OpenAI Realtime API Alternatives (2026): 5 Compared
5 real alternatives to OpenAI Realtime API, the raw speech-to-speech model API: LiveKit Agents, Vapi, Deepgram Voice Agent API, Retell AI and ElevenLabs Conversational AI, each answering a different documented reason teams look for a switch -- verified against this site's own researched listings.
OpenAI Realtime API's real strength is being a raw model API and nothing more: WebRTC for browser and mobile clients, WebSocket for server-side pipelines, native SIP for telephony, all billed purely on audio and text tokens with no platform fee layered on top -- genuinely the leanest way to get speech-to-speech if you are willing to build the application logic around it yourself.
That leanness is also what a switcher is usually reacting to: there is no built-in call-flow orchestration, no turn-management or tool-calling scaffolding, and no telephony provider integration beyond raw SIP -- you manage the conversation lifecycle in your own code, and you are using OpenAI's own models exclusively.
None of that makes OpenAI Realtime API wrong -- if you want the cheapest, most transparent per-token bill and are building your own orchestration layer anyway, that is exactly the job it does. Stay with OpenAI Realtime API if you want a pure model API with transparent per-token billing and are comfortable building the call-orchestration layer yourself.
Move if you want that orchestration layer built for you, provider flexibility instead of being locked to OpenAI's own models, compliance-grade deployment options, a phone-telephony specialist with SIP trunking handled, or voice quality and cloning decoupled from model choice entirely.
The five tools below are independently researched, Published listings on this site: each carries current positioning and pricing we verified directly against the vendor, and an honest best-for call.
On this page
How we chose these alternatives
We only draw alternatives from this site's own Published, individually-researched listings, never a fresh, unverified list. OpenAI Realtime API's own 10-listing voice agent category was checked for genuinely distinct switching reasons rather than named on volume: the five below were picked specifically because each answers a different documented reason a reader leaves OpenAI Realtime API -- wanting the orchestration layer built in, provider flexibility instead of OpenAI-only models, compliance-grade deployment options, phone-telephony handled for you, or voice quality and cloning as the deciding factor. Every price and platform claim below was checked live against the vendor's own site on 2026-08-20.
How OpenAI Realtime API and its alternatives compare
| Feature | LiveKit Agents | Vapi | Deepgram Voice Agent API | Retell AI | ElevenLabs Conversational AI |
|---|---|---|---|---|---|
| Description | The Apache 2.0 voice-agent framework. 13.1k GitHub stars, self-hostable, and the only open-source pick in this category with fully published pricing. | The developer platform for voice AI agents, bring your own model, voice and telephony, and Vapi orchestrates the call. | The speech-infrastructure vendor's own voice-agent API. Managed STT, LLM and TTS over a single WebSocket, $4.50/hr flat, with 6 LLM providers and self-hosted or VPC deployment on the same product. | Build phone-call voice agents on Retell's turn-taking layer, plug in your own LLM, voice, and telephony, ship over voice, chat, or SMS. | The voice-quality specialist’s own agent layer, 10,000+ voices and instant cloning, with a bring-your-own-LLM brain. |
| Category | Voice agents | Voice agents | Voice agents | Voice agents | Voice agents, Agent platforms |
| From | $0 / month | $0.05 / min | $4.50/hr Standard / Standard to Custom (BYO LLM and TTS) | $0.07–$0.31 / min | $0 / mo |
| Tier | Listed | Listed | Listed | Listed | Listed |
| API | Yes | Yes | Yes | Yes | Yes |
| Tags |
The digest
Done comparing? Watch the field move. Which agents actually ship, one short email, every Tuesday.
5 alternatives to OpenAI Realtime API
LiveKit Agents
from $0 / monthThe Apache 2.0 voice-agent framework. 13.1k GitHub stars, self-hostable, and the only open-source pick in this category with fully published pricing.
Best forEngineering teams that want to own their voice-agent stack end to end, self-hosted or on LiveKit Cloud, without being locked into one vendor's API.
For the reader who wants provider flexibility and self-hosted control instead of being locked to OpenAI's own models. LiveKit's own site confirms the Agents SDK is open source (Apache 2.0), self-hostable, and provider-agnostic -- swap STT, LLM and TTS providers through a plugin system without rewriting agent logic -- and is the infrastructure behind ChatGPT's own Advanced Voice Mode. Component pricing runs roughly $0.05-$0.30/minute at scale depending on providers chosen. The tradeoff: you assemble and operate the pipeline yourself, there is no single managed bill.
Vapi
from $0.05 / minThe developer platform for voice AI agents, bring your own model, voice and telephony, and Vapi orchestrates the call.
Best forEngineering teams that want maximum control to build custom voice agents on their own choice of model, voice and telephony.
For the reader who wants the call-orchestration layer built for them instead of hand-rolling it against a raw model API. Vapi's own site confirms a unified platform for voice, conversation flow, telephony and integrations, with its own pricing page confirming a Build plan at $0.05/minute (60+ minutes included, model costs passed through at provider rates, $10/month per additional concurrent line) and an annual Scale plan for volume. The tradeoff: a per-minute platform fee on top of model costs, versus OpenAI's raw audio-token-only billing.
Deepgram Voice Agent API
from $4.50/hr Standard / Standard to Custom (BYO LLM and TTS)The speech-infrastructure vendor's own voice-agent API. Managed STT, LLM and TTS over a single WebSocket, $4.50/hr flat, with 6 LLM providers and self-hosted or VPC deployment on the same product.
Best forEngineering teams that want a managed speech pipeline with real LLM-provider choice, and regulated enterprises that need a self-hosted or VPC deployment option a typical closed-source voice-agent vendor does not offer.
For the reader who wants multi-provider flexibility with compliance-grade deployment options. Deepgram's own site confirms bring-your-own-LLM or TTS while keeping Deepgram's orchestration and streaming pipeline, deployable fully managed, single-tenant, in VPC, or fully self-hosted for HIPAA, GDPR and data-residency needs, at a flat $4.50/hour with the full stack. The tradeoff: a flat hourly rate rather than OpenAI's pure per-token metering.
Retell AI
from $0.07–$0.31 / minBuild phone-call voice agents on Retell's turn-taking layer, plug in your own LLM, voice, and telephony, ship over voice, chat, or SMS.
Best forProduct and engineering teams that want a low-latency, human-sounding phone agent with flexible model and telephony choice.
For the reader who wants a phone-telephony specialist instead of raw SIP. Retell's own site confirms SIP trunking to any telephony provider (Twilio, Vonage, or existing numbers), with its own pricing page confirming pay-as-you-go billing, $10 in free credit, $0.07-$0.31/minute for voice agents, and 20 free concurrent calls. The tradeoff: a real per-minute premium over OpenAI's raw audio-token rate, since call orchestration and telephony are bundled in.
ElevenLabs Conversational AI
from $0 / moThe voice-quality specialist’s own agent layer, 10,000+ voices and instant cloning, with a bring-your-own-LLM brain.
Best forDevelopers and product teams who want ElevenLabs' voice quality and cloning as the foundation of their agent, and are comfortable assembling the rest of the stack themselves.
For the reader whose actual constraint is voice quality and cloning, not the model. ElevenLabs' own documentation confirms bring-your-own-LLM across OpenAI, Anthropic, Google Gemini or a custom endpoint, plus 10,000+ voices with instant cloning. The tradeoff: no public self-serve pricing to compare against OpenAI's transparent per-token rate -- ElevenLabs is sales-led.
Advertisement
Sponsor this page. Alternatives pages are read by buyers actively choosing an agent, first-party inventory, clearly labelled, sold by the week.
Sponsor this page →Featured · top of your category →Frequently asked questions
- What is the closest OpenAI Realtime API alternative if I want to avoid vendor lock-in?
- LiveKit Agents -- its own site confirms an open-source (Apache 2.0), self-hostable, provider-agnostic framework that swaps STT, LLM and TTS providers through a plugin system, and is the infrastructure behind ChatGPT's own Advanced Voice Mode.
- Is there an OpenAI Realtime API alternative that handles call orchestration for me?
- Vapi -- confirmed on its own site as a unified orchestration platform for voice, conversation flow and telephony, with a Build plan at $0.05/minute (60+ minutes included) and an annual Scale plan for volume.
- Which OpenAI Realtime API alternative offers self-hosted or VPC deployment for compliance?
- Deepgram Voice Agent API -- its own site confirms fully managed, single-tenant, VPC or fully self-hosted deployment for HIPAA, GDPR and data-residency needs, at a flat $4.50/hour with the full stack.
- What is the best OpenAI Realtime API alternative for phone-based voice agents?
- Retell AI -- confirmed on its own site as a phone-specific platform with SIP trunking to any telephony provider, pay-as-you-go pricing from $0.07-$0.31/minute after $10 in free credit.
- Which OpenAI Realtime API alternative is best if voice quality and cloning matter more than the model?
- ElevenLabs Conversational AI -- its own documentation confirms bring-your-own-LLM across OpenAI, Anthropic, Google Gemini or a custom endpoint, plus 10,000+ voices with instant cloning; pricing is sales-led with no public self-serve tier.
Where next? Back to the full research, deeper into the category, or get your own agent into the index.
Get a quote from OpenAI Realtime API or an alternative
Tell us what you need. We make the introduction to OpenAI Realtime API.