Gemini 2.5 Pro TTS API

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

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.

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

All Gemini models

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

• Gemini 3.8 Flash TTS APIExpressive speech that acts out cues like [laughing]From 0.05 credits per second
• Gemini 3.8 Flash-Lite TTS APIFast, lightweight speech in 30 voicesFrom 0.03 credits per second
• Gemini 2.5 Pro TTS APIDirectable voices for narration and two-person dialogueFrom 0.07 credits per second

Other audio APIs

• MiniMax Speech 2.8 HD APIHigh-fidelity speech in 400+ voices with emotion controlFrom 18 credits per 1,000 characters
• Grok TTS API71 voices across 20 languages with speech tagsFrom 3 credits per 1,000 characters
• Seed Speech 2.0 API41 voices with tone set in plain languageFrom 11 credits per 1,000 characters
• MiniMax Speech 2.8 Turbo APIFast speech in 400+ voices with emotion controlFrom 11 credits per 1,000 characters
• Qwen3 TTS APIOpen-source speech with tone and pace set in plain wordsFrom 11 credits per 1,000 characters
• Chatterbox APIEnglish speech that can match a short voice sampleFrom 6 credits per run

More about Gemini 2.5 Pro TTS

Try it

Gemini 2.5 Pro TTS AI Voice Generator onlineCreate audio with Gemini 2.5 Pro TTS in PopNow

Docs

Gemini 2.5 Pro TTS model ID and input schema in the API docsPopNow API quickstart: your first request in five minutesWebhooks: get Gemini 2.5 Pro TTS results without polling