International Alphabet of Sanskrit Transliteration

The International Alphabet of Sanskrit Transliteration (I.A.S.T.) is a transliteration scheme that allows a lossless romanization of Indic scripts as employed by the Sanskrit language. It is also used to romanize Pāḷi, Prākṛta and Apabhraṁśa.


IAST is especially used for books dealing with ancient Sanskrit and Pāḷi topics related to Indian religions. The script is, however, insufficient to represent both Sanskrit and Pāḷi on the same page properly because the (l with underdot), a vowel in Sanskrit (vocalic /l/), is the retroflex consonant in Pāḷi ([ɭ]). Here it is better to follow Unicode and ISO 15919, which is in any case a more comprehensive scheme.

IAST is based on a standard established by the International Congress of Orientalists at Geneva in 1894.[1][2] It allows a lossless transliteration of Devanāgarī (and other Indic scripts, such as Śāradā script); and, as such, it represents not only the phonemes of Sanskrit, but allows essentially phonetic transcription, e.g., visarga is an allophone of word-final r and s.

The National Library at Kolkata romanization, intended for the romanization of all Indic scripts, is an extension of IAST.

Inventory and conventions

The IAST letters are listed with their Devanāgarī equivalents and phonetic values in IPA, valid for Sanskrit, Hindi and other modern languages that use Devanagari script. Some phonological changes have occurred.

Vowels and codas
Devanāgarī Transcription Category
a A monophthongs
& syllabic liquids
ā Ā
i I
ī Ī
u U
ū Ū
e E diphthongs
ai Ai
o O
au Au
अं anusvara
अः visarga
अऽ ' avagraha
velars palatals retroflexes dentals labials

k  K

c  C

ṭ  Ṭ

t  T

p  P
tenuis stops

kh  Kh

ch  Ch

ṭh  Ṭh

th  Th

ph  Ph
aspirated stops

g  G

j  J

ḍ  Ḍ

d  D

b  B
voiced stops

gh  Gh

jh  Jh

ḍh  Ḍh

dh  Dh

bh  Bh
breathy-voiced stops

ṅ  Ṅ

ñ  Ñ

ṇ  Ṇ

n  N

m  M
nasal stops

h  H

y  Y

r  R

l  L

v  V
ś  Ś

ṣ  Ṣ

s  S

The highlighted letters are those modified with diacritics, e.g., long vowels are marked with an over-line, vocalic (syallabic) consonants and retroflexes have an under-dot.

Unlike ASCII-only romanizations such as ITRANS or Harvard-Kyoto, the diacritics used for IAST allow capitalization of proper names. The capital variants of letters which never occur word-initially (Ṇ Ṅ Ñ Ṝ) are useful only in Pāṇini contexts, where the convention is to typeset the IT sounds as capital letters.

Comparison with ISO 15919

For the most part, IAST is a subset of ISO 15919. The following five exceptions are due to the ISO standard accommodating an extended repertoire of symbols to allow transliteration of Devanāgarī and other Indic scripts as used for languages other than Sanskrit.

Devanāgarī IAST ISO 15919 Comment
ए/ े e ē ISO e represents ऎ/ ॆ.
ओ/ो o ō ISO o represents ऒ/ॊ.
 ं ISO represents Gurmukhi tippi  ੰ.
ऋ/ ृ ISO represents ड़ /ɽ/.
ॠ/ ॄ r̥̄ for consistency with .

See also


  1. ^ History of Skt. transcription and 1894, Rapport de la Trans.
  2. ^ Xme Congrès International des Orientalistes, Session de Genève. 1894. Rapport de la Commission de Transcription.

External links