Omnia Voice vs OpenAI Realtime

OpenAI's Realtime API is a strong piece of engineering with the model quality you would expect. For prototyping a voice experience quickly, it is hard to beat.

It is also completely hosted, on their infrastructure, with their models, at their prices. Every difference on this page follows from that.

Choose OpenAI Realtime if

• You want the fastest possible path from idea to a talking prototype
• Their model quality is your primary criterion
• You are already deep in their ecosystem
• Hosted-only is not a constraint for you

Choose Omnia if

• You cannot send audio to a third-party US API — regulator, DPO, or customer contract
• You want to run it yourself, on your own infrastructure or on-premise
• You want telephony you own rather than an integration you assemble
• You want a per-minute cost that does not change when a vendor reprices

---

One system, not an assembly

Omnia connects audio directly to the reasoning layer. There is no speech-to-text stage in the middle, which is where the round-trip time goes and where nuance gets dropped. One design decision, two consequences worth having:

Speed. About 250 milliseconds to first response, because processing starts while the caller is still speaking rather than after a transcript is finished.

Robustness. Accents, proper nouns, and callers who switch language mid-sentence survive, because there is no transcription step to flatten them first. That is what 50+ languages means in practice — not a list on a pricing page, but comprehension over a narrowband phone line, at conversational pace.

Agents that act

An agent that talks well and cannot do anything is an answering machine. Ours call your systems mid-conversation, with credentials encrypted at rest and never returned by the API, static parameters the model never sees, read-only lookups run eagerly so they do not become dead air, and a deferred pattern for work that cannot finish inside a timeout without stranding the caller.

Hosted-only is the constraint

You cannot self-host the Realtime API. You cannot bring your own models. You cannot keep the audio inside the EU as a guarantee rather than a configuration. Those are not gaps in the product, they are what the product is.

For a lot of teams that is completely fine. For a Finnish healthcare provider, a bank, or a public-sector body, it ends the conversation before features are discussed.

Omnia runs three ways on the same API — our cloud, dedicated capacity, or entirely your own infrastructure. Moving between them does not change your integration code.

And self-hosting is an exit route as much as a deployment choice. If we were acquired or changed direction, a self-hosted customer keeps running. You cannot be orphaned by us. A hosted-only API cannot offer that, by construction.

Telephony

Realtime gives you a real-time audio API. Putting it on a phone line is work you do — a carrier, a media bridge, and the glue between them.

Omnia treats the phone as a first-class case. Assign a number and an agent answers it, or bring your own carrier — Twilio, Telnyx, Plivo, or a SIP trunk — and stream to a WebSocket we hand you. Your phone bill stays yours, at your rates, unresold.

Cost

Per minute of conversation, in one number, on a rate you can forecast. Hosted model pricing is set by the vendor and changes when they decide it does.

The first two rates are self-serve: sign up and start. The volume rate is negotiated rather than unlocked automatically, so talk to us if you are running at scale.

Where it runs

Cloud, dedicated GPU capacity, or entirely your own infrastructure — the same API across all three, so moving does not change your integration code. EU data residency is the default rather than a configuration.

Self-hosting is also an exit route, not only a deployment preference. If we were acquired, pivoted, or sunset a service, a self-hosted customer keeps running. You cannot be orphaned by us.

Who runs this

Veikkaus, Elisa, Eltel Networks and MySpeaker run on Omnia in production, and our partners deliver it for their own clients — Nitor for Finnair, Posti and OP Financial Group; Houston Inc. for Telia and Wärtsilä. Setera provides the telephony layer beneath, across more than fifty countries.

Side by side

The honest summary

If you are prototyping and hosting is not a constraint, use Realtime — it will be quicker and the models are excellent.

If you are shipping something that has to run in the EU, or on your own hardware, or on a phone line, or at a cost you can put in a forecast, that is where this becomes a different conversation.