Chirp 3 vs Seed ASR
Which one, when — curated verdict, not a benchmark table
Both bill per audio minute and both diarize; seed-asr-bigmodel is 8x cheaper at $0.002 against $0.016 and takes far longer files — up to 5 hours and 512MB in its async mode, against an hour for chirp-3's batch mode — with sentence and word timestamps. chirp-3 answers with breadth instead: 29 GA plus 82 preview locales, against a default set of Mandarin, English, Cantonese and Chinese dialects on seed-asr-bigmodel with 39 language keys pinnable explicitly. Pick on recording length and locale, not on price.
Pricing
Rates from the live catalog at build time; each model page carries the current card.
Where they sit — price per audio minute across all 11 speech-to-text models on this billing unit (log scale)
Capabilities
Specs
| Chirp 3 | Seed ASR | |
|---|---|---|
| Input modalities | audio | audio |
| Output modalities | text | text |
| Released | 2025-10-13 | — |
| Limits | Auto-detected audio decoding sync Recognize <1 min, BatchRecognize 1 min–1 hr (<=20 min with word timestamps), StreamingRecognize for real-time speaker diarization in BatchRecognize and Recognize (14 languages) utterance-level timestamps (StreamingRecognize only), word-level timestamps listed as unsupported language-agnostic transcription 29 GA + 82 preview locales | Async audio-file mode: <512MB, <5 hours, OPUS/WAV/MP3/SPX/OGG/AMR/AAC/M4A (raw PCM also accepted), results returned within 3 hours and retained 7 days speaker diarization via enable_speaker_info (audio-file API only, best with <=10 speakers, no diarization on the streaming API) sentence + word segmentation with start_time/end_time via show_utterances language identification via enable_lid hotwords/context up to 800 tokens and 20 rounds per-call billing |
| Languages | 29 GA + 82 Preview locales (111 total) across StreamingRecognize, Recognize and BatchRecognize diarization covers 14 of them | With `language` empty the model covers Mandarin, English, Cantonese, Shanghainese, Minnan, Sichuan and Shaanxi dialects 39 language keys can be pinned explicitly (en-US, zh-CN, yue-CN, ja-JP, ko-KR, id-ID, es-MX, pt-BR, de-DE, fr-FR, fil-PH, ms-MY, th-TH, ar-SA, it-IT, bn-BD, el-GR, nl-NL, ru-RU, tr-TR, vi-VN, pl-PL, ro-RO, uk-UA, az-AZ, bg-BG, cs-CZ, da-DK, fi-FI, hi-IN, hu-HU, kk-KZ, km-KH, my-MM, no-NO, pa-PK, sv-SE, sw-KE, ur-PK), plus optional auto-detection (enable_auto_lang) |
Specs are transcribed from each vendor’s documentation; a row a vendor does not publish is left out rather than inferred. Full sources: Chirp 3 · Seed ASR
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="chirp-3",
# model="seed-asr-bigmodel", # 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: "chirp-3",
// model: "seed-asr-bigmodel", // 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="chirp-3" \
# -F model="seed-asr-bigmodel" \ # 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: "chirp-3",
// Model: "seed-asr-bigmodel", // 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("chirp-3")
// .model("seed-asr-bigmodel") // uncomment this line, comment the one above
.file(Paths.get("meeting.mp3"))
.build()).asTranscription();
System.out.println(resp.text());FAQ
Which is cheaper, Chirp 3 or Seed ASR?
Seed ASR is cheaper on per audio minute ($0.002 vs $0.016, 8.0× 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 Chirp 3 against Seed ASR 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.
Do Chirp 3 and Seed ASR support speaker diarization?
The capability table above answers this per model, straight from each vendor’s documentation — diarization, streaming and timestamps are listed separately because models differ on all three.