The International Alphabet of
(I.A.S.T.) is a
transliteration scheme that allows the lossless romanization of Indic
scripts as employed by
and related Indic languages. It is
based on a scheme that emerged during the nineteenth century from
suggestions by Charles Trevelyan, William Jones, Monier
Monier-Williams and other scholars, and formalised by the
Committee of the Geneva Oriental Congress, in
September 1894. IAST makes it possible for the reader to read the
Indic text unambiguously, exactly as if it were in the original Indic
script. It is this faithfulness to the original scripts that accounts
for its continuing popularity amongst scholars.
2 Inventory and conventions
3 Comparison with ISO 15919
4 Computer input by alternative keyboard layout
5 Computer input by selection from a screen
7 See also
9 External links
University scholars commonly use IAST in publications that cite
textual material in Sanskrit,
Pāḷi and other classical Indian
IAST is also used for major e-text repositories such as SARIT,
Muktabodha, GRETIL, and sanskritdocuments.org.
The IAST scheme represents more than a century of scholarly usage in
books and journals on classical Indian studies. By contrast, the ISO
15919 standard for transliterating Indic scripts emerged in 2001 from
the standards and library worlds; it includes solutions to problems
such as representing Old Indo-Aryan and New Indo-Aryan languages side
by side in library catalogues, etc. For the most part, ISO 15919
follows the IAST scheme, departing from it only in minor ways (e.g.,
ṃ/ṁ and ṛ/r̥)—see comparison below.
The Indian National Library at Kolkata romanization, intended for the
romanization of all Indic scripts, is an extension of IAST.
Inventory and conventions
Further information: Help:IPA/Sanskrit
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, but some phonological changes
Vowels and codas
and syllabic liquids
The highlighted letters are those modified with diacritics: long
vowels are marked with an overline, vocalic (syllabic) consonants and
retroflexes have an underdot.
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 never occurring word-initially (Ṇ Ṅ Ñ
Ṝ) are useful only when writing in all-caps and in Pāṇini
contexts for which the convention is to typeset the IT sounds as
Comparison with ISO 15919
For the most part, IAST is a subset of
ISO 15919 that merges: the
retroflex (underdotted) liquids with the vocalic ones (ringed below);
and the short close-mid vowels with the long ones. The following seven
exceptions are from the ISO standard accommodating an extended
repertoire of symbols to allow transliteration of
other Indic scripts, as used for languages other than Sanskrit.
ए / े
ISO e generally represents ऎ / ॆ, but optionally represents long
ए / े in Devanagari, Bengali, Gurmukhi, Gujarati, and Oriya
ओ / ो
ISO o generally represents ऒ / ॆ, but optionally represents long
ओ / ो in Devanagari, Bengali, Gurmukhi, Gujarati, and Oriya
अं / ं
ISO ṃ represents
Gurmukhi tippi ੰ.
ऋ / ृ
ISO ṛ represents ड़ /ɽ/.
ॠ / ॄ
for consistency with r̥.
ऌ / ॢ
ISO ḷ represents ळ /ɭ̆/.
ॡ / ॣ
for consistency with l̥.
Computer input by alternative keyboard layout
The most convenient method of inputting romanized
Sanskrit is by
setting up an alternative keyboard layout. This allows one to hold a
modifier key to type letters with diacritical marks. For example,
alt+a = ā. How this is set up varies by operating system.
Linux systems allow one to set up custom keyboard layouts
and switch them by clicking a flag icon in the menu bar.
macOS One can use the pre-installed US International keyboard, or
install Toshiya Unebe's Easy
Unicode keyboard layout. A revision of
this is Shreevatsa R's EasyIAST.
Microsoft Windows Windows also allows one to change keyboard layouts
and set up additional custom keyboard mappings for IAST.
Computer input by selection from a screen
Unicode input#Selection from a screen
Applet for character selection
Many systems provide a way to select
Unicode characters visually.
ISO/IEC 14755 refers to this as a screen-selection entry method.
Microsoft Windows has provided a
Unicode version of the Character Map
program (find it by hitting ⊞ Win+R then type charmap then hit ↵
Enter) since version NT 4.0 – appearing in the consumer edition
since XP. This is limited to characters in the Basic Multilingual
Plane (BMP). Characters are searchable by
Unicode character name, and
the table can be limited to a particular code block. More advanced
third-party tools of the same type are also available (a notable
freeware example is BabelMap).
macOS provides a "character palette" with much the same functionality,
along with searching by related characters, glyph tables in a font,
etc. It can be enabled in the input menu in the menu bar under System
Preferences → International → Input Menu (or System Preferences
→ Language and Text → Input Sources) or can be viewed under Edit
→ Emoji & Symbols in many programs.
Equivalent tools – such as gucharmap (GNOME) or kcharselect
(KDE) – exist on most
Linux desktop environments.
Users of SCIM on
Linux based platforms can also have the opportunity
to install and use the sa-itrans-iast input handler which provides
complete support for the
ISO 15919 standard for the romanization of
Indic languages as part of the m17n library.
This section needs expansion. You can help by adding to it. (September
Only certain fonts support all Latin
Unicode characters for the
transliteration of Indic scripts according to the
ISO 15919 standard.
For example, Tahoma supports almost all the characters needed. Arial
Times New Roman
Times New Roman font packages that come with Microsoft Office 2007
and later also support most
Latin Extended Additional characters like
ḑ, ḥ, ḷ, ḻ, ṁ, ṅ, ṇ, ṛ, ṣ and ṭ.
However, the growing trend amongst academics working
in the area of
Sanskrit studies is towards using
Gentium font which
has complete support for all the conjoined diacritics used in the IAST
National Library at Kolkata romanization
^ Monier-Williams, Monier (1899). A Sanskrit-English Dictionary (PDF).
Oxford: Clarendon Press. pp. xxx.
Shashir Reddy, "Shashir's Notes: Modern Transcription of Sanskrit."
Anthony Stone, "
Transliteration of Indic Scripts: How to use ISO
Dominik Wujastyk, "
Transliteration of Devanagari." 
Typing a macron - page from Penn State University about typing with
International Phonetic Alphabet
International Phonetic Alphabet chart with pronunciation guide
A visual chart which shows clearly 1. Which part of the mouth for each
sound 2. The 3 groups where the 12 diacritics appear. - from
Sanskrit Pronunciation Tips for beginners & Simple Charts to help
memorize where the diacritics fit in. - pages from Dina-Anukampana Das
A pronunciation guide with chart and pronunciation tips. - from
IAST <==> Devanagari online converter (
^ Reddy, Shashir. "Shashir's Notes: Modern Transcription of Sanskrit".
^ Stone, Anthony. "
Transliteration of Indic Scripts: How to use ISO
15919". Archived from the original on 14 April 2016. Retrieved 2
December 2016. CS1 maint: BOT: original-url status unknown (link)
^ Wujastyk, Dominik (1996). "
Transliteration of Devanagari". INDOLOGY.