Gemini 3.8 Flash Lite TTS Text to Speech API

google/gemini-3.8-flash-lite/text-to-speech

Gemini 3.8 Flash Lite TTS Text to Speech turns scripts and two-speaker dialogues into WAV speech across 101 languages at 6 credits per 1,000 characters. It keeps the 30 preset voices, style instructions and dialogue format of Gemini 3.8 Flash TTS, so high-volume read-aloud work stays simple to scale.

Input

Request form

Text

Voice

Style Instructions

207 billable characters

Enable Safety Checker

Output

Explore more speech models

Gemini 3.8 Flash TTS Text to Speech Gemini 3.1 Flash TTS Text to Speech ElevenLabs V4 Turbo Text to Speech

Examples

Mandarin course narration

Mandarin course narration — A short Mandarin e-learning narration with a friendly teaching style.

Gemini 3.8 Flash Lite TTS Text to Speech API

Generate speech with the API

Submit a script, keep the returned task_id, and retrieve the completed audio through the task status endpoint.

Authenticate your request

Send your Vidgo API key in the Authorization header using Bearer authentication.

Endpoint: POSThttps://api.vidgo.ai/api/generate/submit
Authentication: Authorization: Bearer YOUR_API_KEY

Submit the script or dialogue

Send model and input as JSON. The example below uses the first audio sample on this page.

Request example

REQUEST_BODY=$(cat <<'JSON'
{
  "model": "google/gemini-3.8-flash-lite/text-to-speech",
  "input": {
    "text": "City crews will begin repaving Harbor Street on Monday. The work is expected to last two weeks, and buses on routes 4 and 9 will use Elm Avenue during that time.",
    "voice": "Kore",
    "style_instructions": "Clear, neutral news delivery at a steady pace.",
    "enable_safety_checker": true
  }
}
JSON
)

RESPONSE=$(curl --silent --show-error --fail-with-body \
  --request POST \
  --url "https://api.vidgo.ai/api/generate/submit" \
  --header "Authorization: Bearer $VIDGO_API_KEY" \
  --header "Content-Type: application/json" \
  --data "$REQUEST_BODY")

CODE=$(printf '%s' "$RESPONSE" | jq -r '.code // empty')
if [ "$CODE" != "0" ] && [ "$CODE" != "200" ]; then
  printf 'API error: %s
' "$RESPONSE" >&2
  exit 1
fi
printf '%s
' "$RESPONSE"

Follow the task

Query the returned task_id until status is finished or failed.

Status endpoint

GET https://api.vidgo.ai/api/generate/status/{task_id}

Keep the task_id from submission. Check its status and read the generated files when it finishes.

not_startedrunningfinishedfailed

Submission response

{
  "code": 200,
  "data": {
    "task_id": "IK592ONF5J9OUQMH",
    "status": "not_started",
    "created_time": "2026-11-05T07:14:06"
  }
}

Completed response

{
  "code": 200,
  "data": {
    "task_id": "IK592ONF5J9OUQMH",
    "status": "finished",
    "files": [
      {
        "file_url": "https://cdn.vidgo.ai/apis/models/google/gemini-3.8-flash-lite/text-to-speech/v2/01/speech-01.wav",
        "file_type": "audio",
        "file_name": "speech-01.wav"
      }
    ],
    "created_time": "2026-11-05T07:14:06",
    "error_message": null,
    "progress": 100
  }
}

Read the audio files

Use the audio file_url to play or download the WAV file.

Read the audio files

set -euo pipefail
: "${VIDGO_API_KEY:?Set VIDGO_API_KEY in your environment}"

REQUEST_BODY=$(cat <<'JSON'
{
  "model": "google/gemini-3.8-flash-lite/text-to-speech",
  "input": {
    "text": "City crews will begin repaving Harbor Street on Monday. The work is expected to last two weeks, and buses on routes 4 and 9 will use Elm Avenue during that time.",
    "voice": "Kore",
    "style_instructions": "Clear, neutral news delivery at a steady pace.",
    "enable_safety_checker": true
  }
}
JSON
)

SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  --request POST \
  --url "https://api.vidgo.ai/api/generate/submit" \
  --header "Authorization: Bearer $VIDGO_API_KEY" \
  --header "Content-Type: application/json" \
  --data "$REQUEST_BODY")

TASK_ID=$(printf '%s' "$SUBMIT_RESPONSE" | jq -r '.data.task_id // .task_id // empty')
BUSINESS_CODE=$(printf '%s' "$SUBMIT_RESPONSE" | jq -r '.code // empty')
if [ "$BUSINESS_CODE" != "0" ] && [ "$BUSINESS_CODE" != "200" ]; then
  printf 'Submit failed:
%s
' "$SUBMIT_RESPONSE" >&2
  exit 1
fi
if [ -z "$TASK_ID" ]; then
  printf 'Submit response did not include task_id:
%s
' "$SUBMIT_RESPONSE" >&2
  exit 1
fi

START_TIME=$(date +%s)
POLL_DELAY=2
while true; do
  if [ $(( $(date +%s) - START_TIME )) -ge 600 ]; then
    printf 'Timed out after 600 seconds
' >&2
    exit 1
  fi
  STATUS_RESPONSE=$(curl --silent --show-error --fail-with-body \
    --url "https://api.vidgo.ai/api/generate/status/$TASK_ID" \
    --header "Authorization: Bearer $VIDGO_API_KEY")
  STATUS=$(printf '%s' "$STATUS_RESPONSE" | jq -r '.data.status // .status // empty')
  BUSINESS_CODE=$(printf '%s' "$STATUS_RESPONSE" | jq -r '.code // empty')
  if [ "$BUSINESS_CODE" != "0" ] && [ "$BUSINESS_CODE" != "200" ]; then
    printf 'Status request failed:
%s
' "$STATUS_RESPONSE" >&2
    exit 1
  fi

  case "$STATUS" in
    finished)
      printf '%s' "$STATUS_RESPONSE" | jq -r '(.data.files // .files // [])[]?.file_url'
      break
      ;;
    failed)
      printf '%s' "$STATUS_RESPONSE" | jq -r '.data.error_message // .error_message // "Generation failed"' >&2
      exit 1
      ;;
    not_started|running)
      sleep "$POLL_DELAY"
      if [ "$POLL_DELAY" -lt 10 ]; then POLL_DELAY=$((POLL_DELAY + 1)); fi
      ;;
    *)
      printf 'Unexpected task status: %s
' "$STATUS" >&2
      exit 1
      ;;
  esac
done

Request parameters

Place speech controls inside input; keep model and callback_url at the top level.

Field	Type	Required	Default	Description
model	string	Yes	—	Use google/gemini-3.8-flash-lite/text-to-speech to select this speech model.
input	object	Yes	—	Use text and voice for one speaker, or speakers and turns for a dialogue, plus the optional fields below.
input.text	string	Single speaker	—	Single speaker: the script to speak. Write the words as they should be heard; place acting directions in Style Instructions.
input.voice	string	Optional	Kore	Single speaker: one of the 30 preset voices. Default Kore. Voices: Achernar, Achird, Algenib, Algieba, Alnilam, Aoede, Autonoe, Callirrhoe, Charon, Despina, Enceladus, Erinome, Fenrir, Gacrux, Iapetus, Kore, Laomedeia, Leda, Orus, Pulcherrima, Puck, Rasalgethi, Sadachbia, Sadaltager, Schedar, Sulafat, Umbriel, Vindemiatrix, Zephyr, Zubenelgenubi.
input.speakers	array	Dialogue	—	Dialogue: exactly two speakers, each with a unique speaker_id and one of the 30 preset voices.
input.speakers[].speaker_id	string	Per item	—	A unique, non-empty name for the speaker, such as Host.
input.speakers[].voice	string	Per item	—	The speaker's preset voice. Voices: Achernar, Achird, Algenib, Algieba, Alnilam, Aoede, Autonoe, Callirrhoe, Charon, Despina, Enceladus, Erinome, Fenrir, Gacrux, Iapetus, Kore, Laomedeia, Leda, Orus, Pulcherrima, Puck, Rasalgethi, Sadachbia, Sadaltager, Schedar, Sulafat, Umbriel, Vindemiatrix, Zephyr, Zubenelgenubi.
input.turns	array	Dialogue	—	Dialogue: the lines in order. Each turn names a speaker_id from Speakers, its text, and optional style_instructions for that line.
input.turns[].speaker_id	string	Per item	—	The speaker_id of the speaker who says this line.
input.turns[].text	string	Per item	—	The words of this line, not blank.
input.turns[].style_instructions	string	Optional	—	Optional direction for this line only.
input.style_instructions	string	Optional	—	Optional delivery direction for the whole request, such as tone, pace or setting. Its characters count toward billing.
input.enable_safety_checker	boolean	Optional	true	Runs the upstream safety checker on the request. Default true.
callback_url	string	No	—	Optional HTTP or HTTPS URL for task notifications. Include it at the top level of the request.

Response fields

Submission identifies the task. Status responses report progress toward the completed audio.

Field	Type	Description
code	integer	Response code. A successful response uses 200 or 0.
data.task_id	string	Task identifier used to query status.
data.status	string	Task state: not_started, running, finished, or failed.
data.created_time	string	Task creation time returned by the service.
data.files	array	Generated files; the audio entry holds the WAV speech.
data.files[].file_url	string	URL used to play or download a generated file.
data.files[].file_type	string	audio for the generated speech.
data.files[].file_name	string	File name, when returned.
data.error_message	string \| null	Error details when a task fails.

Task lifecycle

Use the task state to decide when to check again or read the result.

not_started
The task has been accepted and is waiting to start.
running
Speech generation is in progress. Continue checking the same task.
finished
Generation is complete. Read files for the WAV audio.
failed
Generation failed. Read error_message before deciding whether to submit a new request.

Handle results and interruptions

Keep the current task identifierIf a status request is interrupted, query the same task_id again to recover its latest state.
Match each file to its purposeRead the audio entry in files and use its file_url and file_name for download.
Inspect a failed taskWhen status is failed, read error_message and review the script and settings before submitting another generation.

Speech specifications

Item	Value	Description
Task	Text to Speech	Single-speaker speech or a two-speaker dialogue.
Voices	30 presets	Kore by default; one voice per speaker in dialogue.
Speakers	1 or 2	Dialogue uses exactly two speakers and one or more turns.
Languages	101	Detected automatically from the transcript.
Output	WAV	One audio file per task.
Price	$0.030 / 1K characters	6 credits per 1,000 billable characters.

View the Gemini 3.8 Flash Lite TTS Text to Speech API docs

Gemini 3.8 Flash Lite TTS Text to Speech

Gemini 3.8 Flash Lite TTS Text to Speech is a Google model from September 2026 built for high throughput and cost efficiency, and Google recommends it for high-volume production speech. It detects the language of each script across 101 languages and uses the same 30 preset voices, style instructions and two-speaker dialogue format as Gemini 3.8 Flash TTS. At 6 credits per 1,000 characters it fits read-aloud features, course narration and app prompts.

Why choose Gemini 3.8 Flash Lite TTS?

Built for volumeAt 6 credits ($0.03) per 1,000 characters, one million characters cost 6,000 credits.
Same request as Gemini 3.8 Flash TTSVoices, style instructions and the dialogue format are identical, so you can move a script between the two by changing model.
101 languages detected automaticallyWrite each script in its language and the model reads it without a language code.
Two-speaker answers and explainersUse speakers and turns for question-and-answer audio, short FAQs or simple interviews.

Speech parameters

Parameter	Requirement	What it controls
text	Single speaker	Single speaker: the script to speak. Write the words as they should be heard; place acting directions in Style Instructions.
voice	Optional	Single speaker: one of the 30 preset voices. Default Kore. Default`KoreAchernarAchirdAlgenibAlgiebaAlnilamAoedeAutonoeCallirrhoeCharonDespinaEnceladusErinomeFenrirGacruxIapetusLaomedeiaLedaOrusPulcherrimaPuckRasalgethiSadachbiaSadaltagerSchedarSulafatUmbrielVindemiatrixZephyrZubenelgenubi`
speakers	Dialogue	Dialogue: exactly two speakers, each with a unique speaker_id and one of the 30 preset voices.
speakers[].speaker_id	Per item	A unique, non-empty name for the speaker, such as Host.
speakers[].voice	Per item	The speaker's preset voice. `AchernarAchirdAlgenibAlgiebaAlnilamAoedeAutonoeCallirrhoeCharonDespinaEnceladusErinomeFenrirGacruxIapetusKoreLaomedeiaLedaOrusPulcherrimaPuckRasalgethiSadachbiaSadaltagerSchedarSulafatUmbrielVindemiatrixZephyrZubenelgenubi`
turns	Dialogue	Dialogue: the lines in order. Each turn names a speaker_id from Speakers, its text, and optional style_instructions for that line.
turns[].speaker_id	Per item	The speaker_id of the speaker who says this line.
turns[].text	Per item	The words of this line, not blank.
turns[].style_instructions	Optional	Optional direction for this line only.
style_instructions	Optional	Optional delivery direction for the whole request, such as tone, pace or setting. Its characters count toward billing.
enable_safety_checker	Optional	Runs the upstream safety checker on the request. Default true. Default`truefalse`

Create speech in four steps

Choose the request formSelect Single speaker for one voice, or Dialogue for two speakers and their turns.
Write text or turnsEnter the transcript as it should be heard. For dialogue, assign each turn to a speaker.
Add style instructionsDescribe tone, pace or setting for the whole request, and add a short direction to individual turns if needed.
Run and download WAVCheck the cost on the Run button, select Run and download the WAV file when the task finishes.

Character-based pricing

Gemini 3.8 Flash Lite TTS Text to Speech costs $0.030, or 6 credits, per 1,000 billable characters. Billable characters are Text plus Style Instructions, and in dialogue every turn's text and style instructions; speaker IDs are not counted.

Text length	Cost	Calculation
1,000 characters	$0.030 · 6 credits	1000 × 6 / 1000 = 6 credits
100,000 characters	$3.00 · 600 credits	100000 × 6 / 1000 = 600 credits
1,000,000 characters	$30.00 · 6,000 credits	1000000 × 6 / 1000 = 6,000 credits

Where it fits

Article and document read-aloudVoice news items, help articles and notifications at a low cost per character.
Bulk course narrationProduce many short lessons across 101 languages with a consistent preset voice.
Two-voice FAQsTurn a customer question and a support answer into a short dialogue clip.
Draft voiceoversCreate many variants of an ad or explainer script before choosing the final read.

Pro tips

Keep acting directions in Style Instructions; Google notes that Gemini 3.8 TTS reads the transcript literally.
Give dialogue speakers short, distinct IDs such as Host and Guest, and match each turn to one of them.
Use a per-turn style instruction only where a line needs a different emotion from the global direction.
Pick contrasting voices for two speakers, for example Kore with Puck, so listeners can follow who is talking.
Move a key script to Gemini 3.8 Flash TTS by changing only model when it needs more acting nuance.

Before you publish

Audio is returned as a WAV file. Convert it in your audio tool if your player needs MP3 or Opus.
Google sets an input limit of 8,192 tokens for this model; split very long scripts into several requests.

Explore more speech models

Gemini 3.8 Flash TTS Text to Speech preview

Gemini 3.8 Flash TTS Text to SpeechGoogle's flagship 3.8 speech tier for richer acting nuance.

Gemini 3.1 Flash TTS Text to Speech preview

Gemini 3.1 Flash TTS Text to SpeechThe previous Gemini speech model with output format and language options.

ElevenLabs V4 Turbo Text to Speech preview

ElevenLabs V4 Turbo Text to SpeechLower-cost ElevenLabs speech with audio tags and 19 formats.

Gemini 3.8 Flash Lite TTS Text to Speech API frequently asked questions

What is the Gemini 3.8 Flash Lite TTS Text to Speech API?

Gemini 3.8 Flash Lite TTS Text to Speech is a Google model for fast, cost-efficient speech generation. It produces single-voice speech or two-speaker dialogue in 101 languages with the same 30 preset voices and style instructions as Gemini 3.8 Flash TTS. Google designed the Flash Lite tier for high-throughput production while keeping the transcript read exactly as written. You can call it programmatically or try it from the playground above.

How do I create a two-speaker dialogue with Gemini 3.8 Flash Lite TTS?

Choose Dialogue and send exactly two speakers, each with a speaker_id and a preset voice, plus a turns list. Every turn names one speaker_id, its text and an optional style_instructions. Top-level text and voice are left out in this form.

Where should acting directions go in Gemini 3.8 Flash Lite TTS?

Put them in style_instructions, either for the whole request or for a single turn. Google notes that Gemini 3.8 TTS reads the transcript literally, so directions written inside the text may be spoken aloud.

Which voices does Gemini 3.8 Flash Lite TTS offer?

There are 30 presets: Achernar, Achird, Algenib, Algieba, Alnilam, Aoede, Autonoe, Callirrhoe, Charon, Despina, Enceladus, Erinome, Fenrir, Gacrux, Iapetus, Kore, Laomedeia, Leda, Orus, Pulcherrima, Puck, Rasalgethi, Sadachbia, Sadaltager, Schedar, Sulafat, Umbriel, Vindemiatrix, Zephyr, Zubenelgenubi. Kore is the default for a single speaker.

How does Gemini 3.8 Flash Lite TTS handle languages?

Gemini 3.8 Flash Lite TTS detects the language from the transcript across 101 languages. Write each script in its target language; there is no separate language setting.

How does Gemini 3.8 Flash Lite TTS compare with Gemini 3.8 Flash TTS?

Both accept the same fields, 30 voices and two-speaker dialogue. Flash Lite covers 101 languages at 6 credits ($0.03) per 1,000 characters, while Gemini 3.8 Flash TTS covers 130 languages at 9 credits and is Google's tier for richer acting nuance. Test your dialogue scripts on both before a large run.

What audio format does Gemini 3.8 Flash Lite TTS return?

Each finished task returns a WAV file in files. Convert it to MP3 or Opus in your audio tool if your player or platform needs a compressed format.

How are Gemini 3.8 Flash Lite TTS characters counted for billing?

Billing counts Text, Style Instructions, and in dialogue every turn's text and style instructions, at 6 credits ($0.030) per 1,000 characters. Speaker IDs are not counted.