iron then he should not drink it but spit it out. He should practice thus until [the liquid] becomes sweet-tasting.
Bhattacharyya defines Khecarī Mudrā as "name of Yogic posture which bestows spiritual attainment and enables one to overcome disease and death." He explains that "Kha denotes brahman, and that power which moves (cara) as the kinetic energy of brahman is known (as) Khecarī." Singh defines Khecarī Mudrā as "the bliss of the vast expanse of spiritual consciousness, also known as divya mudrā or Śivāvasthā (the state of Śivā)." He further identifies it in a higher sense—with the end state of consciousness, and not just the physical posture used to achieve that end: "So Khecarī Mudrā in Śaiva āgama means a state of universal consciousness which is the state of Śiva." Abhinavagupta, in his Tantraloka, states that all other mudras derive from Khecarī mudrā, which he describes as "the stance of moving or flying through the void of the supreme consciousness." The practice is also mentioned in the Hatha Yoga Pradipika (III. 6-7).
Through the performance of Kechari Mudra, touching the tip of the tongue to the uvula, or "little tongue," (or placing it in the nasal cavity behind the uvula), that divine life-current draws the prana from the senses into the spine and draws it up through the chakras to Vaishvanara (Universal Spirit), uniting the consciousness with spirit.— 
According to Swami Kriyananda, "The assumption of this mudra helps to hasten the advent of deep spiritual states of consciousness." Swami Sivananda described Khecarī Mudrā as "the best of all Mudras."
In Kriya Yoga, the benefits of Khecarī Mudrā are achieved by pronouncing certain vowel while breathing in and breathing out.
- For romanization of the Sanskrit term as khecarī mudrā, see: White 1996, p. 135
- Flood, p. 100
- Janakananda, p. 114
- Kriyananda, p. 450-451
- Venkataratam, p. 4
- Yogananda, p. 173
- Kriyananda, p. 450
- Mallinson, James. 2007. The Khecarīvidyā of Adinathā. London: Routledge. pg.17-19.
- Mallinson, James. 2007. The Khecarīvidyā of Adinathā. London: Routledge. pg.29.
- Mallinson, James. 2007. The Khecarīvidyā of Adinathā. London: Routledge. pg.119.
- Mallinson, James. 2007. The Khecarīvidyā of Adinathā. London: Routledge. pg.22.
- Bhattacharyya, p. 407
- Singh, p. 242
- "Khecarī Mudrā is of various sorts. Śaiva āgama does not set any store by mudrā in the sense of disposition of certain parts of the physical body. It interprets mudrā in a higher sense in three ways, viz. (1) mudam (harṣam) rati (dadāti) — that which give muda or joy, (2) muṃ drāvayati — that which dissolves mu or bondage (3) mudrayati iti — that which seals up (the universe into turīya).... That which enables living beings to acquire Self-realization in all the states of the embodied ones is Mudrā.... So Khecarī Mudrā in Śaiva āgama means a state of universal consciousness which is the state of Śiva". Singh, pp. 101-102
- Muller-Ortega, p. 350.
- "While practicing Kriya, when the mind becomes enchanted in listening to nada, the sound of Aum, a divine nectar-like current flows from the sahasrara. Through the performance of Kechari Mudra,...that divine life-current..." Lal Ghosh, p. 279
- "This union can be achieved physically also, by what is known in yoga as kechari mudra — touching the tip of the tongue to nerves in the nasal passage, or to the uvula at the back of the mouth." Yogananda, p. 173
- Discourses of Paramahansa Yogananda. Lal Ghosh, p.279
- Kriyananda, p. 451
- Sivananda, p. 59
- Bhattacharyya, N. N. (1999), History of the Tantric Religion (Second Revised ed.), New Delhi: Manohar, ISBN 81-7304-025-7
- Flood, Gavin (1996), An Introduction to Hinduism, Cambridge University Press, ISBN 0-521-43878-0
- Janakananda, Swami (1992), Yoga, Tantra and Meditation in Daily Life, Weiser, ISBN 978-0-87728-768-1
- Kriyananda, Swami (2002), The Art and Science of Raja Yoga, Crystal Clarity Publishers, ISBN 978-1-56589-166-1
- Lal Ghosh, Sananda (1980), Mejda: The Family and the Early Life of Paramahansa Yogananda, Self-Realization Fellowship Publishers, ISBN 978-0-87612-265-5
- Mallinson, James (2007), The Khecarīvidyā of Adinathā, Routledge, ISBN 978-0-415-39115-3
- Muller-Ortega, Paul E. (2001), "A Poem by Abhinava Gupta", in White, David Gordon, Tantra in Practice, Motilal Banarsidass, p. 580, ISBN 978-81-208-1778-4
- Singh, Jaideva (1979), Śiva Sūtras, Delhi: Motilal Banarsidass, ISBN 81-208-0407-4
- Sivananda, Swami (2005), Kundalini Yoga, Divine Life Society, ISBN 978-81-7052-052-8
- K. R. Venkataraman; M. K. Venkatarama Iyer; K. R. Srinivasa Iyengar (1976), The Age of Vidyaranya, Kalpa Printers and Publishers
- White, David Gordon (1996), The Alchemical Body: Siddha Traditions in Medieval India, Chicago: The University of Chicago Press, ISBN 0-226-89499-1
- Yogananda, Paramhansa (2003), The Essence of Self-Realization, Crystal Clarity Publishers, ISBN 0-916124-29-0