Alternatives

OpenAI Realtime API alternatives in 2026 (Gemini Live, Cartesia, ElevenLabs Conversational, Vapi, LiveKit Agents)

Top OpenAI Realtime API alternatives in 2026: Gemini Live (multimodal video), Cartesia Sonic (lowest-latency TTS-led), ElevenLabs Conversational (quality-first), Vapi (multi-model voice platform), LiveKit Agents (WebRTC infrastructure).

Why people search this

People look for OpenAI Realtime alternatives because they want multimodal video / screen (Gemini Live), lower latency (Cartesia), best voice quality (ElevenLabs), multi-model voice platform (Vapi), or open-source WebRTC infra (LiveKit).

The ranking

#1

Gemini Live

Best for: Multimodal video / screen, vision-heavy real-time apps  ·  Price: Per-second + token (cheaper than OpenAI)

Google's realtime API with live video + screen + image input + audio — multimodal-first realtime conversation.

Read our deep dive →

#2

Cartesia Sonic

Best for: Lowest-latency voice agents, DIY pipeline  ·  Price: Per-character + paid tiers

Lowest-latency streaming TTS purpose-built for voice agents — pair with any STT + LLM for full pipeline.

#3

ElevenLabs Conversational

Best for: Voice quality, voice cloning, branded agents  ·  Price: Credits-based tiers

Highest-quality voice + Conversational AI with best-in-class voice cloning and emotion.

#4

Vapi

Best for: Multi-vendor voice agents, flexibility  ·  Price: Per-minute + per-token

Voice agent platform with model + TTS + STT flexibility (Claude, GPT, Gemini, ElevenLabs, Cartesia, Deepgram).

#5

LiveKit Agents

Best for: Open-source, self-host, custom WebRTC pipelines  ·  Price: Free OSS + LiveKit Cloud

Open-source WebRTC infrastructure for voice + video AI agents — self-hostable, used by ChatGPT Voice itself.

FAQ

Multimodal video?

Gemini Live — live video + screen + image input first-class.

Lowest latency?

Cartesia Sonic — sub-100ms streaming TTS for the TTS step.

Open-source?

LiveKit Agents — self-host WebRTC infra used by ChatGPT Voice itself.

Related

Last updated: 2026-06-01.