Seed Speech developed by ByteDance, is a family of large-scale text-to-speech models capable of synthesizing speech that is virtually indistinguishable from human speech.

fal-ai/bytedance/seed-speech/tts/v2

Seed Speech developed by ByteDance, is a family of large-scale text-to-speech models capable of synthesizing speech that is virtually indistinguishable from human speech.

Inference

Commercial use

Partner

Schema

LLMs

Playground API Examples

Loading API documentation…

fal-ai/bytedance/seed-speech/tts/v2

Schema

LLMs

Loading API documentation…

Bytedance Seed Speech Text to Speech API Docs | fal

Seed Speech developed by ByteDance, is a family of large-scale text-to-speech models capable of synthesizing speech that is virtually indistinguishable from human speech.

fal-ai/bytedance/seed-speech/tts/v2

Seed Speech developed by ByteDance, is a family of large-scale text-to-speech models capable of synthesizing speech that is virtually indistinguishable from human speech.

Inference

Commercial use

Partner

Schema

LLMs

Playground API Examples

About

Generate speech from text using ByteDance TTS 2.0.

1. Calling the API#

Install the client#

The client provides a convenient way to interact with the model API.

npm install --save @fal-ai/client

Migrate to @fal-ai/client

The @fal-ai/serverless-client package has been deprecated in favor of @fal-ai/client. Install the new package and update your imports — see client setup.

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.

export FAL_KEY="YOUR_API_KEY"

Submit a request#

The client API handles the API submit protocol. It will handle the request status updates and return the result when the request is completed.

import { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/bytedance/seed-speech/tts/v2", {
  input: {
    text: "Hello, this is a test of ByteDance TTS 2.0 speech synthesis."
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);

2. Authentication#

The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.

API Key#

In an environment where you cannot set environment variables, you can configure the API key manually on the client.

import { fal } from "@fal-ai/client";

fal.config({
  credentials: "YOUR_FAL_KEY"
});

Protect your API Key

When running code on the client-side (e.g. in a browser, mobile app or GUI applications), make sure to not expose your FAL_KEY. Instead, use a server-side proxy to make requests to the API. For more information, check out our server-side integration guide.

3. Queue#

Long-running requests

For long-running requests, such as training jobs or models with slower inference times, it is recommended to check the Queue status and rely on Webhooks instead of blocking while waiting for the result.

Submit a request#

The client API provides a convenient way to submit requests to the model.

import { fal } from "@fal-ai/client";

const { request_id } = await fal.queue.submit("fal-ai/bytedance/seed-speech/tts/v2", {
  input: {
    text: "Hello, this is a test of ByteDance TTS 2.0 speech synthesis."
  },
  webhookUrl: "https://optional.webhook.url/for/results",
});

Fetch request status#

You can fetch the status of a request to check if it is completed or still in progress.

import { fal } from "@fal-ai/client";

const status = await fal.queue.status("fal-ai/bytedance/seed-speech/tts/v2", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
  logs: true,
});

Get the result#

Once the request is completed, you can fetch the result. See the Output Schema for the expected result format.

import { fal } from "@fal-ai/client";

const result = await fal.queue.result("fal-ai/bytedance/seed-speech/tts/v2", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);

4. Files#

Some attributes in the API accept file URLs as input. Whenever that's the case you can pass your own URL or a Base64 data URI.

Data URI (base64)#

You can pass a Base64 data URI as a file input. The API will handle the file decoding for you. Keep in mind that for large files, this alternative although convenient can impact the request performance.

Hosted files (URL)#

You can also pass your own URLs as long as they are publicly accessible. Be aware that some hosts might block cross-site requests, rate-limit, or consider the request as a bot.

Uploading files#

We provide a convenient file storage that allows you to upload files and use them in your requests. You can upload files using the client API and use the returned URL in your requests.

import { fal } from "@fal-ai/client";

const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);

Auto uploads

The client will auto-upload the file for you if you pass a binary object (e.g. File, Data).

Read more about file handling in our file upload guide.

5. Schema#

Input#

text string* required

The text to synthesize into speech.

voice VoiceEnum

Voice to use for synthesis. The preset name encodes the voice and its supported language codes. 'mixed_en_zh' means the voice can seamlessly blend English and Chinese; separate codes (e.g. 'en_zh') mean the voice supports each language independently. Default value: "stokie_en"

Possible enum values: vivi_mixed_en_zh_ja_es_id, mindy_en_es_id_pt_zh, stokie_en, dacey_en, tim_en, kian_en_zh, cedric_en_zh, sophie_en_zh, jean_en_zh, magnus_en_zh, mabel_en_zh, nadia_en_zh, opal_en_zh, pearl_en_zh, quentin_en_zh, vienna_mixed_en_zh, alina_mixed_en_zh, corinne_mixed_en_zh, esther_mixed_en_zh, freya_mixed_en_zh, gigi_mixed_en_zh, holly_mixed_en_zh, lyla_mixed_en_zh, daisy_mixed_en_zh, tracy_es_zh, jess_ja_es_id_pt_en_zh, pinky_es_ko_mixed_en_zh, sweety_ja_es, sandy_es_mixed_en_zh, sven_de, minimi_ja, usseau_fr, felipe_es, han_id, martins_pt, enzo_it, shane_ko, bonnie_zh, felix_zh, celeste_zh, monkey_king_zh

output_format OutputFormatEnum

Output audio format. 'mp3' returns MP3 audio; 'opus' returns Opus audio in an Ogg container. Default value: "mp3"

Possible enum values: mp3, opus

sample_rate SampleRateEnum

Sample rate of the output audio in Hz. Default value: "24000"

Possible enum values: 8000, 16000, 22050, 24000, 32000, 44100, 48000

speed float

Speech speed. 1.0 is normal speed, 0.5 is half speed, 2.0 is double speed. Default value: 1

volume float

Volume. 1.0 is normal volume, 0.5 is half, 2.0 is double. Default value: 1

pitch integer

Voice pitch shift in semitones. 0 is normal pitch, -12 lowers by one octave, 12 raises by one octave.

language Enum

Force the text to be read as a single language, disabling automatic language detection. Leave unset for automatic detection (including seamless Chinese/English mixing on bilingual voices). Codes: zh (Chinese), en (English), ja (Japanese), es-mx (Mexican Spanish), id (Indonesian), pt-br (Brazilian Portuguese), ko (Korean), it (Italian), de (German), fr (French).

Possible enum values: zh, en, ja, es-mx, id, pt-br, ko, it, de, fr

voice_instruction string

Optional natural-language instruction that steers the delivery (tone, emotion, pace, volume), e.g. 'Speak in a cheerful tone' or 'Could you speak a bit slower?'. It is not spoken aloud and does not affect billing.

{
  "text": "Hello, this is a test of ByteDance TTS 2.0 speech synthesis.",
  "voice": "stokie_en",
  "output_format": "mp3",
  "sample_rate": 24000,
  "speed": 1,
  "volume": 1,
  "voice_instruction": "Speak in a warm, cheerful tone."
}

Output#

audio File* required

The generated audio file.

{
  "audio": {
    "url": "https://v3b.fal.media/files/b/0a9abcc6/Si0ucRYji4wPj7Z2H2XFL_audio.mp3"
  }
}

Other types#

File#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

Loading API documentation…

1. Calling the API

2. Authentication

API Key

3. Queue

4. Files

5. Schema

About

Generate speech from text using ByteDance TTS 2.0.

1. Calling the API#

Install the client#

The client provides a convenient way to interact with the model API.

npm install --save @fal-ai/client

Migrate to @fal-ai/client

The @fal-ai/serverless-client package has been deprecated in favor of @fal-ai/client. Install the new package and update your imports — see client setup.

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.

export FAL_KEY="YOUR_API_KEY"

Submit a request#

The client API handles the API submit protocol. It will handle the request status updates and return the result when the request is completed.

import { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/bytedance/seed-speech/tts/v2", {
  input: {
    text: "Hello, this is a test of ByteDance TTS 2.0 speech synthesis."
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);

2. Authentication#

The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.

API Key#

In an environment where you cannot set environment variables, you can configure the API key manually on the client.

import { fal } from "@fal-ai/client";

fal.config({
  credentials: "YOUR_FAL_KEY"
});

Protect your API Key

3. Queue#

Long-running requests

Submit a request#

The client API provides a convenient way to submit requests to the model.

import { fal } from "@fal-ai/client";

const { request_id } = await fal.queue.submit("fal-ai/bytedance/seed-speech/tts/v2", {
  input: {
    text: "Hello, this is a test of ByteDance TTS 2.0 speech synthesis."
  },
  webhookUrl: "https://optional.webhook.url/for/results",
});

Fetch request status#

You can fetch the status of a request to check if it is completed or still in progress.

import { fal } from "@fal-ai/client";

const status = await fal.queue.status("fal-ai/bytedance/seed-speech/tts/v2", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
  logs: true,
});

Get the result#

Once the request is completed, you can fetch the result. See the Output Schema for the expected result format.

import { fal } from "@fal-ai/client";

const result = await fal.queue.result("fal-ai/bytedance/seed-speech/tts/v2", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);

4. Files#

Some attributes in the API accept file URLs as input. Whenever that's the case you can pass your own URL or a Base64 data URI.

Data URI (base64)#

Hosted files (URL)#

You can also pass your own URLs as long as they are publicly accessible. Be aware that some hosts might block cross-site requests, rate-limit, or consider the request as a bot.

Uploading files#

We provide a convenient file storage that allows you to upload files and use them in your requests. You can upload files using the client API and use the returned URL in your requests.

import { fal } from "@fal-ai/client";

const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);

Auto uploads

The client will auto-upload the file for you if you pass a binary object (e.g. File, Data).

Read more about file handling in our file upload guide.

5. Schema#

Input#

text string* required

The text to synthesize into speech.

voice VoiceEnum

output_format OutputFormatEnum

Output audio format. 'mp3' returns MP3 audio; 'opus' returns Opus audio in an Ogg container. Default value: "mp3"

Possible enum values: mp3, opus

sample_rate SampleRateEnum

Sample rate of the output audio in Hz. Default value: "24000"

Possible enum values: 8000, 16000, 22050, 24000, 32000, 44100, 48000

speed float

Speech speed. 1.0 is normal speed, 0.5 is half speed, 2.0 is double speed. Default value: 1

volume float

Volume. 1.0 is normal volume, 0.5 is half, 2.0 is double. Default value: 1

pitch integer

Voice pitch shift in semitones. 0 is normal pitch, -12 lowers by one octave, 12 raises by one octave.

language Enum

Possible enum values: zh, en, ja, es-mx, id, pt-br, ko, it, de, fr

voice_instruction string

{
  "text": "Hello, this is a test of ByteDance TTS 2.0 speech synthesis.",
  "voice": "stokie_en",
  "output_format": "mp3",
  "sample_rate": 24000,
  "speed": 1,
  "volume": 1,
  "voice_instruction": "Speak in a warm, cheerful tone."
}

Output#

audio File* required

The generated audio file.

{
  "audio": {
    "url": "https://v3b.fal.media/files/b/0a9abcc6/Si0ucRYji4wPj7Z2H2XFL_audio.mp3"
  }
}

Other types#

File#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

fal-ai/bytedance/seed-speech/tts/v2

fal-ai/bytedance/seed-speech/tts/v2

fal-ai/bytedance/seed-speech/tts/v2

Table of contents

1. Calling the API

2. Authentication

3. Queue

4. Files

5. Schema

About

1. Calling the API#

Install the client#

Migrate to @fal-ai/client

Setup your API Key#

Submit a request#

2. Authentication#

API Key#

Protect your API Key

3. Queue#

Long-running requests

Submit a request#

Fetch request status#

Get the result#

4. Files#

Data URI (base64)#

Hosted files (URL)#

Uploading files#

Auto uploads

5. Schema#

Input#

Output#

Other types#

File#

Table of contents

1. Calling the API

2. Authentication

3. Queue

4. Files

5. Schema

About

1. Calling the API#

Install the client#

Migrate to @fal-ai/client

Setup your API Key#

Submit a request#

2. Authentication#

API Key#

Protect your API Key

3. Queue#

Long-running requests

Submit a request#

Fetch request status#

Get the result#

4. Files#

Data URI (base64)#

Hosted files (URL)#

Uploading files#

Auto uploads

5. Schema#

Input#

Output#

Other types#

File#