Summary
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OpenAI and Google now both offer dedicated models for real-time speech-to-speech translation: OpenAI’s GPT-Realtime-Translate and Google’s Gemini 3.5 Live Translate.
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Their model pricing is now remarkably close. OpenAI lists GPT-Realtime-Translate at $0.034 per minute, while Google puts Gemini 3.5 Live Translate at an effective price of roughly $0.0368 per minute.
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Their biggest practical difference is language coverage. OpenAI supports more than 70 input languages but currently translates into 13 output languages. Gemini supports real-time translation across more than 70 languages.
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Both can now be connected to real phone calls. What neither provides by itself is the complete telephony layer around the model: participant routing, call control, human handoffs, continuity, monitoring, failure handling and the rest of the infrastructure required to operate translation on real business calls.
This piece compares what each one offers today, where they genuinely differ, and what businesses should look at beyond the model itself.
What are OpenAI and Gemini Live APIs?
Voice AI has moved quickly in 2026. OpenAI’s general Realtime API is currently led by GPT-Realtime-2.1, a speech-to-speech model built for voice agents, reasoning and tool use. But that is no longer the most relevant OpenAI product to compare for translation.
In May 2026, OpenAI released GPT-Realtime-Translate, a model built specifically for continuous speech-to-speech translation. Instead of waiting for conventional conversational turns, it can process incoming speech and begin returning translated audio while the speaker is still talking.
Google followed in June with Gemini 3.5 Live Translate, its dedicated low-latency speech translation model. It also processes speech continuously rather than behaving like a conventional turn-based AI assistant. As of August 2026, the model is available to developers in public preview through the Gemini Live API.
That distinction matters. A year ago, the question was whether a general-purpose realtime voice model could be prompted into working as a translator. Now both companies have separated the problem. They have voice-agent models for conversations with AI, and dedicated translation models for conversations between people.
The business question has moved with them. It is no longer simply, “Can this model translate a live conversation?” It is, “What happens when that translation has to operate inside an actual business call?”
Where OpenAI and Gemini differ
01. Cost
The cost difference is much smaller than it used to be. OpenAI currently prices GPT-Realtime-Translate at $0.034 per minute.
Google prices Gemini 3.5 Live Translate at $3.50 per million audio input tokens and $21 per million audio output tokens. Google estimates that at roughly $0.0368 per minute for input and output audio combined.
So, at current list pricing, there is no longer a meaningful 10x or 100x cost difference between the dedicated translation products. For a small prototype, the difference is negligible.
For a business running millions of call minutes, every fraction still matters, but the model price is only one part of the calculation. Telephony, media streaming, transcription, infrastructure and the rest of the call path also have to be included. Cost alone is no longer the obvious reason to choose one over the other.
02. Language coverage
This is where the difference is much clearer. OpenAI’s GPT-Realtime-Translate accepts speech in more than 70 input languages, but currently produces translated speech in 13 output languages: English, Spanish, Portuguese, French, Japanese, Russian, Chinese, German, Korean, Hindi, Indonesian, Vietnamese and Italian.
Gemini 3.5 Live Translate supports real-time translation across more than 70 languages. That gives Gemini substantially broader target-language coverage today. Google also exposes some regional language variants separately. Portuguese, for example, is listed as both Portuguese (Brazil) and Portuguese (Portugal).
But language coverage is not the same thing as dialect accuracy. Neither provider publishes comprehensive accuracy results for every dialect, accent and language combination it supports.
Google itself notes that language detection can struggle with heavy accents, closely related languages and rapid language switching. OpenAI’s production guidance similarly recommends testing terminology, names, domain-specific language and real production audio directly rather than assuming performance from a supported-language list. For Portuguese, Arabic and Spanish speakers, for example, the language name alone still does not tell you how the system will perform with the people actually making your calls.
03. Product maturity
There is another difference worth paying attention to because these products are new. OpenAI released GPT-Realtime-Translate on 7 May 2026. Google released Gemini 3.5 Live Translate on 9 June 2026 and, as of this update, still labels the developer model as Preview.
That does not make one automatically better than the other. It does mean businesses should be careful about treating either product category as settled infrastructure.
The dedicated live translation market has changed materially in the space of a few months, and the surrounding realtime voice models are moving just as quickly. OpenAI, for example, released GPT-Realtime-2.1 in July with improvements to noise handling, interruptions and alphanumeric recognition. What you evaluate today may not be the same product you evaluated six months ago.
The question neither one answers
Here’s the part that still doesn’t show up in a simple feature comparison. Both APIs can now be used in real phone-call architectures.
OpenAI publishes an implementation for connecting GPT-Realtime-Translate to Twilio phone calls through Media Streams. Its broader Realtime platform also supports SIP calls and call referral. Google’s Live API works over WebSockets, and Google now publishes telephony reference implementations and integrations for connecting Live models to phone infrastructure such as Twilio and other communications platforms.
So it is no longer accurate to say either technology is limited to a browser or app. But connecting a translation model to a phone call and operating live translation as part of a production telephony system are two different things. The model still needs something around it.
For a two-person translated phone call, someone has to receive the audio from each participant, keep those audio streams separate, send them through the correct translation sessions and route the translated audio back to the right person. For larger calls, that routing gets more complicated again.
Then there is call state.
What happens if someone is put on hold?
What happens if another participant joins?
What happens when the AI agent transfers the caller to a human?
What happens if one model session disconnects but the phone call is still running?
What happens if the customer changes language halfway through the call?
What happens when the model returns the wrong name, number or industry-specific term? OpenAI and Google give developers increasingly capable translation engines and the interfaces required to connect them to other systems. They do not operate the complete call environment for you.
And that distinction becomes important when live translation moves from a demo into a call centre, telecom network or customer-support operation.
What happens during an AI-to-human handoff?
This is one area where the market has moved enough that the distinction needs to be precise. A human can take over a call that started with AI. OpenAI’s broader Realtime platform even includes SIP call referral, and external telephony platforms can manage transfers independently of either AI model.
The problem is not whether a transfer is technically possible. The question is what happens to the translation when that transfer happens.
If translation only exists inside the AI agent’s model session, ending or replacing that session can end the translation with it. If translation is instead part of the call’s media path, it can remain active while the participants change.
That is an architecture decision outside the translation model itself. For many voice AI use cases, this distinction does not matter. For business translation, it often does.
What to ask before choosing either one
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Are you building a translator or an AI agent? These are now different products. If the job is translating one person to another, evaluate GPT-Realtime-Translate and Gemini 3.5 Live Translate. If the AI itself needs to reason, use tools, answer questions and take actions, you are evaluating the general Realtime or Live agent models instead.
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Does the model support both sides of the language pair you need? Do not stop at the number of supported languages. OpenAI can understand more than 70 input languages but only produces translated speech in 13 output languages today. Check the source language, the target language and the actual dialect your callers use.
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What happens when the call changes? If an AI agent hands the caller to a person, another participant joins or the call is transferred elsewhere, work out who still owns the translation path. A model API does not make translation continuity automatic.
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How does it perform on your actual calls? Test accents, background noise, overlapping speech, names, numbers, industry terminology and callers who move between languages. A supported-language list is not an accuracy guarantee.
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What does the complete deployment look like? Model the total cost, not just the model token or per-minute price. Then look at the complete data path: where the phone call enters the system, where the audio is processed, what is retained, which regional controls apply and what happens during failures or reconnects.
Both OpenAI and Google now provide meaningful enterprise data controls. Those controls still depend on the product, tier and configuration you use, and they do not replace the need to understand the rest of your telephony architecture.
Is there another option?
Yes, but it is useful to be clear about what the alternative actually is. SentiVue does not compete with OpenAI and Google by trying to be another general-purpose model API. In many of our deployments, one of these providers can still be doing the underlying speech-to-speech work.
We sit above and around that model layer. SentiVue attaches translation to the call itself, rather than making the AI agent session the centre of the architecture. That means the translation can remain in the media path when an AI agent hands the conversation to a human.
That is combined with dialect-specific models trained on native speech data, including European Portuguese and Egyptian Arabic, and telephony infrastructure built for real call environments.
The difference matters more now than it did a year ago. OpenAI and Google are getting very good at the model layer. Our job is not to pretend those models are weak. It is to make them usable in the environments where a model alone is not enough: telecoms, call centres and customer-support operations where calls transfer, participants change, data has to stay in the right place and translation cannot disappear because one AI session ended.
If you’re evaluating OpenAI or Gemini for a translation use case, send us a message or book a free consultation to find out how we might help.
OpenAI Realtime Translate vs Gemini Live Translate vs SentiVue
FeatureOpenAI GPT-Realtime-TranslateGemini 3.5 Live TranslateSentiVueWhat it isDedicated streaming speech-to-speech translation model.Dedicated low-latency speech-to-speech translation model.Live translation and voice AI infrastructure layer.Current statusAvailable through Realtime Translation API (May 2026).Public Preview (June 2026).Production ready.Model pricing$0.034 per minute.Approximately $0.0368 per minute.Deployment pricing.Language coverage70+ input / 13 output languages.70+ languages (input and output).70+ languages.DialectsNo public dialect benchmarks.Exposes some regional variants (e.g. Brazil/Portugal).Dialect-specific models (e.g. European Portuguese).TelephonyIntegrated via Media Streams/SIP.Integrated via WebSockets/telephony platforms.Built for live telephony environments.HandoffPossible, but continuity not automatic.Possible, but continuity not automatic.Designed for AI-to-human continuity.Data controlsResidency and zero-retention options.Paid usage not used for training; zero-retention available.Defined data zones; zero retention by default.
Frequently Asked Questions
Should I use OpenAI or Gemini for real-time translation?
As of August 2026, price is no longer the main difference between them. OpenAI’s GPT-Realtime-Translate costs $0.034 per minute and supports more than 70 input languages, but only 13 output languages. Gemini 3.5 Live Translate works across more than 70 languages and therefore has much broader target-language coverage, although the developer model is still in public preview.
If both support the language pair you need, test them on your actual calls. The quality of a specific language pair, dialect, terminology and audio environment will usually matter more than a small difference in published model pricing. And if this is going onto real phone infrastructure, evaluate the telephony architecture separately from the translation model.
What’s the difference between GPT-Live and the OpenAI Realtime API?
GPT-Live is OpenAI’s newest full-duplex voice model family, launched in July 2026 and now powering the latest ChatGPT Voice experience. It can listen and speak at the same time rather than operating through conventional turns.
As of 25 August 2026, OpenAI says GPT-Live is planned for the API but has not yet made it generally available to developers there. The Realtime API is the developer-facing platform available today, with models such as GPT-Realtime-2.1 for voice agents and GPT-Realtime-Translate for dedicated live translation. For a business translation application today, GPT-Realtime-Translate is the relevant OpenAI product.
Is Gemini Live API cheaper than OpenAI’s Realtime API?
Not when comparing the current dedicated translation models. OpenAI lists GPT-Realtime-Translate at $0.034 per minute. Google estimates Gemini 3.5 Live Translate at approximately $0.0368 per minute for input and output audio combined. The two are now close enough that model pricing should usually be considered alongside language coverage, translation performance and total deployment cost rather than treated as the deciding factor on its own.
Can OpenAI or Gemini handle a call that transfers from AI to a human agent?
Yes, with the right surrounding architecture. A telephony platform can transfer the call independently of the model, and OpenAI’s broader Realtime platform also supports SIP call referral. What neither translation model does automatically is guarantee that the translation stays active after the AI agent leaves. For that, translation has to remain part of the call’s media path rather than being tied only to the AI agent session.
Do OpenAI and Gemini support specific dialects, or just general languages?
Both support multilingual speech, but a language being listed as supported does not prove equal performance across all of its dialects. Google explicitly distinguishes some regional language variants, including Portuguese for Brazil and Portugal. It also documents cases where heavy accents can affect language detection.
OpenAI says its translation model is designed to work with regional pronunciation and recommends direct production testing for terminology, names and difficult audio. Neither provider publishes comprehensive dialect-level accuracy benchmarks across all supported languages. If dialect performance matters to the call, test the dialect itself.



