bytedance/seed-speech/tts/2.0

Name: Bytedance Seed Speech Text to Speech
Author: Bytedance

Seed Speech Tts 2.0 is Bytedance's text-to-speech AI model. Generate human-like voiceovers with expressive intonation, multilingual support, and customizable voice characteristics.

Input

Text(string)

The text to synthesize into speech.

Output Format(string)

Output audio format. 'mp3' returns MP3 audio; 'opus' returns Opus audio in an Ogg container. Allowed values: mp3, opus.

Sample Rate(integer)

Sample rate of the output audio in Hz. Allowed values: 8000, 16000, 22050, 24000, 32000, 44100, 48000.

Volume(number)

0.52

Volume. 1.0 is normal volume, 0.5 is half, 2.0 is double. Range: 0.5 to 2.

Voice(string)

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. Allowed 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.

Pitch(integer)

-1212

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

Language(string)

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). Allowed 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.

Speed(number)

0.52

Speech speed. 1.0 is normal speed, 0.5 is half speed, 2.0 is double speed. Range: 0.5 to 2.

Idle

Example output — click Run to generate your own

Production endpoint

Send your first request

OpenAI-compatible endpoint with unified authentication and usage tracking.

POSThttps://api.sandbase.ai/v1/run

Model IDbytedance/seed-speech/tts/2.0

Input Schema

9 parameters · 0 required · 9 optional

Parameter	Type	Required	Description
`text`	string	Optional	The text to synthesize into speech. · Max length: 5000
`pitch`	integer	Optional	Voice pitch shift in semitones. 0 is normal pitch, -12 lowers by one octave, 12 raises by one octave. · Min: -12 · Max: 12 · Default: 0
`speed`	number	Optional	Speech speed. 1.0 is normal speed, 0.5 is half speed, 2.0 is double speed. · Min: 0.5 · Max: 2 · Default: 1
`voice`	string	Optional	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. · Options: 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 · Default: "stokie_en" vivi_mixed_en_zh_ja_es_idmindy_en_es_id_pt_zhstokie_endacey_entim_enkian_en_zhcedric_en_zhsophie_en_zhjean_en_zhmagnus_en_zhmabel_en_zhnadia_en_zhopal_en_zhpearl_en_zhquentin_en_zhvienna_mixed_en_zhalina_mixed_en_zhcorinne_mixed_en_zhesther_mixed_en_zhfreya_mixed_en_zhgigi_mixed_en_zhholly_mixed_en_zhlyla_mixed_en_zhdaisy_mixed_en_zhtracy_es_zhjess_ja_es_id_pt_en_zhpinky_es_ko_mixed_en_zhsweety_ja_essandy_es_mixed_en_zhsven_deminimi_jausseau_frfelipe_eshan_idmartins_ptenzo_itshane_kobonnie_zhfelix_zhceleste_zhmonkey_king_zh
`volume`	number	Optional	Volume. 1.0 is normal volume, 0.5 is half, 2.0 is double. · Min: 0.5 · Max: 2 · Default: 1
`language`	string	Optional	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). · Options: zh, en, ja, es-mx, id, pt-br, ko, it, de, fr zhenjaes-mxidpt-brkoitdefr
`sample_rate`	integer	Optional	Sample rate of the output audio in Hz. · Options: 8000, 16000, 22050, 24000, 32000, 44100, 48000 · Default: 24000 8000160002205024000320004410048000
`output_format`	string	Optional	Output audio format. 'mp3' returns MP3 audio; 'opus' returns Opus audio in an Ogg container. · Options: mp3, opus · Default: "mp3" mp3opus
`voice_instruction`	string	Optional	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.

Output Schema

Field	Type	Description
`id`	string	Unique identifier for the generation task
`status`	string	Task status: pending, running, completed, failed, timeout
`model`	string	Model used for the generation
`outputs`	array	Array of output items
`outputs[].url`	string	URL of the generated artifact
`outputs[].content_type`	string	MIME type (e.g. image/png, video/mp4)
`error`	object \| null	Error details if failed, null on success
`error.type`	string	Machine-readable error type code
`error.message`	string	Human-readable error description

Async Workflow

This model uses asynchronous execution. Submit a request and poll for the result.

Submit — POST to /v1/run, receive an id
Poll — GET /v1/run/{id} until status is completed, failed, or timeout
Retrieve — Read outputs from the completed response

Code Examples

Ready-to-run snippets

# Step 1: Submit
curl -X POST https://api.sandbase.ai/v1/run \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
  "model": "bytedance/seed-speech/tts/2.0",
  "text": "Hello, this is a test of ByteDance TTS 2.0 speech synthesis.",
  "pitch": 0,
  "speed": 1,
  "voice": "stokie_en",
  "volume": 1,
  "sample_rate": 24000,
  "output_format": "mp3",
  "voice_instruction": "Speak in a warm, cheerful tone.",
  "prompt": "a beautiful sunset over mountains"
}'

# Step 2: Poll result (replace <id>)
curl https://api.sandbase.ai/v1/run/<id> \
  -H "Authorization: Bearer YOUR_API_KEY"

← Back to Bytedance Seed Speech Text to Speech

API README

PRICED DRAFT — MANUAL REVIEW REQUIRED exact_model_mode: bytedance/seed-speech/tts/2.0 original_unit: method: per-started-1000-characters price result_base_price: 0.03 result_price_formula: Math.ceil(len(params.text) / 1000) * 0.03 review_status: pending; model remains disabled checked_at: 2026-08-16

More Models by Bytedance

bytedance/seedance/2.0/image-to-videoByteDance's most advanced image-to-video model transforming still images into cinematic video with native audio, multi-shot editing, and director-level camera control for professional-grade video cre...Pay per use bytedance/seedream/4.5/editA new-generation image creation model from ByteDance, Seedream 4.5 integrates text-to-image generation and image editing into a single unified architecture, delivering high-fidelity visuals, precise p...Pay per use bytedance/seedance/2.0/reference-to-videoByteDance's most advanced reference-to-video model generating cinematic video guided by reference content, with native audio, multi-shot editing, and director-level camera control for professional-gr...Pay per use bytedance/seedvr/upscale/imageSeedvr Upscale Image by Bytedance - AI-powered image editing, style transfer, and transformation. Edit photos with natural language instructions, remove backgrounds, change styles, and enhance images ...Pay per use bytedance/seedream/5.0/lite/editSeedream 5.0 Lite — Fast Text-to-Image API The lightweight version of Seedream 5.0, delivering high-quality, low-latency AI image generation from text prompts. Ideal for real-time creative tools, e-co...Pay per use bytedance/seedance/2.0/text-to-videoByteDance's most advanced text-to-video model delivering cinematic output, native audio, multi-shot editing, and director-level camera control for professional-grade video creation.Pay per use bytedance/seedream/4.5A new-generation image creation model from ByteDance, Seedream 4.5 integrates text-to-image generation and image editing into a single unified architecture, delivering high-fidelity visuals, precise p...Pay per use bytedance/seedance/2.0/fast/image-to-videoByteDance's most advanced image-to-video model in its fast tier delivering lower latency and cost without compromising on cinematic output, native audio, multi-shot editing, and director-level camera...Pay per use