Qwen3 TTS Instruct Flash vs TTS-1 HD
Which one, when — curated verdict, not a benchmark table
qwen3-tts-instruct-flash costs $11.5 per million characters against $30, roughly 2.6x less, and it is the only one of the two that lets you direct the voice in natural language — tts-1-hd exposes no voice control. The trade is request size, 600 characters against 4096, so long copy has to be split. Both stream. Pick tts-1-hd for long passages in one call, qwen3-tts-instruct-flash for directed short lines at lower cost.
Pricing
| Qwen3 TTS Instruct Flash | TTS-1 HD | Δ | |
|---|---|---|---|
| Per 1M characters | $11.5 | $30 | 0.38× |
Rates from the live catalog at build time; each model page carries the current card.
Where they sit — price per 1M characters across all 7 text-to-speech models on this billing unit (log scale)
Capabilities
| Qwen3 TTS Instruct Flash | TTS-1 HD | |
|---|---|---|
| Streaming | yes | yes |
| SSML | undocumented | undocumented |
| Billing unit | character | character |
Specs
| Qwen3 TTS Instruct Flash | TTS-1 HD | |
|---|---|---|
| Input modalities | text | text |
| Output modalities | audio | audio |
| Request limit | 600 characters | 4096 characters |
| Voices | 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. | alloy, ash, coral, echo, fable, onyx, nova, sage and shimmer, a smaller set than the full 13-voice TTS list, and voices are currently optimized for English. |
| Languages | 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). | Generally follows the Whisper model’s language support: Afrikaans, Arabic, Armenian, Azerbaijani, Belarusian, Bosnian, Bulgarian, Catalan, Chinese, Croatian, Czech, Danish, Dutch, English, Estonian, Finnish, French, Galician, German, Greek, Hebrew, Hindi, Hungarian, Icelandic, Indonesian, Italian, Japanese, Kannada, Kazakh, Korean, Latvian, Lithuanian, Macedonian, Malay, Marathi, Maori, Nepali, Norwegian, Persian, Polish, Portuguese, Romanian, Russian, Serbian, Slovak, Slovenian, Spanish, Swahili, Swedish, Tagalog, Tamil, Thai, Turkish, Ukrainian, Urdu, Vietnamese and Welsh, despite voices being optimized for English |
| Voice control |
| none |
| Limits | 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. | Speech generation endpoint (v1/audio/speech) only, with Chat Completions, Responses, Realtime, Batch and Fine-tuning all listed as not supported input text is capped at 4096 characters output mp3 (default), opus, aac, flac, wav or pcm (raw 24 kHz 16-bit signed little-endian samples) realtime playback via chunked transfer encoding |
Specs are transcribed from each vendor’s documentation; a row a vendor does not publish is left out rather than inferred. Full sources: Qwen3 TTS Instruct Flash · TTS-1 HD
Switch between them with one line
Both ids are in every tab below — the highlighted pair of lines is the only edit. Same endpoint, same key, same request shape.
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="tts-1-hd", # uncomment this line, comment the one above
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: "tts-1-hd", // uncomment this line, comment the one above
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="tts-1-hd" \ # uncomment this line, comment the one above
-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: "tts-1-hd", // uncomment this line, comment the one above
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("tts-1-hd") // uncomment this line, comment the one above
.file(Paths.get("meeting.mp3"))
.build()).asTranscription();
System.out.println(resp.text());FAQ
Which is cheaper, Qwen3 TTS Instruct Flash or TTS-1 HD?
Qwen3 TTS Instruct Flash is cheaper on per 1m characters ($11.5 vs $30, 2.6× apart). Other rows may point the other way — the table above carries the full card, and real cost depends on your mix.
Can I A/B test Qwen3 TTS Instruct Flash against TTS-1 HD without two integrations?
Yes. Both are served through the same OpenAI-compatible endpoint with one API key — switching is a one-line model-string change, so you can route a fraction of traffic to each and compare bills directly.
How is text-to-speech billed?
Per character of input text, with a per-request character ceiling shown in the spec table. Long scripts must be chunked across requests on either model.