12 Best OpenAI Realtime API Alternatives (2026)
OpenAI Realtime API is openai's api for building voice agents that listen and talk back in real time over a website, app, or phone line, using one speech-to-speech model instead of separate transcription, reasoning, and voice pieces.. Teams that switch usually cite price at production volume, compliance requirements, deeper pipeline control, outbound campaign tooling, an out-of-the-box receptionist, ecommerce order handling. The alternatives below are ranked by published head-to-head verdicts, not sponsorship.
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Reviewed by vsref Editorialfacts verified Aug 20, 2026Methodology →
Where to switch, by reason
All 75 voice ai alternatives
How the top OpenAI Realtime API alternatives compare
The top 6 in depth: where each alternative ranks across the Voice AI field we track, which use cases it takes from OpenAI Realtime API, and what switching gives up.
1. Vapi
Among the 23 voice ai tools we track, Vapi has the 7th-cheapest per-minute rate - a fit for cost-sensitive, high-volume work.
Head-to-head, Vapi takes custom pipeline control, ecommerce support and orders, outbound sales campaigns and smb receptionist and booking from OpenAI Realtime API and matches it for healthcare compliance.
Before switching, weigh what stays behind - OpenAI Realtime API vs Vapi: no bring-your-own llm.
Its published rate is $0.05 per minute, verified July 2026.
Why teams switch: For engineering teams building custom pipelines, the ability to swap in your own LLM and TTS voice are deciding factors. Vapi supports both bring-your-own LLM and bring-your-own TTS voice, while the OpenAI Realtime API supports neither. Both tools are fully API-first, so that is a wash. Vapi also includes a simulation and testing suite, which the OpenAI Realtime API has no documented equivalent for. SIP trunking is available on both. Vapi's reported median latency is 600 ms, and the OpenAI Realtime API publishes no comparable figure. The flexibility advantages Vapi offers across the most important criteria are decisive.
Custom pipeline control verdict →
Overall verdict: Vapi wins four of five use cases, with only a tie in healthcare compliance. Its no-code agent builder, built-in knowledge base, native outbound campaigns, warm transfer, and number provisioning give it a complete telephony stack that the OpenAI Realtime API simply lacks. Vapi also supports bring-your-own LLM and bring-your-own TTS voice, while OpenAI Realtime API supports neither. Integrations with GHL, Twilio, Zapier, and Make accelerate ecommerce and SMB deployments. At a $0/mo platform fee with LLM and TTS costs passed through at cost, real production pricing runs $0.05 to $0.17 per minute, keeping costs transparent. Backed by a $50M Series B, Vapi is a credible production choice.
| Monthly volume | All-in monthly bill |
|---|---|
| 1K min/moSolo builder | $110 |
| 10K min/moAgency | $1,100 |
| 100K min/moCall center | $11,000 |
≈ $0.11 per minute all-in (est.), verified Jul 15, 2026. All-in monthly: platform fee + per-minute + telephony. Assumes GPT-4o class model, ElevenLabs voice. How we compute costs →
Full Vapi vs OpenAI Realtime API comparison → · Vapi review →
2. ElevenLabs Agents
Among the 31 voice ai tools we track, ElevenLabs Agents has the 4th-widest language coverage and the 3rd-lowest latency - a fit for multilingual and localization projects and real-time, conversational apps.
Head-to-head, ElevenLabs Agents takes no-code agency deploys, custom pipeline control and smb receptionist and booking from OpenAI Realtime API and matches it for healthcare compliance and outbound sales campaigns.
Before switching, weigh what stays behind - OpenAI Realtime API vs ElevenLabs Agents: adds native sip trunking.
Its published rate is $0.05 per minute, verified July 2026.
Why teams switch: For a no-code agency deploying and reselling voice AI, the ability to build agents without coding is essential. ElevenLabs Agents explicitly offers a no-code agent builder, while the OpenAI Realtime API is API-first with no no-code builder available. That single difference is decisive for this use case. ElevenLabs Agents also charges $0 per month in platform fees, whereas no platform fee information is available for the OpenAI Realtime API. Production cost for ElevenLabs Agents runs at $0.05 per minute. Neither tool publishes white-label or sub-account details, so that factor cannot decide the comparison. ElevenLabs Agents also supports 70 languages, broadening resale potential. The no-code builder alone, the single most important capability for a non-technical agency, tips this clearly toward ElevenLabs Agents.
No-code agency deploys verdict →
Overall verdict: ElevenLabs Agents wins three use cases outright and ties the remaining two, giving it a clear overall lead. For no-code agency deploys and SMB receptionist work, its built-in no-code agent builder lets teams launch without writing code, while a free plan with 10k credits per month and a $0 monthly platform fee lower the barrier to entry dramatically. At $0.05/min it is straightforward to budget, and no annual contract is required. For custom pipeline control, its API-first architecture combined with support for 70 languages and a 75 ms median end-to-end latency gives developers a fast, flexible foundation. OpenAI Realtime API cannot bring its own TTS voice or a third-party LLM, limiting customization for teams that want those options.
| Monthly volume | All-in monthly bill |
|---|---|
| 1K min/moSolo builder | $50 |
| 10K min/moAgency | $500 |
| 100K min/moCall center | $5,000 |
≈ $0.05 per minute all-in (est.), verified Jul 15, 2026. All-in monthly: platform fee + per-minute + telephony. Assumes GPT-4o class model, ElevenLabs voice. How we compute costs →
Full ElevenLabs Agents vs OpenAI Realtime API comparison → · ElevenLabs Agents review →
3. Google Gemini Live API
Among the 31 voice ai tools we track, Google Gemini Live API has the 4th-widest language coverage and the 5th-cheapest per-minute rate - a fit for multilingual and localization projects and cost-sensitive, high-volume work.
In our published verdicts, Google Gemini Live API matches OpenAI Realtime API for no-code agency deploys, healthcare compliance and smb receptionist and booking.
Before switching, weigh what stays behind - OpenAI Realtime API vs Google Gemini Live API: adds native sip trunking.
Its published rate is $0.018 per minute, verified July 2026.
Overall verdict: OpenAI Realtime API claims three outright wins across custom pipeline control, ecommerce support, and outbound sales campaigns, while Google Gemini Live API wins none. A decisive structural advantage is native SIP trunking support, which Google Gemini Live API lacks entirely. SIP trunking lets teams connect existing telephony infrastructure directly, making outbound sales campaigns and ecommerce support deployments far simpler to build and operate. On custom pipeline control, OpenAI Realtime API's native WebRTC, WebSocket, and SIP integration paths alongside MCP and tool calling give developers precise control over call flow that LiveKit or Pipecat middleware layers cannot fully replicate. Google Gemini Live API's $0.018/min base rate and 70-language support are genuine strengths, but they did not translate into a single outright win.
| Monthly volume | All-in monthly bill |
|---|---|
| 1K min/moSolo builder | $18 |
| 10K min/moAgency | $180 |
| 100K min/moCall center | $1,800 |
≈ $0.018 per minute all-in (est.), verified Jul 30, 2026. All-in monthly: platform fee + per-minute + telephony. Assumes GPT-4o class model, ElevenLabs voice. How we compute costs →
Full Google Gemini Live API vs OpenAI Realtime API comparison → · Google Gemini Live API review →
4. Hume EVI
Among the 17 voice ai tools we track, Hume EVI has the 6th-lowest latency - a fit for real-time, conversational apps.
In our published verdicts, Hume EVI beats OpenAI Realtime API for no-code agency deploys, custom pipeline control, healthcare compliance and smb receptionist and booking and matches it for ecommerce support and orders and outbound sales campaigns.
The reverse angle matters too - OpenAI Realtime API vs Hume EVI: adds native sip trunking.
Published pricing starts at $0.07 per minute, verified July 2026.
Why teams switch: For engineering teams building custom pipelines, the two most critical capabilities are bring-your-own LLM and full API-first control. Hume EVI supports bring-your-own LLM while OpenAI Realtime API does not, locking teams into a single model. Both are fully API-first. Hume EVI also allows bring-your-own TTS voice, giving teams complete control over the audio stack, whereas OpenAI Realtime API does not. Hume EVI's vendor-claimed 300 ms median end-to-end latency is competitive. These two stack-control advantages are decisive for custom pipeline work.
Custom pipeline control verdict →
Full Hume EVI vs OpenAI Realtime API comparison → · Hume EVI review →
5. Abby Connect
Among the 31 voice ai tools we track, Abby Connect has the 28th-widest language coverage.
Before switching, weigh what stays behind - OpenAI Realtime API vs Abby Connect: adds native sip trunking.
6. Air AI
Seen from the other side, OpenAI Realtime API vs Air AI: adds native sip trunking.