The dashboard’s language picker is the live source of truth — it greys out combinations that aren’t supported and updates as providers add coverage. Use these tables for planning; confirm the exact combination in the dashboard. See Set language for your agent and Configure a multilingual agent for how selection works.
language field. Where a language has multiple locale variants (for example, US vs. British English), they share the same provider support.
Text-to-speech (voice) support
A ✓ means the language is supported by at least one of that provider’s voice models. Some providers gate certain languages to specific models — see Model-level restrictions below.Model-level restrictions
Most providers support the same languages across all of their models. The exceptions: ElevenLabs
Fish Audio
OpenAI (
tts-1, gpt-4o-mini-tts), Cartesia (sonic-3, sonic-3-latest, sonic-3.5), and MiniMax (speech-02-turbo, speech-2.8-turbo) support their full language set on every model.
Speech recognition (ASR) support
A ✓ means the provider can transcribe that language. By default Retell auto-routes across providers based on your agent’s languages and whether it’s optimized for latency or accuracy. You can also pin a specific provider manually with a custom speech-to-text config, as long as it supports every language your agent uses. See Speech recognition providers.- Azure covers every supported language and acts as the broad-coverage fallback.
- AssemblyAI supports code-switching across its listed languages.
- Deepgram and Soniox support any-to-any code-switching for multilingual agents across their supported languages; Azure is single-language only.