Elevenlabs Flash V2 API Documentation

Elevenlabs Flash V2 API Documentation

Playground

Try it on WaveSpeedAI!

ElevenLabs Flash V2 is a Text-to-Speech model that converts text into spoken audio using the ElevenLabs Flash V2 engine. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

Flash V2 turns written text into natural-sounding speech with crisp pronunciation, smooth pacing, and expressive tone—ideal for voiceovers, narration, tutorials, podcasts, and digital content. It supports a rich library of multi-lingual voices and low-latency generation for fast workflows. See the list here.


Key Features

  • Natural prosody with clear, humanlike articulation
  • Multilingual support with strong English numeral/date reading
  • Fine control via similarity and stability sliders
  • Speaker Boost to enhance English number and unit delivery

Pricing

Billed by the exact character count of the input text, prorated — no rounding up to 1,000.

  • Rate: $0.10 per 1,000 characters ($100 per 1M characters)
  • No minimum charge; a 100-character request costs $0.010
CharactersCost
100$0.010
500$0.05
1,000$0.10
10,000$1.00

How to Use

  1. Enter your script in the text field.
  2. Choose a voice_id (for example: Gigi, Callum, Alice; see the voice list for more).
  3. Optional controls • similarity: 0–1 (higher = closer to the base voice timbre) • stability: 0–1 (higher = more consistent delivery) • use_speaker_boost: improves English number and unit reading
  4. Run to synthesize and preview your audio.

Notes

  • For best prosody, keep sentences clear and use punctuation; split very long text into smaller chunks.
  • Ensure the voice_id is valid; use the official list linked above.
  • Speaker Boost is especially helpful for finance, time, and measurement scripts.

Authentication

For authentication details, please refer to the Authentication Guide.

API Endpoints

Submit Task & Query Result

set -euo pipefail

export WAVESPEED_API_KEY="your-api-key"

REQUEST_BODY=$(cat <<'JSON'
{
  "text": "A clear example input",
  "voice_id": "Alice",
  "similarity": 1,
  "stability": 0.5,
  "use_speaker_boost": true
}
JSON
)

# 1. Submit the prediction.
SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  -X POST "https://api.wavespeed.ai/api/v3/elevenlabs/flash-v2" \
  -H "Authorization: Bearer ${WAVESPEED_API_KEY}" \
  -H "Content-Type: application/json" \
  -d "${REQUEST_BODY}")

TASK=$(printf '%s' "${SUBMIT_RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
PREDICTION_ID=$(printf '%s' "${TASK}" | jq -r '.id // empty')
if [ -z "${PREDICTION_ID}" ]; then
  printf 'Submission response did not contain a prediction id
' >&2
  exit 1
fi
RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result"

# 2. Poll until the prediction finishes.
while true; do
  RESPONSE=$(curl --silent --show-error --fail-with-body \
    "${RESULT_URL}" \
    -H "Authorization: Bearer ${WAVESPEED_API_KEY}")
  RESULT=$(printf '%s' "${RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
  STATUS=$(printf '%s' "${RESULT}" | jq -r '.status // empty')

  case "${STATUS}" in
    completed) printf '%s\n' "${RESULT}" | jq '.outputs'; break ;;
    failed|cancelled|timeout|deleted) printf '%s\n' "${RESULT}" | jq . >&2; exit 1 ;;
    *) sleep 2 ;;
  esac
done

Parameters

Task Submission Parameters

Request Parameters

ParameterTypeRequiredDefaultRangeDescription
textstringYes--Text to convert to speech. Every character is 1 token. Maximum 10000 characters. Use <#x#> between words to control pause duration (0.01-99.99s).
voice_idstringYesAlice-The voice to use for speech generation
similaritynumberNo10 ~ 1High enhancement boosts overall voice clarity and target speaker similarity. Very high values can cause artifacts, so adjusting this setting to find the optimal value is encouraged.
stabilitynumberNo0.50 ~ 1Voice stability (0-1) Default value: 0.5
use_speaker_boostbooleanNotrue-This parameter supports English text normalization, which improves performance in number-reading scenarios.

Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
data.idstringUnique identifier for the prediction, Task Id
data.modelstringModel ID used for the prediction
data.outputsarrayOutput values, usually URL strings; some models return text strings or structured result objects (empty when status is not completed)
data.urlsobjectObject containing related API endpoints
data.statusstringTask status. completed is successful; failed, cancelled, timeout, and deleted are failure terminal statuses.
data.created_atstringISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”)
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds

Result Request Parameters

ParameterTypeRequiredDefaultDescription
idstringYes-Task ID

Result Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
dataobjectThe prediction data object containing all details
data.idstringUnique identifier for the prediction
data.modelstringModel ID used for the prediction
data.outputsarray<string | object>Array of generated outputs (empty when status is not completed). Items are usually URL strings, but may be text strings or structured result objects, depending on the model.
data.urlsobjectObject containing related API endpoints
data.statusstringStatus: completed is successful; failed, cancelled, timeout, and deleted are failure terminal statuses
data.created_atstringISO timestamp of when the request was created
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds
© 2026 WaveSpeedAI. All rights reserved.