Based on available documentation and examples: Vapi.ai does not explicitly list Swiss German (gsw) among supported languages. That said, unsupported or obscurer dialects may still function if integrated via the platform’s transcription and TTS providers, but likely without dialect-specific accuracy or native-sounding voices. For best results, you'd use a Standard German voice (e.g., de-CH locale code) or a multilingual voice fallback, with a system prompt guiding responses to “Swiss German” users. The platform lacks built-in dialect-specific support in its public documentation.

Hello, Thank you for sharing this feedback with us, we really appreciate it. Could you clarify whether your use case requires precise Swiss German transcription and natural-sounding voices, or if using Standard German with a customized system prompt would be sufficient for your needs? You may also check Universal-Streaming in AssemblyAI’s speech-to-text model built for voice agents. It provides stable transcripts in around 300ms, with intelligent endpointing and strong accuracy. This helps prevent issues such as misheard account numbers, long pauses, or early cutoffs, making conversations smoother and more natural.

Natural sounding voices for swiss

We may not have native support for Swiss German specifically in terms of voice options, but we do support custom voice integrations. Here are some suggestions for Swiss German voices: Narakeet — offers two Swiss German voices (male + female) with natural, realistic tone. You can use their online tool or programmatically via API. Wikipedia+14Narakeet+14Murf AI+14 Maestra AI — supports Swiss German TTS with authentic voices, suitable for content such as audiobooks, ads, and videos. Narakeet+4Maestra AI+4Fineshare+4 FineVoice by Fineshare — includes Swiss German male and female voices, customizable and available via their online TTS platform. TTSFree+10Fineshare+10Murf AI+10 Verbatik — provides 3+ professional Swiss German voices with adjustable speech parameters and narrator-style presentation. verbatik.com+2verbatik.com+2 SlowSoft — a Swiss company offering speech synthesis in Swiss German (Zurich and Grisons dialects), plus Rhaeto‑Romanic and Swiss Standard German. Maestra AI+12slowsoft.ch+12stt4sg.fhnw.ch+12 VoBox — creates lifelike Swiss German voiceovers in MP3/WAV format with male and female options. To integrate these voices, check the documentation page to view instructions on how to do so: https://docs.vapi.ai/customization/custom-voices/custom-tts