Qwen3 TTS Instruct Flash vs BytePlus Seed TTS 2.0
何時該用哪一個 — 綜合評斷，而非基準測試數據表
qwen3-tts-instruct-flash 每百萬字元便宜 2.6 倍（$11.5 對 $30），兩者也都接受自然語言的音色指令，但請求長度差別很大：600 個字元對 4096。seed-tts-2.0 還在描述式控制之外提供數值型語音參數，並按場景分組公布音色。短句要控成本選 qwen3-tts-instruct-flash，長段落和更細的音色控制選 seed-tts-2.0。
定價
| Qwen3 TTS Instruct Flash | BytePlus Seed TTS 2.0 | Δ | |
|---|---|---|---|
| 每 1M 字元 | $11.5 | $30 | 0.38× |
費率取自建置時的即時目錄；各模型頁面皆附有目前的費率卡。
它們的相對位置 — 在此計費單位下，所有 7 個 文字轉語音 模型的 每 1M 字元的價格（對數尺度）
能力
| Qwen3 TTS Instruct Flash | BytePlus Seed TTS 2.0 | |
|---|---|---|
| 串流 | 是 | 是 |
| SSML | undocumented | unsupported |
| 計費單位 | character | character |
規格
| Qwen3 TTS Instruct Flash | BytePlus Seed TTS 2.0 | |
|---|---|---|
| 輸入模態 | 文字 | 文字 |
| 輸出模態 | 音訊 | 音訊 |
| 請求限制 | 600 characters | — |
| 語音 | System voices published with one-line personas, among them Cherry (a sunny, positive, friendly and natural young woman), Serena, Ethan, Chelsie, Momo, Vivian, Moon, Maia, Kai, Nofish (a designer who cannot pronounce retroflex sounds), Bella, Eldric Sage, Mia, Mochi, Bellona, Vincent, Bunny, Neil, Elias, Arthur, Nini, Seren, Pip and Stella the Qwen-TTS voice list pairs each voice with the exact model ids that accept it. | TTS 2.0 voices carry *_uranus_bigtts speaker IDs and are listed by scenario (General, Entertainment, Education, Dubbing, AudioBook, RolePlay, CustomerService) on the Voice List page per-voice emotion via audio_params.emotion with emotion_scale 1 to 5 (default 4), speech_rate and loudness_rate in [-50, 100], and post_process.pitch in [-12, 12]. |
| 語言 | Chinese (Mandarin), English, German, Italian, Portuguese, Spanish, Japanese, Korean, French and Russian. language_type defaults to Auto for mixed-language or undetermined input, which Alibaba documents as not guaranteeing accuracy naming a single language is documented to significantly improve synthesis quality. Unlike the Qwen3-TTS-Flash series, the Instruct series lists no Chinese dialect voices (Beijing, Shanghainese, Sichuan, Nanjing, Shaanxi, Hokkien, Tianjin, Cantonese). | English, Chinese, Japanese, German, French, Mexican Spanish, Indonesian Bahasa, Brazilian Portuguese, Italian and Korean |
| 語音控制 |
| context_texts and section_id are TTS 2.0 only: a plain-language instruction steers rate, emotion, volume and style (only the first list value takes effect, and its text is not billed), and section_id links up to 30 rounds or 10 minutes of earlier synthesis as historical context. |
| 限制 | HTTP non-real-time speech synthesis API the -realtime suffix marks the WebSocket sibling. Input text capped at 600 characters, multilingual mixed input allowed. Non-streaming returns an audio file URL valid for 24 hours streaming returns Base64-encoded PCM in chunks with the URL only in the final packet, played back in the official samples as 24 kHz mono 16-bit audio. Billed by input text characters, reported as usage.characters (input_tokens and output_tokens are always 0 on the Qwen3-TTS series) output audio is free. | Integration via uni-directional streaming HTTP, uni- or bi-directional streaming WebSocket and online SDK sampling rate 24K/16K/8K on the uni-directional streaming and non-streaming interfaces, 48K/24K/16K/8K on the bi-directional interface output PCM, OGG_OPUS or MP3 (WAV is accepted but returns multiple headers when streaming) SSML is not supported |
規格摘錄自各供應商的文件；供應商未發布的資料列會直接省略，而非自行推測。 完整來源： Qwen3 TTS Instruct Flash · BytePlus Seed TTS 2.0
只需一行程式碼即可在兩者間切換
以下每個頁籤中都有這兩個 ID — 醒目提示的這兩行是唯一的修改處。相同的端點，相同的金鑰，相同的請求結構。
from openai import OpenAI
client = OpenAI(
base_url="https://synthorai.io/v1",
api_key="sk-syn-...",
)
resp = client.audio.transcriptions.create(
model="qwen3-tts-instruct-flash",
# model="seed-tts-2.0", # 取消註解此行，並註解上一行
file=open("meeting.mp3", "rb"),
language="en",
)
print(resp.text)import OpenAI from "openai";
import fs from "node:fs";
const client = new OpenAI({
baseURL: "https://synthorai.io/v1",
apiKey: "sk-syn-...",
});
const resp = await client.audio.transcriptions.create({
model: "qwen3-tts-instruct-flash",
// model: "seed-tts-2.0", // 取消註解此行，並註解上一行
file: fs.createReadStream("meeting.mp3"),
});
console.log(resp.text);curl https://synthorai.io/v1/audio/transcriptions \
-H "Authorization: Bearer sk-syn-..." \
-F model="qwen3-tts-instruct-flash" \
# -F model="seed-tts-2.0" \ # 取消註解此行，並註解上一行
-F file=@meeting.mp3package main
import (
"context"
"fmt"
"os"
"github.com/openai/openai-go/v3"
"github.com/openai/openai-go/v3/option"
)
func main() {
client := openai.NewClient(
option.WithBaseURL("https://synthorai.io/v1"),
option.WithAPIKey("sk-syn-..."),
)
f, _ := os.Open("meeting.mp3")
resp, _ := client.Audio.Transcriptions.New(context.TODO(), openai.AudioTranscriptionNewParams{
Model: "qwen3-tts-instruct-flash",
// Model: "seed-tts-2.0", // 取消註解此行，並註解上一行
File: f,
})
fmt.Println(resp.Text)
}import com.openai.client.OpenAIClient;
import com.openai.client.okhttp.OpenAIOkHttpClient;
import com.openai.models.audio.transcriptions.*;
import java.nio.file.Paths;
OpenAIClient client = OpenAIOkHttpClient.builder()
.baseUrl("https://synthorai.io/v1")
.apiKey("sk-syn-...")
.build();
Transcription resp = client.audio().transcriptions().create(
TranscriptionCreateParams.builder()
.model("qwen3-tts-instruct-flash")
// .model("seed-tts-2.0") // 取消註解此行，並註解上一行
.file(Paths.get("meeting.mp3"))
.build()).asTranscription();
System.out.println(resp.text());常見問題
Qwen3 TTS Instruct Flash 和 BytePlus Seed TTS 2.0 哪個比較便宜？
Qwen3 TTS Instruct Flash 在 每 1m 字元 上較便宜（$11.5 對比 $30，相差 2.6×）。其他項目可能呈現相反結果 — 上表提供完整資訊，實際成本取決於您的使用組合。
我可以在不進行兩次整合的情況下，對 Qwen3 TTS Instruct Flash 和 BytePlus Seed TTS 2.0 進行 A/B 測試嗎？
可以。兩者皆透過同一個相容 OpenAI 的端點提供服務，並使用同一把 API 金鑰 — 切換只需更改一行的模型字串，因此您可以將部分流量分別導向兩者並直接比較帳單。
文字轉語音是如何計費的？
依輸入文字的字元數計費，規格表中會顯示每個請求的字元上限。較長的稿件在這兩個模型上都必須分拆成多個請求。