--- type: AI Model id: gemini-voice title: Gemini Voice API provider: Google description: "Google's Gemini voice models on one endpoint pair: Gemini 3.5 Transcribe turns recorded speech into text with speaker labels and word-level timestamps across 85+ locales, and Gemini 3.1 Flash TTS turns text into speech with 30 voices, natural-language delivery control and two-speaker dialogue. Both are billed per minute of audio." resource: https://www.pixazo.ai/models/gemini-voice docs_url: https://www.pixazo.ai/models/gemini-voice trending: true latest_version: v3.5 tags: - trends - speech-to-text - text-to-speech - google variants: - id: gemini-3-5-transcribe-v1 name: Gemini 3.5 Transcribe version: 3.5 capabilities: - Speech to Text - id: gemini-3-1-flash-tts-v1 name: Gemini 3.1 Flash TTS version: 3.1 Flash capabilities: - Text to Speech timestamp: 2026-08-30T12:03:01.004Z --- # Gemini Voice API > Provider: **Google** > Source: https://www.pixazo.ai/models/gemini-voice Google's Gemini voice models on one endpoint pair: Gemini 3.5 Transcribe turns recorded speech into text with speaker labels and word-level timestamps across 85+ locales, and Gemini 3.1 Flash TTS turns text into speech with 30 voices, natural-language delivery control and two-speaker dialogue. Both are billed per minute of audio. ## Gemini 3.5 Transcribe ### Speech to Text ## Gemini 3.5 Transcribe API Documentation Google's Gemini 3.5 Transcribe converts pre-recorded speech to text, with automatic language identification across 85+ locales, speaker diarization, word-level timestamps and custom-vocabulary biasing. Accepts WAV, MP3, AIFF, AAC, OGG, FLAC, M4A, Opus, WebM and MPEG, up to 1 hour per request. Asynchronous: submit returns a `request_id`; poll the status endpoint until the request is `COMPLETED`, then fetch the JSON transcript from the returned url. ``` POST https://gateway.pixazo.ai/gemini-3-5-transcribe/v1/speech-to-text ``` ## Authentication All requests require an API key passed via header. Header Type Required Description Ocp-Apim-Subscription-Key string Yes Your API subscription key ## Speech to Text - Gemini 3.5 Transcribe ## Request Code HTTP Python JavaScript cURL ``` POST https://gateway.pixazo.ai/gemini-3-5-transcribe/v1/speech-to-text Content-Type: application/json Ocp-Apim-Subscription-Key: YOUR_SUBSCRIPTION_KEY { "audio_url": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/doc-assets/audio/speech-17s.mp3" } ``` ``` import requests url = "https://gateway.pixazo.ai/gemini-3-5-transcribe/v1/speech-to-text" headers = { "Content-Type": "application/json", "Ocp-Apim-Subscription-Key": "YOUR_SUBSCRIPTION_KEY" } data = { "audio_url": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/doc-assets/audio/speech-17s.mp3" } resp = requests.post(url, json=data, headers=headers) print(resp.json()) ``` ``` const res = await fetch("https://gateway.pixazo.ai/gemini-3-5-transcribe/v1/speech-to-text", { method: "POST", headers: { "Content-Type": "application/json", "Ocp-Apim-Subscription-Key": "YOUR_SUBSCRIPTION_KEY" }, body: JSON.stringify({ "audio_url": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/doc-assets/audio/speech-17s.mp3" }) }); console.log(await res.json()); ``` ``` curl -X POST 'https://gateway.pixazo.ai/gemini-3-5-transcribe/v1/speech-to-text' \ -H 'Content-Type: application/json' \ -H 'Ocp-Apim-Subscription-Key: YOUR_SUBSCRIPTION_KEY' \ --data-raw '{"audio_url": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/doc-assets/audio/speech-17s.mp3"}' ``` ## Output ``` { "request_id": "gemini-3-5-transcribe_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "QUEUED", "polling_url": "https://gateway.pixazo.ai/v2/requests/status/gemini-3-5-transcribe_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" } ``` [Try Now](https://api.pixazo.ai/api-details#api=gemini-3-5-transcribe&operation=speech-to-text) ## Webhook (Optional) Instead of polling, you can receive a Webhook callback when the request reaches a terminal state. Provide a Webhook URL via header on the submit request. Header Required Description X-Webhook-URL To enable HTTPS URL to receive the Webhook callback. X-Webhook-Mode No `terminal` (default, one callback on COMPLETED/ERROR) or `sync` (per-poll callbacks). ### Example: enable Webhook ``` curl -X POST 'https://gateway.pixazo.ai/gemini-3-5-transcribe/v1/speech-to-text' \ -H 'Content-Type: application/json' \ -H 'Ocp-Apim-Subscription-Key: YOUR_SUBSCRIPTION_KEY' \ -H 'X-Webhook-URL: https://your-server.com/webhook' \ --data-raw '{"audio_url": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/doc-assets/audio/speech-17s.mp3"}' ``` ### Callback Payload (success) ``` { "request_id": "gemini-3-5-transcribe_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "COMPLETED", "model_id": "gemini-3-5-transcribe", "output": { "media_url": [ "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/v1/{request_id}/transcript.json" ], "media_type": "application/json" }, "duration": 19.17, "created_at": "2026-08-01T09:14:16.102Z", "completed_at": "2026-08-01T09:14:22.870Z" } ``` ### Failure callback shape ``` { "request_id": "gemini-3-5-transcribe_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "ERROR", "model_id": "gemini-3-5-transcribe", "error": "Description of the failure" } ``` #### Delivery semantics - **terminal** mode: one Webhook callback when the request is COMPLETED or ERROR. - **sync** mode: a Webhook callback on each status change. - Callbacks are idempotent on `request_id` — de-duplicate on it. - Respond `200` within a few seconds; the Webhook endpoint must be HTTPS. ## Request Parameters Parameter Required Type Default Allowed values / range Description `audio_url` Yes string — a publicly reachable http(s) url The recording to transcribe. We fetch it server-side, so it must be reachable from the internet — a signed url is fine, a private one is not. Accepts WAV, MP3, AIFF, AAC, OGG, FLAC, M4A, Opus, WebM and MPEG. `language_codes` No array — (auto-detected) BCP-47 codes, e.g. `["en-US"]` Leave this out and the model identifies the language itself across 85+ locales, including speakers switching language mid-recording. Set it to pin the transcript to a known language. `mode` No string `verbatim` `verbatim`, `smart` `verbatim` transcribes exactly what was said, keeping filler words, repetitions and false starts. `smart` cleans that up — removing disfluencies, applying self-corrections, and formatting lists, numbers, dates and paragraph breaks. `smart` cannot be combined with `diarization` or `timestamps`. `diarization` No boolean `false` `true`, `false` Label who is speaking, for up to 8 speakers. Each word in the transcript carries a `speaker` tag. Requires `mode` `verbatim`. `timestamps` No boolean `false` `true`, `false` Word-level start and end times, in seconds. Requires `mode` `verbatim`. `custom_vocabulary` No array — up to 1,000 terms Bias the transcript toward terms the model would otherwise misspell — product names, people, domain jargon. ### Limits Audio up to **1 hour** per request. Turning on `diarization` or `timestamps` lowers that ceiling to **30 minutes**. Billing is per minute of _input_ audio, rounded up to the next whole minute — so a 20-second clip and a 55-second clip both bill one minute. ## Example Request ``` { "audio_url": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/doc-assets/audio/speech-17s.mp3" } ``` ## Example Response ``` { "request_id": "gemini-3-5-transcribe_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "QUEUED", "polling_url": "https://gateway.pixazo.ai/v2/requests/status/gemini-3-5-transcribe_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" } ``` ## Request Headers Header Required Description Content-Type Yes `application/json` Ocp-Apim-Subscription-Key Yes Your API subscription key. X-Webhook-URL No Enable Webhook callbacks (see Webhook section). ## Response Handling Status Code Meaning 202 Accepted — request queued; returns `request_id` and `polling_url`. 400 Bad request — a missing or out-of-range parameter. The message names the field. 401 Unauthorized — missing or invalid subscription key. 402 Insufficient balance. 429 Too many requests. 500 Internal server error. ## Retrieving Results Poll the status endpoint with the `request_id` from the submit response until `status` is `COMPLETED` (or `ERROR`), then download `output.media_url`. ``` curl 'https://gateway.pixazo.ai/v2/requests/status/gemini-3-5-transcribe_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx' \ -H 'Ocp-Apim-Subscription-Key: YOUR_SUBSCRIPTION_KEY' ``` ### Completed response ``` { "request_id": "gemini-3-5-transcribe_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "COMPLETED", "model_id": "gemini-3-5-transcribe", "output": { "media_url": [ "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/v1/{request_id}/transcript.json" ], "media_type": "application/json" }, "duration": 19.17, "created_at": "2026-08-01T09:14:16.102Z", "completed_at": "2026-08-01T09:14:22.870Z" } ``` ## Response Fields Field Type Description request\_id string Unique request identifier. status string QUEUED, PROCESSING, COMPLETED or ERROR. model\_id string The model that handled the request. output.media\_url array URL of the JSON transcript file. Fetch it to read `text`, and `segments` when you asked for timestamps or diarization. output.media\_type string Always `application/json` — the result is a transcript document, not audio. created\_at string Request creation timestamp. completed\_at string Completion timestamp. error string Error message when `status` is ERROR. ## Status Values & Flow `QUEUED` → `PROCESSING` → `COMPLETED` (success) or `ERROR` (failure). ### Pricing Billed at **$0.006 per minute of generated audio**, rounded up to the next whole minute. You are charged for the audio produced, not the text you submit. Audio produced Billed minutes Cost A 10-second clip 1 $0.006 A 45-second clip 1 $0.006 A 3-minute narration 3 $0.018 A 10-minute narration 10 $0.06 Failed requests are not billed. ## Gemini 3.1 Flash TTS ### Text to Speech ## Gemini 3.1 Flash TTS API Documentation Google's Gemini 3.1 Flash TTS turns text into speech, with 30 prebuilt voices, natural-language control over delivery, optional two-speaker dialogue and 90+ languages detected automatically. Asynchronous: submit returns a `request_id`; poll the status endpoint until the request is `COMPLETED`, then download the WAV from the returned url. ``` POST https://gateway.pixazo.ai/gemini-3-1-flash-tts/v1/text-to-speech ``` ## Authentication All requests require an API key passed via header. Header Type Required Description Ocp-Apim-Subscription-Key string Yes Your API subscription key ## Text to Speech - Gemini 3.1 Flash TTS ## Request Code HTTP Python JavaScript cURL ``` POST https://gateway.pixazo.ai/gemini-3-1-flash-tts/v1/text-to-speech Content-Type: application/json Ocp-Apim-Subscription-Key: YOUR_SUBSCRIPTION_KEY { "text": "Say warmly: Welcome back — your report is ready.", "voice": "Kore" } ``` ``` import requests url = "https://gateway.pixazo.ai/gemini-3-1-flash-tts/v1/text-to-speech" headers = { "Content-Type": "application/json", "Ocp-Apim-Subscription-Key": "YOUR_SUBSCRIPTION_KEY" } data = { "text": "Say warmly: Welcome back — your report is ready.", "voice": "Kore" } resp = requests.post(url, json=data, headers=headers) print(resp.json()) ``` ``` const res = await fetch("https://gateway.pixazo.ai/gemini-3-1-flash-tts/v1/text-to-speech", { method: "POST", headers: { "Content-Type": "application/json", "Ocp-Apim-Subscription-Key": "YOUR_SUBSCRIPTION_KEY" }, body: JSON.stringify({ "text": "Say warmly: Welcome back — your report is ready.", "voice": "Kore" }) }); console.log(await res.json()); ``` ``` curl -X POST 'https://gateway.pixazo.ai/gemini-3-1-flash-tts/v1/text-to-speech' \ -H 'Content-Type: application/json' \ -H 'Ocp-Apim-Subscription-Key: YOUR_SUBSCRIPTION_KEY' \ --data-raw '{ "text": "Say warmly: Welcome back — your report is ready.", "voice": "Kore" }' ``` ## Output ``` { "request_id": "gemini-3-1-flash-tts_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "QUEUED", "polling_url": "https://gateway.pixazo.ai/v2/requests/status/gemini-3-1-flash-tts_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" } ``` [Try Now](https://api.pixazo.ai/api-details#api=gemini-3-1-flash-tts&operation=text-to-speech) ## Webhook (Optional) Instead of polling, you can receive a Webhook callback when the request reaches a terminal state. Provide a Webhook URL via header on the submit request. Header Required Description X-Webhook-URL To enable HTTPS URL to receive the Webhook callback. X-Webhook-Mode No `terminal` (default, one callback on COMPLETED/ERROR) or `sync` (per-poll callbacks). ### Example: enable Webhook ``` curl -X POST 'https://gateway.pixazo.ai/gemini-3-1-flash-tts/v1/text-to-speech' \ -H 'Content-Type: application/json' \ -H 'Ocp-Apim-Subscription-Key: YOUR_SUBSCRIPTION_KEY' \ -H 'X-Webhook-URL: https://your-server.com/webhook' \ --data-raw '{ "text": "Say warmly: Welcome back — your report is ready.", "voice": "Kore" }' ``` ### Callback Payload (success) ``` { "request_id": "gemini-3-1-flash-tts_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "COMPLETED", "model_id": "gemini-3-1-flash-tts", "output": { "media_url": [ "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/v1/{request_id}/transcript.json" ], "media_type": "application/json" }, "duration": 19.17, "created_at": "2026-08-01T09:14:16.102Z", "completed_at": "2026-08-01T09:14:22.870Z" } ``` ### Failure callback shape ``` { "request_id": "gemini-3-1-flash-tts_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "ERROR", "model_id": "gemini-3-1-flash-tts", "error": "Description of the failure" } ``` #### Delivery semantics - **terminal** mode: one Webhook callback when the request is COMPLETED or ERROR. - **sync** mode: a Webhook callback on each status change. - Callbacks are idempotent on `request_id` — de-duplicate on it. - Respond `200` within a few seconds; the Webhook endpoint must be HTTPS. ## Request Parameters Parameter Required Type Default Allowed values / range Description `text` Yes string — up to ~8,000 tokens What to say. This is also where you direct _how_ it is said — the model follows natural-language direction, so "Say warmly and slowly: ..." works, as do inline tags like `[whispers]` and `[laughs]`. `voice` No string `Kore` Zephyr, Puck, Charon, Kore, Fenrir, Leda, Orus, Aoede, Callirrhoe, Autonoe, Enceladus, Iapetus, Umbriel, Algieba, Despina, Erinome, Algenib, Rasalgethi, Laomedeia, Achernar, Alnilam, Schedar, Gacrux, Pulcherrima, Achird, Zubenelgenubi, Vindemiatrix, Sadachbia, Sadaltager, Sulafat Which of the 30 prebuilt voices to speak in. Ignored when `speakers` is given. `speakers` No array — at most 2 entries Two-speaker dialogue. Each entry is `{"speaker": "Joe", "voice": "Kore"}`, where `speaker` matches a name used in your `text`. Supplying this replaces `voice`. ### Limits A session has a 32k-token context. Speech quality can drift on outputs longer than a few minutes, so split long scripts into separate requests. Language is detected from the text automatically across 90+ languages. Billing is per minute of _generated_ audio, rounded up to the next whole minute. ## Example Request ``` { "text": "Say warmly: Welcome back — your report is ready.", "voice": "Kore" } ``` ## Example Response ``` { "request_id": "gemini-3-1-flash-tts_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "QUEUED", "polling_url": "https://gateway.pixazo.ai/v2/requests/status/gemini-3-1-flash-tts_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" } ``` ## Request Headers Header Required Description Content-Type Yes `application/json` Ocp-Apim-Subscription-Key Yes Your API subscription key. X-Webhook-URL No Enable Webhook callbacks (see Webhook section). ## Response Handling Status Code Meaning 202 Accepted — request queued; returns `request_id` and `polling_url`. 400 Bad request — a missing or out-of-range parameter. The message names the field. 401 Unauthorized — missing or invalid subscription key. 402 Insufficient balance. 429 Too many requests. 500 Internal server error. ## Retrieving Results Poll the status endpoint with the `request_id` from the submit response until `status` is `COMPLETED` (or `ERROR`), then download `output.media_url`. ``` curl 'https://gateway.pixazo.ai/v2/requests/status/gemini-3-1-flash-tts_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx' \ -H 'Ocp-Apim-Subscription-Key: YOUR_SUBSCRIPTION_KEY' ``` ### Completed response ``` { "request_id": "gemini-3-1-flash-tts_01a0xxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "status": "COMPLETED", "model_id": "gemini-3-1-flash-tts", "output": { "media_url": [ "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/v1/{request_id}/transcript.json" ], "media_type": "application/json" }, "duration": 19.17, "created_at": "2026-08-01T09:14:16.102Z", "completed_at": "2026-08-01T09:14:22.870Z" } ``` ## Response Fields Field Type Description request\_id string Unique request identifier. status string QUEUED, PROCESSING, COMPLETED or ERROR. model\_id string The model that handled the request. output.media\_url array URL of the generated WAV file (PCM, 24 kHz, mono). output.media\_type string Always `audio/wav`. created\_at string Request creation timestamp. completed\_at string Completion timestamp. error string Error message when `status` is ERROR. ## Status Values & Flow `QUEUED` → `PROCESSING` → `COMPLETED` (success) or `ERROR` (failure). ### Pricing Billed at **$0.006 per minute of generated audio**, rounded up to the next whole minute. You are charged for the audio produced, not the text you submit. Audio produced Billed minutes Cost A 10-second clip 1 $0.006 A 45-second clip 1 $0.006 A 3-minute narration 3 $0.018 A 10-minute narration 10 $0.06 Failed requests are not billed.