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MODEL IDheygen:voice@1.0

HeyGen Voice 1.0

by October 22, 2026

HeyGen Voice 1.0 is HeyGen's text-to-speech model for spoken audio in 39 languages, with the language detected from the text when none is set. It speaks with a public voice or clones a new one from a single recording, and returns the cloned voice so later requests can reuse it. It suits voiceovers, narration for training and product videos, and localized content.

API Options

Platform-level options for task execution and delivery.

taskType stringrequiredvalue: audioInference: Identifier for the type of task being performed.

taskUUID stringrequiredUUID v4: UUID v4 identifier for tracking tasks and matching async responses. Must be unique per task.

outputType stringdefault: URL: Audio output type.
Allowed values3 values

outputFormat stringdefault: MP3

Specifies the file format of the generated output. The available values depend on the task type and the specific model's capabilities.

`MP3`: Compressed audio, smaller file size.
`WAV`: Uncompressed, high-quality audio.
`FLAC`: Lossless compression.
`OGG`: Open-source compressed audio format (Vorbis codec).

Allowed values4 values

audioSettings object

Audio encoding settings for controlling the bitrate, number of channels, and sample rate of the generated audio. Only applicable for lossy output formats (MP3 and OGG). When using lossless formats (WAV or FLAC), this parameter must not be provided.

The available sample rates and valid bitrate ranges depend on the output format. For OGG, bitrate limits also vary by the number of channels.

MP3 bitrate limits

Bitrate limits for MP3 are the same regardless of mono or stereo.

Sample Rate	Min Bitrate	Max Bitrate
8,000 Hz	8 kbps	64 kbps
11,025 Hz	8 kbps	64 kbps
12,000 Hz	8 kbps	64 kbps
16,000 Hz	8 kbps	160 kbps
22,050 Hz	8 kbps	160 kbps
24,000 Hz	8 kbps	160 kbps
32,000 Hz	32 kbps	320 kbps
44,100 Hz	32 kbps	320 kbps
48,000 Hz	32 kbps	320 kbps

OGG bitrate limits — Mono (1 channel)

Sample Rate	Min Bitrate	Max Bitrate
8,000 Hz	8 kbps	40 kbps
12,000 Hz	16 kbps	48 kbps
16,000 Hz	16 kbps	96 kbps
24,000 Hz	16 kbps	80 kbps
48,000 Hz	32 kbps	224 kbps

OGG bitrate limits — Stereo (2 channels)

Sample Rate	Min Bitrate	Max Bitrate
8,000 Hz	16 kbps	80 kbps
12,000 Hz	16 kbps	96 kbps
16,000 Hz	24 kbps	192 kbps
24,000 Hz	32 kbps	160 kbps
48,000 Hz	48 kbps	256 kbps

Lossless formats: When outputFormat is set to WAV or FLAC, the audioSettings parameter is not available since these formats produce uncompressed or lossless audio with no configurable encoding settings.

Properties3 properties

audioSettings » bitrate bitrate integermin: 8: Audio bitrate in kbps.

audioSettings » channels channels integerdefault: 2: Number of audio channels. 1 for mono, 2 for stereo.
Allowed values2 values

audioSettings » sampleRate sampleRate integer: Audio sample rate in Hz.

webhookURL stringuri

Webhook URL that receives JSON responses via HTTP POST when generation tasks complete. For batch requests with multiple results, each completed item triggers a separate webhook call as it becomes available.

Learn more1 resource

Webhooks
PLATFORM

deliveryMethod stringdefault: sync

Determines how the API delivers task results.

Allowed values2 values

: Returns complete results directly in the API response.
: Returns an immediate acknowledgment with the task UUID. Poll for results using getResponse.

Learn more1 resource

Task Polling
PLATFORM

uploadEndpoint stringuri

Specifies a URL where the generated content will be automatically uploaded using the HTTP PUT method. The raw binary data of the media file is sent directly as the request body. For secure uploads to cloud storage, use presigned URLs that include temporary authentication credentials.

Common use cases:

Cloud storage: Upload directly to S3 buckets, Google Cloud Storage, or Azure Blob Storage using presigned URLs.
CDN integration: Upload to content delivery networks for immediate distribution.

// S3 presigned URL for secure upload
https://your-bucket.s3.amazonaws.com/generated/content.mp4?X-Amz-Signature=abc123&X-Amz-Expires=3600

// Google Cloud Storage presigned URL
https://storage.googleapis.com/your-bucket/content.jpg?X-Goog-Signature=xyz789

// Custom storage endpoint
https://storage.example.com/uploads/generated-image.jpg

The content data will be sent as the request body to the specified URL when generation is complete.

ttl integermin: 60: Time-to-live (TTL) in seconds for generated content. Only applies when outputType is URL.

includeCost boolean: Include task cost in the response.

numberResults integermin: 1max: 4default: 1: Number of results to generate. Each result uses a different seed, producing variations of the same parameters.

routing object

Model router options. Only read when model is auto, and never sent to the model.

Properties3 properties

routing » preferences preferences object

Relative importance of each dimension when models are compared. Weights, not thresholds.

Properties3 properties

routing » preferences » quality quality integermin: 0max: 5: Importance of one dimension. 0 leaves it out of the decision.

routing » preferences » speed speed integermin: 0max: 5: Importance of one dimension. 0 leaves it out of the decision.

routing » preferences » cost cost integermin: 0max: 5: Importance of one dimension. 0 leaves it out of the decision.

routing » maxPrice maxPrice floatmin: 0: Upper bound on what this request may cost, in USD. A model whose cost cannot be bounded is not chosen.

routing » requirements requirements stringmax: 3000: Conditions the result has to meet, in plain words, such as a style or a feature. A model that cannot meet them is not chosen. Output size is set with width and height rather than described here.

Inputs

Input resources for the task (images, audio, etc). These must be nested inside the inputs object.

inputs » audio audio string1 limit: Audio input (UUID or URL). Recording to clone the voice from. Only the first 3 minutes are used.

Core Parameters

Primary parameters that define the task output.

model stringrequiredvalue: heygen:voice@1.0

Send auto instead of an AIR identifier to have the model router choose the model for this task. The rest of the request is unchanged, every value you send is kept, and only the parameters you leave out are filled in. See Model Router.

Learn more3 resources

speech objectrequired

Settings for speech generation.

Properties3 properties

speech » text text stringrequiredmin: 1max: 5000: Text to convert to speech. Plain text only, so SSML and <break> tags are not supported.

speech » voice voice string

Voice identifier to use for speech generation. A public HeyGen voice, or the outputs.voiceId of an earlier inputs.audio request from the same organization.

Allowed values24 values

: Bram, calm and gentle.
: Cecily, warm and friendly.
: Corinne, bright and energetic.
: Elowen, warm and soothing.
: Ewan, bright and energetic.
: Felicity, upbeat and lively.
: Gareth, conversational and easygoing.
: Hugh, firm and measured.
: Iona, bright and energetic.
: Jocelyn, bright and energetic.
: Jonah, clear and professional.
: Kieran, warm and friendly.
: Lucian, conversational and easygoing.
: Marielle, upbeat and lively.
: Meredith, serious and composed.
: Nadine, calm and gentle.
: Noelle, warm and soothing.
: Rory, upbeat and lively.
: Sabrina, upbeat and lively.
: Simon, calm and gentle.
: Soren, firm and measured.
: Tabitha, conversational and easygoing.
: Vincent, thoughtful and clear.
: Weston, warm and friendly.

speech » language language stringmin: 1: Language code for speech generation. Detected from speech.text when omitted.
Allowed values39 values

Settings

Technical parameters to fine-tune the inference process. These must be nested inside the settings object.

settings » expressiveness expressiveness floatmin: 0max: 1step: 0.01default: 1: Expressiveness of the delivery.