Voice AI - Supported Languages & Recommended Stacks
Availability tiers evolve as new languages are validated — check with your Exotel representative for the latest information.
How a voice agent is assembled
Every Exotel voice bot is built from three interchangeable pieces. When you set up a language in the console, you're choosing (or accepting the recommended default for) each one:
- Speech-to-Text (STT / ASR) — transcribes what the caller says.
- LLM — understands the caller and decides what to say back.
- Text-to-Speech (TTS) + Voice — speaks the reply in a natural voice.
Noise suppression and turn detection are applied by default on every stack, so you don't need to configure them.
Choosing your stack when you add a language
When you select a new language in the console, use this three-step guide:
- Find your primary language in the tables below — this is the language the bot mainly listens in and speaks.
- Pick one option from each column (STT, LLM, TTS/Voice). Where two providers are listed, either works; pick one and keep it consistent across STT and TTS, because some secondary-language and code-switching behaviour only works when STT and TTS come from the same provider (noted per row).
Availability
- Certified (Generally Available) — Fully validated across multiple datasets and evaluations.
- Beta — Live in production with real customer deployments and improving continuously.
- Alpha (Early Access) — Available for experimentation and to take to Beta.
Certified languages
Language | STT (pick one) | LLM | TTS / Voice | Secondary language in same call | Proven use cases |
|---|---|---|---|---|---|
English (en) | Deepgram or ElevenLabs | Gemma | Smallest AI or ElevenLabs — voice Avni (default) | Hindi | Customer Care, Collections, Hospital Appointments |
Hindi (hi) | Deepgram or ElevenLabs | Gemma | Smallest AI or ElevenLabs — voice Avni (default) | English | Customer Care, Collections, Hospital Appointments |
Beta languages
Language | STT (pick one) | LLM | TTS / Voice | Secondary language in same call | Proven use cases |
|---|---|---|---|---|---|
Arabic (ar) | ElevenLabs or Speechmatics | Gemini | ElevenLabs or Amazon Polly | English — only when both STT and TTS are ElevenLabs | Order Status |
Alpha / Early Access — Indian languages
Language | STT (pick one) | LLM | TTS (pick one) | Secondary languages in same call | Proven use cases |
|---|---|---|---|---|---|
Tamil (ta) | ElevenLabs or Gemini | Gemma or Gemini (no-thinking) | ElevenLabs or Gemini | English & Hindi (ElevenLabs); Hindi, English & Indic (Gemini) | Collections |
Telugu (te) | Gemini or Sarvam | Gemini | Gemini or Sarvam | Hindi, English & Indic (Sarvam or Gemini) | Collections |
Marathi (mr) | ElevenLabs or Gemini | Gemini | ElevenLabs or Gemini | English & Hindi (ElevenLabs); Hindi, English & Indic (Gemini) | Collections, KYC |
Kannada (kn) | Azure or Sarvam | Gemini 2.5 Flash or Gemma 3 (26B) | Google or Sarvam | English, Hindi, Tamil, Telugu, Malayalam (Gemini or Sarvam) | Customer Care, Collections |
Malayalam (ml) | Azure or Sarvam | Gemini 2.5 Flash or Gemma 3 (26B) | Google or Sarvam | English, Hindi, Tamil, Kannada, Telugu (Gemini or Sarvam) | Customer Care, Collections, KYC |
Gujarati (gu) | Azure or Sarvam | Gemini 2.5 Flash or Gemma 3 (26B) | Google, Sarvam or ElevenLabs | English, Hindi, Marathi (Gemini or Sarvam) | Collections, Lead Qualification |
Bengali (bn) | Azure or Sarvam | Gemini 2.5 Flash | Google or Sarvam | English, Hindi (Gemini or Sarvam) | Customer Care, Collections |
Punjabi (pa) | Azure or Sarvam | Gemini 2.5 Flash or Gemma 3 (26B) | Sarvam | English, Hindi (Sarvam) | Collections |
Odia (or) | Azure or Sarvam | Gemini 2.5 Flash | Sarvam | English, Hindi (Sarvam) | Customer Care |
Alpha / Early Access — International languages
Language | STT (pick one) | LLM | TTS (pick one) | Secondary language in same call | Proven use cases |
|---|---|---|---|---|---|
Indonesian / Bahasa (id) | Speechmatics or Azure | Gemini 2.5 Flash or Gemma 3 (26B) | ElevenLabs or Google | English (ElevenLabs or Speechmatics) | Rider Onboarding, Customer Care |
Filipino / Tagalog (fil / tl) | Speechmatics or Azure | Gemma 3 (26B), Gemini 2.5 Flash or Gemini 2.5 Flash (Fast) | ElevenLabs or Cartesia | English (ElevenLabs, Speechmatics or Cartesia) | Customer Care, Collections |
Malay / Bahasa (ms) | Azure or Speechmatics | Gemini 2.5 Flash | ElevenLabs | English (ElevenLabs) | Customer Care |
Vietnamese (vi) | Azure | Gemini 2.5 Flash | English (Google) | Customer Care | |
Thai (th) | Azure | Gemini 2.5 Flash | English (Google) | Customer Care | |
Swahili (sw) | Azure or Speechmatics | Gemini 2.5 Flash or Gemma 3 (26B) | Google or ElevenLabs | English (Google or ElevenLabs) | Customer Care, Rider Onboarding |
Japanese (ja) | Azure | Gemini 2.5 Flash or GPT-4.1 Mini | Google or Cartesia | English (Google or Cartesia) | Customer Care |
Mandarin Chinese (cmn) | Azure | Gemini 2.5 Flash | English (Google) | Customer Care | |
French (fr) | Azure | Gemini 2.5 Flash | Google or ElevenLabs | English (Google or ElevenLabs) | Customer Care |
Spanish (es) | Azure | Gemini 2.5 Flash | Google or ElevenLabs | English (Google or ElevenLabs) | Customer Care |
German (de) | Azure | Gemini 2.5 Flash | English (Google) | Customer Care |
Notes
- To use a secondary language in the same call (code-switching), keep STT and TTS on the provider named in that row — mixing providers may disable it.
- For the full voice catalogue per language, ask your Exotel contact for the voice library.