ChindaMT Thai-English Translator

Translate Now​

Pick an example or paste your own text, choose the direction, and add rules in plain English if you want a particular tone or wording. With "compare" ticked, you also get the translation without your rules, side by side. Log in with your iApp account; each translation costs 1 IC per 400 characters, and a rejected request is not charged.

curl -X POST 'https://api.iapp.co.th/v3/store/text/mt/translate' \
  -H 'apikey: YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"text":"The meeting has been moved to Friday because the boss is busy.","source_lang":"en","target_lang":"th","rules":["Use a casual, friendly tone"]}'

One Sentence, Two Translations​

The same English sentence, translated by ChindaMT with and without one rule:

Source: "The meeting has been moved to Friday because the boss is busy."

How to Use​

1. Log in and pick an API key. The translator uses your iApp account; new accounts can create a key on the API Keys page.
2. Choose the direction. English to Thai or Thai to English. The swap button reverses it.
3. Paste your text. Up to 100,000 characters. Line breaks and indentation are kept, and each line is translated on its own.
4. Add rules if you need them. One per line, in plain English, for example Use a formal tone or Translate บาท as THB. Rules are free; only the text is charged.
5. Press Translate. A sentence comes back in about 0.4 seconds, five pages in under 2 seconds. Copy the result with one click.

Rules You Can Give​

Who It Is For​

Measured Quality​

In the accompanying research paper (AACL-IJCNLP 2026, Main Conference), a judge model preferred ChindaMT-4B's translation over Typhoon-Translate-1.5-4B in 68.4% of comparisons with rules, over TranslateGemma-4B in 87.2% and over MiLMMT-46-4B in 89.5%. In a blind test, three native Thai speakers preferred ChindaMT-4B in 69% of translations with rules. Without rules, quality does not drop: on FLORES-200 it scored the highest of the 4B to 9B models tested. Full numbers are in the API documentation.

Learn More​

Frequently Asked Questions​

Is it free? You need an iApp account with credits. Translation costs 1 IC per 400 characters of your text; rules are free. A short sentence costs 1 IC. Failed or rejected requests are not charged. New accounts receive a welcome bonus of free credits.

Which languages does it support? Thai and English, in both directions.

How long can the text be? Up to 100,000 characters per request, about 50 pages. Longer documents can be sent in several parts.

Are Thai vowels and tone marks counted? Yes. Each vowel and tone mark is one character, so ที่ counts as 3.

Is my text stored? No. Text is translated on iApp-operated servers in Thailand and is not sent to any third party. Logs record only the character count.

Can I run the model myself? Yes. ChindaMT-4B, 2B and 0.8B are open under Apache 2.0 on Hugging Face. For an on-premise setup with your own terminology, contact sale@iapp.co.th.