Gemini 2.5 Pro TTS API

High-quality TTS preview for podcasts, audiobooks, and customer support, with expressive multi-speaker voices across 23+ languages.

GoogleAudio GenerationProprietary Endpoint

About Gemini 2.5 Pro TTS

High-quality TTS preview for podcasts, audiobooks, and customer support, with expressive multi-speaker voices across 23+ languages.

Also known as Gemini TTS, Gemini-2.5-Pro-TTS

Gemini 2.5 Pro TTS specs

Model ID
gemini-2-5-pro-tts
Provider
Google
Category
Audio Generation
Input
text
Output
audio
Endpoints
POST /v1/audio/speech

Gemini 2.5 Pro TTS API pricing

Live pay-as-you-go rates from the EmpirioLabs catalog. You are billed only for what you use, with no monthly minimum.

Type
Spec
Rate
Input
per 1M prompt tokens
$3.00
Output
per 1M generated tokens
$60.00
Compare on the full pricing page

How to call the Gemini 2.5 Pro TTS API

Gemini 2.5 Pro TTS serves speech through POST /v1/audio/speech and returns playable audio. Send the text to speak as input with the model id gemini-2-5-pro-tts. Get an API key from the EmpirioLabs dashboard.

cURL
curl https://api.empiriolabs.ai/v1/audio/speech \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gemini-2-5-pro-tts",
    "input": "Welcome to EmpirioLabs. Your build just finished."
  }' \
  --output speech.mp3
Python
import requests

response = requests.post(
    "https://api.empiriolabs.ai/v1/audio/speech",
    headers={"Authorization": "Bearer YOUR_EMPIRIOLABS_API_KEY"},
    json={"model": "gemini-2-5-pro-tts", "input": "Welcome to EmpirioLabs."},
)
with open("speech.mp3", "wb") as f:
    f.write(response.content)
Full Gemini 2.5 Pro TTS API reference

Gemini 2.5 Pro TTS API parameters

Request parameters supported by the Gemini 2.5 Pro TTS API on EmpirioLabs. Defaults apply when a field is omitted.

ParameterTypeDefaultRange / valuesDescription
inputstring--Text to convert to speech. For multi-speaker mode, prefix lines with Speaker1: / Speaker2:.
modeenumsinglesingle, multisingle = one voice, multi = two-voice dialogue (uses voice + voice2 + speaker names).
languagestringen-US-BCP-47 language tag (en-US, es-ES, etc.) for pronunciation cues.
voiceenumCharonZephyr, Puck, Charon, Kore, Fenrir, Leda, Orus, Aoede, Callir...Primary voice name (e.g. Kore, Puck, Aoede). Leave blank for the default.
voice2enumKoreZephyr, Puck, Charon, Kore, Fenrir, Leda, Orus, Aoede, Callir...Second voice name for multi-speaker mode.
speaker1_namestringSpeaker1-Display name used in the input prefix for speaker 1 (default: Speaker1).
speaker2_namestringSpeaker2-Display name used in the input prefix for speaker 2 (default: Speaker2).
output_formatenumWAVWAV, MP3, OGG, ALAW, MULAWAudio file format (mp3, wav, opus, flac, etc.).
speednumber10.25 to 2Playback rate. 1.0 = natural; <1 slower, >1 faster.
volume_gainnumber0-96 to 16Output gain in dB. 0 = unchanged.
sample_rateenum240008000, 16000, 22050, 24000, 44100, 48000Output sample rate in Hz (8000, 16000, 24000, 44100, 48000).
style_promptstring--Natural-language style direction (e.g. "warm, conversational" or "newscaster, serious").

Good to know

Modes

  • Single speaker
  • Multi-speaker (max 2 voices) — text must be in SpeakerName: text format

Limits

  • Text + style prompt: 4,000 bytes each
  • Audio billing: ~32 tokens per second of generated audio (~10-15 chars/s)

Voices and languages

  • 30+ voice options across emotional/tonal characters
  • 24+ language locales supported

Output formats

  • MP3, WAV, OGG

Gemini 2.5 Pro TTS API: common questions

How much does the Gemini 2.5 Pro TTS API cost?

On EmpirioLabs, Gemini 2.5 Pro TTS is billed pay as you go: Input $3.00 per 1M prompt tokens; Output $60.00 per 1M generated tokens. The live rate card on this page always matches what the API charges.

Which endpoint does Gemini 2.5 Pro TTS use?

Gemini 2.5 Pro TTS is served through POST /v1/audio/speech on api.empiriolabs.ai with standard bearer-token authentication.

Can I try Gemini 2.5 Pro TTS in the browser before integrating?

Yes. The EmpirioLabs playground runs Gemini 2.5 Pro TTS in the browser with the same parameters the API exposes, so you can test prompts before writing code.

How do I get a Gemini 2.5 Pro TTS API key?

Create an EmpirioLabs account, then generate a key under API Keys in the dashboard. Billing is pay-as-you-go credits, so you only pay for the requests you make.

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