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by Google

Directable voices for narration and two-person dialogue

google/gemini-2.5-pro-tts/text-to-speechFrom 0.07 creditsper second · $0.0007
  • 30 voices
  • Text to Speech

About Gemini 2.5 Pro TTS

Google's Gemini 2.5 Pro text-to-speech model: send a script, pick one of 30 voices and get back a WAV file read in that voice.

Call it with the model name google/gemini-2.5-pro-tts/text-to-speech on POST /jobs/createTask, from 0.07 credits per second ($0.0007). New accounts get 30 free credits to try it in the Playground first.

Introduction

What it returns

One WAV file per task: 24 kHz, 16-bit, mono PCM. There are no word timings or subtitles in the result.

Choosing a voice

voice_id takes one of 30 prebuilt voices and defaults to Kore. The voice does not change with the language of the script.

Directing the delivery

  • style sets an overall manner: whisper, empathetic, vocal_smile, newscaster, promo_hype or deadpan. Leave it out and the voice reads in its own default manner.
  • accent picks an English accent and defaults to neutral.
  • pace sets the rhythm: natural, rapid_fire, the_drift or staccato.
  • instructions takes free text about how to read: pace, mood, distance from the microphone, who is being addressed. scene says where and to whom the words are spoken. Neither is spoken.
  • temperature (0–2) sets how much the delivery varies between takes.
  • Inside text, cues in square brackets such as [sighs] or [whispering] are acted out rather than read aloud.

Two voices in one clip

For a conversation, send dialogue instead of text, plus speakers with the cast: one or two entries, each with a name, a voice_id and optionally accent, style, pace and profile, a short description of who is speaking that is not read aloud. Each dialogue line is {speaker, text}, where speaker is one of those names; lines are performed in order, up to 20 lines of 250 characters each. Settings a speaker leaves out fall back to the top-level accent, style and pace.

Length and timing

text accepts up to 5,000 characters. A 270-character paragraph came back as 23–29 seconds of audio in our tests, depending on voice and style. The model stops at 16,384 audio tokens, about 655 seconds. Most tasks finish in under a minute.

Request parameters

ParameterRequiredDescription
paceNoRhythm of the reading. Omit it to keep the voice's own rhythm. natural · rapid_fire · the_drift · staccato
textNoThe words to be spoken, exactly as written. Cues in square brackets such as [sighs] are performed rather than read aloud.
sceneNoWhere and to whom the words are spoken. Shapes the delivery and is not spoken.
styleNoA preset look or genre. whisper · empathetic · vocal_smile · newscaster · promo_hype · deadpan
accentNoEnglish accent used for the reading. neutral · american_general · american_valley · american_south · british_rp · british_brixton · transatlantic · australian · Default: neutral
dialogueNoA scripted conversation, used instead of text: each line names a speaker from speakers.
speakersNoThe cast for dialogue: one or two voices, each with a name the lines refer to.
voice_idNoPick from the available voices. Achernar · Achird · Algenib · Algieba · Alnilam · Aoede · Autonoe · Callirrhoe · Charon · Despina · Enceladus · Erinome · Fenrir · Gacrux · Iapetus · Kore · Laomedeia · Leda · Orus · Puck · Pulcherrima · Rasalgethi · Sadachbia · Sadaltager · Schedar · Sulafat · Umbriel · Vindemiatrix · Zephyr · Zubenelgenubi · Default: Kore
temperatureNoVariation between takes; higher is less predictable. ≥ 0 · ≤ 2
instructionsNoHow to read the text: pace, mood, distance from the microphone, who is listening. Shapes the delivery and is not spoken.

Pricing

Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.

OptionCredits per second≈ USD
Standard0.07$0.0007

For an exact number before you run, send the same body to POST /jobs/quote.

API quick start

Call the Gemini 2.5 Pro TTS API in three steps

  1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
  2. Send the request. POST /jobs/createTask with model google/gemini-2.5-pro-tts/text-to-speech and an input object that follows the parameter table. The response returns a task ID straight away.
  3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.
# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "google/gemini-2.5-pro-tts/text-to-speech",
  "input": {
    "text": "Welcome back. Your files finished rendering a minute ago and are ready to download.",
    "voice_id": "Kore",
    "accent": "neutral"
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

Gemini 2.5 Pro TTS API questions

How much does the Gemini 2.5 Pro TTS API cost?

Gemini 2.5 Pro TTS costs 0.07 credits ($0.0007) per second. Credits are the same as on the website (1 credit = $0.01), new accounts get 30 free credits, and failed tasks are refunded.

What is the model name for Gemini 2.5 Pro TTS in the API?

Put google/gemini-2.5-pro-tts/text-to-speech for Text to Speech in the model field of POST /jobs/createTask.

How do I control how it sounds?

voice_id picks the voice, style sets an overall manner such as whisper or deadpan, accent picks an English accent, pace sets the rhythm, and instructions and scene take a sentence or two about delivery and setting — mood, who is being spoken to, where. Those notes shape the reading and are not read aloud; temperature sets how much takes vary.

Can it copy a real person's voice?

No. Only the 30 prebuilt voices are available; there is no cloning and no upload of a reference voice.

What are the limits of the Gemini 2.5 Pro TTS API?

Text length (characters): 5,000; Voices: 30. Requests outside these limits are rejected before anything is charged.

Can I try Gemini 2.5 Pro TTS without writing code?

Yes. The Playground runs Gemini 2.5 Pro TTS on your PopNow credits, needs no API key, and shows the matching code for every run.

All Gemini models

Gemini 3.8 Flash TTS is Google's newer model and acts out bracketed cues like [whispering] inside the script.

More about Gemini 2.5 Pro TTS