Seed ASR
Provider list prices: no platform markup, pay-as-you-go. These are official list prices. Logged-in customers may see effective prices including workspace discounts on /console/pricing.
Use Seed ASR in 30 seconds
OpenAI-compatible: swap the base_url, keep your SDK. POST /v1/audio/transcriptions
from openai import OpenAI
client = OpenAI(
base_url="https://synthorai.io/v1",
api_key="sk-syn-...",
)
resp = client.audio.transcriptions.create(
model="seed-asr-bigmodel",
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: "seed-asr-bigmodel",
file: fs.createReadStream("meeting.mp3"),
});
console.log(resp.text);curl https://synthorai.io/v1/audio/transcriptions \
-H "Authorization: Bearer sk-syn-..." \
-F model="seed-asr-bigmodel" \
-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: "seed-asr-bigmodel",
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("seed-asr-bigmodel")
.file(Paths.get("meeting.mp3"))
.build()).asTranscription();
System.out.println(resp.text());About Seed ASR
seed-asr-bigmodel is ByteDance's Seed-ASR large-model speech recognition service on BytePlus, exposed through the audio-file recognition API as the bigmodel engine.
- It transcribes recordings asynchronously via a submit-and-query flow suited to batch and offline workloads, recognizing Mandarin, English, Cantonese, and several Chinese dialects by default, with dozens of settable languages from Japanese to Arabic and optional automatic language detection.
- Hotword biasing and conversational context improve accuracy, and Seed ASR 2.0 extends that context to an accompanying image.
- Synthorai wraps it in an OpenAI-compatible transcription endpoint.
Specs & limits
| Modalities | audio → text |
| Features | streaming |
| Audio limits | wav/mp3/ogg (raw PCM also accepted); async submit+query flow for long audio files plus a streaming ASR variant; hotwords/context up to 800 tokens and 20 rounds; Seed ASR 2.0 additionally accepts 1 context image (<=500KB JPEG/PNG); per-call billing |
| Notable | No official model id 'seed-asr-bigmodel': BytePlus Seed Speech uses model_name 'bigmodel' with resource ids volc.bigasr.auc (Seed ASR 1.0) / volc.seedasr.auc (Seed ASR 2.0). |
FAQ
Is the Seed ASR API free to try?
Yes: new accounts get 10 trial calls and up to $1 in free credit, no card required. That's enough to try Seed ASR against your real workload before adding a payment method.
What is Seed ASR best at?
Asynchronous submit-and-query batch transcription, plus dozens of settable languages with auto-detection and conversational context extends to an accompanying image. See the About section for the full picture from the vendor's own release notes.
How much does Seed ASR cost?
Seed ASR costs $0.002 per minute of audio transcribed on Synthorai: pay-as-you-go, no platform markup, no subscription.
Which languages does Seed ASR support?
On Synthorai you call Seed ASR through POST /v1/audio/transcriptions, the OpenAI transcription API shape. Official language list →
How do I get access to Seed ASR?
Point your existing OpenAI SDK at base_url="https://synthorai.io/v1", set model="seed-asr-bigmodel", and you're done. One API key covers every model on the gateway.