Assistant CoreAssistant Core
Voice

Standard vs Realtime Voice

Compare Standard Mode (VAD → STT → LLM → TTS) and Realtime Mode (Gemini Live, xAI Grok) — choose the right voice mode.

Standard Mode

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Realtime Mode

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Comparison

FeatureStandard ModeRealtime Mode
ArchitectureChained speech-to-text → AI → text-to-speechDirect speech-to-speech
LatencyModerate (processes in stages)Low (instant speech-to-speech)
Processing modelStandard pipeline: ASR + LLM + TTSSeparate realtime voice model
Voice QualityVery good (dedicated TTS)Excellent (native audio)
Tool SupportFull (web search, KB, etc.)Limited (provider-specific)
Text InputLLM → TTS pipelineSent directly to realtime session
Plan RequiredAny plan with voicePlan with Realtime models

When to Use Standard

  • Customer support — Structured Q&A with knowledge base
  • Flexible LLM choice — Standard uses a separate LLM for voice turns and a separate TTS model for spoken output
  • Tool usage — Needs web search, image generation, etc.
  • Cost control — Usually cheaper than Realtime for the same task

When to Use Realtime

  • Natural conversations — Back-and-forth dialogue
  • Low latency — Instant responses feel more natural
  • Simple queries — Don't need complex tool integrations
  • Voice-first experience — Prioritizes live conversation feel over long-form answers

Voice usage consumes credits based on the model and usage. See Credits & Usage for calculation details, and Plans & Pricing for Realtime availability.

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