GPT-Live-1 vs Gemini 3.8 TTS: Jeden prowadzi rozmowę, drugi odczytuje skrypt — a tylko jeden z nich jest tani

Set G​PT-Live-1 and Gemini 3.8 Flash TTS next to each other on a per-minute meter and the answer looks obvious. G​oogle's narrator bills about 1.35 cents per minute of generated speech at the 2026 rate. O​penAI's conversational model bills 5 cents per minute of open line — and keeps billing while the backend thinks, while the user pauses, and while nothing is being said at all. Roughly a twenty-seven-fold gap, before anyone has asked whether the two are doing the same job.

They are not, and in a way that is more interesting than the usual "different categories" hand-wave. Gemini 3.8 Flash TTS cannot hear. G​PT-Live-1 cannot be batched. And the naming makes this worse than it needs to be, because the phrase G​emini 3.8 TTS — the label half the internet is using — does not correspond to any model you can call.

Najpierw problem z nazwą, ponieważ to on decyduje o cenie, którą podajesz.

There is no model called G​emini 3.8 TTS. G​oogle's own documentation uses the phrase as umbrella language for two callable endpoints, and they are priced differently enough that quoting the wrong one is a real error:

• gemini-3.8-flash-tts — pełny poziom, ponad 130 języków, 0,50 USD za milion tokenów tekstu na wejściu i 9,00 USD za milion tokenów audio na wyjściu, a od 1 stycznia 2027 r. odpowiednio 1,00 USD i 18,00 USD.

• gemini-3.8-flash-lite-tts — 101 języków, taka sama stawka za dane wejściowe, 6,00 USD za milion wyjściowych tokenów audio, wzrastająca do 12,00 USD.

• Oba mają stawki Batch i Flex w wysokości połowy ceny Standard (0,25 USD za wejście, 4,50 USD lub 3,00 USD za wyjście) oraz stawki Priority na poziomie 1,8× (0,90 USD za wejście, 16,20 USD lub 10,80 USD za wyjście).

Audio jest rozliczane po 25 tokenów na sekundę i stąd bierze się stawka za minutę: 25 tokenów × 60 sekund = 1500 tokenów audio na minutę, więc 9,00 USD za milion daje około 0,0135 USD na minutę. Flash-Lite wypada blisko 0,009 USD.

The status of the model is genuinely unsettled and worth saying out loud, because G​oogle's own surfaces disagree. The G​emini API changelog calls both models generally available. The API model list labels them "New Stable." G​oogle Cloud's text-to-speech documentation describes them as available in Preview through the G​emini Enterprise API only. The announcement blog post, published on 23 September 2026, uses neither word. Anyone writing a procurement note this month should treat the GA label as the changelog's claim rather than a settled fact.

Co faktycznie robi każdy model, gdy go wywołasz

Gemini 3.8 Flash TTS przyjmuje tekst i zwraca dźwięk. Nie ma wejścia audio, nie ma tury do przejęcia, nie ma pojęcia bycia przerwanym ani transkrypcji do zwrócenia, bo nigdy niczego nie słyszał. Endpoint unarny zwraca WAV w 24 kHz mono; strumieniowanie zwraca pozbawiony nagłówka 16-bitowy PCM, przy czym akceptowane są mulaw i alaw oraz konfigurowalna częstotliwość próbkowania. Wskazówki sceniczne w tekście są zapisywane w skrypcie jako zdarzenia w nawiasach kątowych — <laugh>, <sigh>, <breath>, <short pause> — a tekst wejściowy jest poza tym traktowany jako dosłowna transkrypcja, a nie jako instrukcje. Live API w ogóle nie obsługuje tych modeli.

G​PT-Live-1 does the opposite job. It is full duplex: it processes incoming audio while producing outgoing audio, decides several times a second whether the user has finished talking, and returns speech-recognition transcripts as part of the session. Its inputs are audio and text; its outputs are audio and text; images and video are unsupported. It streams and supports function calling but not structured outputs, and knowledge cut-off is 31 July 2025. Only one endpoint serves it — v1/live/sessions — and Chat Completions, Responses, Realtime and Batch are all out.

That last detail is the one that ends the comparison for a lot of workloads. If your product renders a script, G​PT-Live-1 is neither the cheap option nor the correct one. If your product answers a phone, Gemini 3.8 Flash TTS is one third of a pipeline that still needs an ASR model and a language model bolted on either side — and the whole point of G​PT-Live-1 is that the seam between those three parts is where conversations break.

Liczby i do kogo należą

On Artificial Analysis's Provider Voice Arena — a blind-vote Elo board over each vendor's own native voices — G​oogle's new models land mid-field rather than at the top:

• Gemini 3.8 Flash TTS — Elo 1275 na 5. pozycji, z 95-procentowym przedziałem od około 1260 do 1290 na 2783 próbkach, wyceniany na 16,5 USD za milion znaków.

• Gemini 3.8 Flash-Lite TTS — Elo 1 248 na 8. miejscu, przedział w przybliżeniu od 1 234 do 1 262, 11,0 USD za milion znaków.

• Above both — Eleven v4 Turbo at 1,330, Eleven v4 at 1,329, Q​wen-Audio-3.1-TTS-Plus at 1,296 and Cartesia Sonic 3.6 at 1,285.

G​oogle's own claim is stronger than that board, and it is a vendor claim: the 23 September post says the models took first place on Hume AI's Voice Design Benchmark at 71.4 and led Hume's accent modelling at 60.8, plus top blind-preference positions in Japanese, Brazilian Portuguese, Vietnamese, Modern Standard Arabic, Mexican Spanish and Hindi. Those are G​oogle-reported placements on someone else's evaluation, not a reproduction.

Flipping to the conversational side, G​PT-Live-1's numbers come from a different board entirely. Artificial Analysis's speech-to-speech index — a weighted average of speech reasoning, agentic performance, arena preference and task success — now lists G​PT-Live-1 under named backend configurations rather than as one row: G​PT-Live-1 (Astra, medium) and G​PT-Live-1 (Sol, low) sit at the top of that index, with G​rok Voice 3.0 leading the field. That is a useful reminder that in this architecture the voice model is only half the row; the delegated backend moves the score.

One number that matters and does not exist anywhere: G​oogle publishes no official latency figure for either TTS model. Every time-to-first-audio number in circulation is third-party — one aggregator's p50 sits around 3.47 seconds for Flash TTS and 2.66 for Flash-Lite — and none of it is directly comparable to G​PT-Live-1's conversational cadence, because they measure different things.

Projektowanie głosu to punkt, w którym te dwie rzeczy się spotykają, i zarazem punkt, w którym znów się rozchodzą

Obaj dostawcy pozwalają teraz opisać głos słowami. To nowość w 2026 roku i to najbliżej, jak te dwa produkty zbliżają się do nakładania się na siebie.

G​oogle's path runs through the G​emini API: a prompt-based voice persona saved persistently as a voice_ ID, voice replication from about a 30-second sample with a consent check, SynthID watermarking and C2PA credentials attached, and a cap of 200 stateful custom voices per project with one-year retention from last use. The written description covers role, accent and vocal traits.

O​penAI's path, released on 16 October 2026 to all API customers, is a POST to /v1/audio/voices with type: "prompt", a name, the description and "model": "auto". Creation is free; using the voice bills at normal session rates. It returns metadata only — no audio, no preview. The qualities you can steer are accent, age, presentation, pitch, timbre, texture, loudness, speech rate and distinctiveness, all expressed as ordinary language with no numeric parameters.

Dwie różnice decydują o tym, której z nich możesz faktycznie użyć:

• Prompt-generated voices on G​PT-Live work only with G​PT-Live. They are explicitly incompatible with the Text to Speech, Realtime and Chat Completions APIs. G​oogle's custom voices are, by contrast, voices for a rendering engine, which is what makes them reusable across a catalogue.

• The organisation cap on O​penAI's side is 100 prompt-generated voices, and it applies to voices generated on behalf of your customers too. G​oogle's ceiling is 200 per project. If you are a platform minting a voice per customer, both numbers are your real product limit, not a footnote.

There is also a difference in what you get back. A G​oogle voice arrives with SynthID and C2PA provenance attached. An O​penAI prompt-generated voice arrives as an ID, a creation timestamp and your own prompt text — and the documentation says outright that generated voices are not guaranteed to be unique. Keep the description under version control; it is the only record of what you asked for.

Gdzie różnica cenowa przestaje wynosić 27×

The per-minute comparison is the one that gets quoted and it is the one that misleads, because G​PT-Live-1's meter is not measuring the same resource. Three things move the real ratio:

• Idle time is billable. A voice session is billed per second for as long as it is open, including while the backend model is working and while the user is silent. G​oogle's meter only advances when audio is generated. A support call where the user talks for four minutes and your backend thinks for two is six billable minutes on Live and fewer on the renderer — before you have counted the ASR and language-model legs the renderer still needs.

• Długość danych wyjściowych można kontrolować tylko w jednym przypadku. Zadanie renderowania jest znaną wielkością: możesz wycenić artykuł o długości 900 słów, zanim go wygenerujesz, a stawki Batch zmniejszają ją jeszcze o połowę. W przypadku rozmowy nie jest to możliwe.

• The backend is a separate bill. Delegated reasoning and tool use on G​PT-Live-1 are charged at normal model rates on top of the $0.05 a minute, and O​penAI's own cost guidance frames the lever as making the user finish sooner — for example, running a faster backend with parallel tool calls so the conversation ends a minute earlier, saving $0.05. The voice rate is fixed; the session length is the dial.

That last point is where a routing layer stops being a nice-to-have. Client delegation lets you point a G​PT-Live session at your own agent or service, which means the delegated backend can be any model — and the useful version of "any model" is one endpoint and one key rather than a contract per provider. OrcaRouter fronts 200-plus models at provider list price with no markup, so a vendor price cut on the backend side reaches you the day it lands, and automatic failover covers a provider outage without the caller hearing it. If you are building the delegated path, the backend choice is where your cost actually lives; the $0.05 a minute is a constant.

To be precise about the boundary: OrcaRouter does not host G​PT-Live-1 or the G​emini 3.8 TTS models. What it routes is the reasoning side of a delegated Live session.

Po który sięgnąć?

If you are rendering — articles, documentation, video narration, IVR prompts written in advance — Gemini 3.8 Flash TTS is the correct tool and G​PT-Live-1 is roughly 27 times too expensive per audio minute and structurally incapable of the job in batch. Take Flash-Lite if 101 languages cover you, take Batch or Flex rates if latency is not the constraint, and model the January 2027 price doubling from the start, because G​oogle has published it in the same table rather than burying it.

Jeśli prowadzisz rozmowę, porównywanie TTS to błąd kategorii, a uczciwe pytanie brzmi inaczej: czy delegowany backend generuje odpowiedź na tyle szybko, że sesja pozostaje krótka. To właśnie ta liczba decyduje o wysokości twojego rachunku i to ona nie trafia na żaden slajd z premiery.

And if you are simply trying to work out what "G​emini 3.8 TTS" costs — the answer is $9.00 per million audio tokens, on one of the two models that name refers to, until the end of 2026.

Nic z tego nie jest hipotetyczne: udokumentowane awarie AI i incydenty z agentami stojące za takimi wydaniami jak to są zebrane w the OrcaRouter AI Incident Archive, gdzie każdy wpis zawiera własne źródła, stopień ważności, ocenę pewności i oznaczenie sporne.