Thai Transliteration

Thai spelling doesn't tell you how a word sounds. Tone and vowel length have to be worked out from the consonant class, the syllable shape, and any tone marks. The six schemes below are different ways of writing down that answer.

Paiboon+

The romanization from Paiboon Publishing's learner books and the Three-Way Thai-English-Thai dictionary. English-reader conventions: aspirated stops stay bare (p, t, k), unaspirated ones use digraphs (bp, dt, g). Long vowels double, tones sit as diacritics on the first vowel, mid is unmarked. If you learned Thai from a Paiboon book, you already read this.

RTL — Rak Thai Language school

From Rak Thai Language School's course materials. Latin plus four IPA vowels (ʉ ɛ ɔ ə), aspirated stops as digraphs (kh, th, ph), tones as diacritics on the first vowel. Mid tone always carries a macron, which is the main thing distinguishing it from Paiboon+.

IPA — International Phonetic Alphabet

Broad phonemic IPA, in the format Wiktionary uses. Syllables separated by dots, wrapped in slashes, tones written with Chao tone letters (˧ mid, ˨˩ low, ˥˩ falling, ˦˥ high, ˩˩˦ rising). The most precise of the five, and the one we benchmark against.

RTGS — Royal Thai General System

What you see on road signs, passports, and most Wikipedia place names. Plain Latin letters, no tones, no vowel length. Fine for spelling names. Useless for learning: with only RTGS you can't tell how a word is actually pronounced.

TLC — thai-language.com

The Enhanced Phonemic notation from thai-language.com. ASCII Latin letters plus a tone tag at the end of each syllable: {M} mid, {L} low, {H} high, {F} falling, {R} rising. Useful for plain-text contexts where Unicode diacritics would get mangled.

Whatever you pick is remembered by your browser. Once the dictionary and lesson pages are wired to the engine, they'll show Thai in the same scheme everywhere.

What is Thai transliteration?

Writing Thai pronunciation in Latin or Cyrillic letters so you can read it without knowing the Thai alphabet. There isn't one standard. Paiboon+ and RTL target English-speaking learners, RTGS is the official Thai government system, IPA is for linguists, and TLC is the notation on thai-language.com.

How is Thai romanized?

Each syllable gets broken into onset, vowel, and coda, then mapped to Latin or Cyrillic letters. Tone is encoded separately: IPA Chao letters, bracketed tags like {H}, or diacritic marks on the vowel. There's no official system for everyday use, which is why half a dozen competing schemes coexist.

Why are there multiple Thai transliteration systems?

Different audiences, different goals. Paiboon+ fits English reading habits. RTL comes from one school's teaching method. IPA was built for cross-language precision. RTGS is the government standard but drops tones, so it's useless for learners. TLC is thai-language.com's in-house notation. No one scheme covers all of that.

Does this tool support Paiboon+, RTGS, and RTL?

Yes. Paiboon+, RTL, IPA, RTGS, and TLC are all available. Russian-speaking users also get Morev and Lipilina Cyrillic. Pick a scheme from the dropdown; your choice is remembered by the browser.

Can this tool transliterate full Thai sentences?

No, one word at a time. Thai has no spaces between words, and this tool doesn't do the word-segmentation step a sentence would need. If you paste a sentence, syllable boundaries and tones come out wrong. Feed it word by word.

Is this Thai transliteration tool free?

Yes, no account required. It runs on thaiphon, an open-source engine (see Source code below). Use it for flashcards, subtitles, lesson prep, whatever you need.