Seedance 1.5 Pro is ByteDance's audio-visual sync video generation model on BytePlus ModelArk, described officially as purpose-built for native, joint audio-video generation, covering text-to-video plus first-frame and first-and-last-frame image-to-video.
- Input
- text image
- Output
- video $2.4/M
Benchmarks
Seedance 1.5 Pro: 12 published, but no benchmark it shares with enough other models to compare.
Vendor-published: ByteDance
Price in context
Where the price sits among 5 comparable models
The bar shows how this model’s price compares with every other model of the same kind on Synthorai. The cheapest and the most expensive are named at each end. These are base rates; batch, region and cache-write discounts are on the pricing page.
Specs & limits
Video
| Resolution | 480p / 720p / 1080p A fixed set of options, not a range. |
|---|---|
| Clip length | 4-12 s A continuous range, not a fixed set. |
| Frame rate | 24 fps |
| Aspect ratios | 6 (incl. 16:9, 9:16, 1:1) |
| Video inputs | text-to-video · first-frame & first/last-frame image-to-video |
| Native audio | Yes, generates sound |
| Format | .mp4 |
Model
| Modalities | text + image → video |
|---|
- Audio-visual sync video generation: text-to-video + first-frame and first-and-last-frame image-to-video at 480p/720p/1080p, 24 fps, 4-12 s, six aspect ratios, .mp4
- generate_audio toggles sound-on vs silent output at separate per-token rates
- the only Seedance with draft mode (reduced-token 480p quick preview)
- version date 251215 encoded in the model id
One prompt, measured through the gateway
Seedance 1.5 Pro
Model returned 1280×720 Length 5s latency 49 s
One prompt, one request per model, no retries and no cherry-picking - the first result each model returned. Neither size nor duration was pinned: each model used its own default, because a request shaped to fit all of them would flatter none. Files here are re-encoded for the web, so judge composition and prompt adherence, not compression.
Use Seedance 1.5 Pro in 30 seconds
Asynchronous job API: create a task and poll it, or hold the request open with Prefer: wait. POST /v1/videos
import time
import requests
BASE = "https://synthorai.io/v1"
HEADERS = {"Authorization": "Bearer sk-syn-..."}
# 1) create the video generation job (POST /v1/videos)
task = requests.post(
f"{BASE}/videos",
headers=HEADERS,
json={
"model": "seedance-1-5-pro-251215",
"prompt": "a watercolor lighthouse at dawn, waves rolling in, camera pulling back",
"resolution": "720p",
"duration": 5,
},
).json()
# 2) poll the job until it reaches a terminal state
while task["status"] in ("queued", "in_progress"):
time.sleep(5)
task = requests.get(f"{BASE}/videos/{task['id']}", headers=HEADERS).json()
# 3) completed → signed video URL (valid ~24h - download and store it promptly)
if task["status"] == "completed":
print(task["data"][0]["url"])
else:
print(task["error"])const HEADERS = {
Authorization: "Bearer sk-syn-...",
"Content-Type": "application/json",
};
interface VideoTask {
id: string;
status: "queued" | "in_progress" | "completed" | "failed" | "cancelled";
data?: Array<{ url: string }>;
error?: { code: string; message: string };
}
// 1) create the video generation job (POST /v1/videos)
const created = await fetch("https://synthorai.io/v1/videos", {
method: "POST",
headers: HEADERS,
body: JSON.stringify({
model: "seedance-1-5-pro-251215",
prompt: "a watercolor lighthouse at dawn, waves rolling in, camera pulling back",
resolution: "720p",
duration: 5,
}),
});
let task = (await created.json()) as VideoTask;
// 2) poll the job until it reaches a terminal state
while (task.status === "queued" || task.status === "in_progress") {
await new Promise((r) => setTimeout(r, 5000));
const res = await fetch(`https://synthorai.io/v1/videos/${task.id}`, { headers: HEADERS });
task = (await res.json()) as VideoTask;
}
// 3) completed → signed video URL (valid ~24h — download and store it promptly)
if (task.status === "completed") console.log(task.data?.[0]?.url);
else console.error(task.error);# Create the job; "Prefer: wait" holds the request up to 60s and returns the
# completed task when generation finishes in time (else the queued task).
curl https://synthorai.io/v1/videos \
-H "Authorization: Bearer sk-syn-..." \
-H "Content-Type: application/json" \
-H "Prefer: wait=60" \
-d '{
"model": "seedance-1-5-pro-251215",
"prompt": "a watercolor lighthouse at dawn, waves rolling in, camera pulling back",
"resolution": "720p",
"duration": 5
}'
# Still queued / in_progress? Poll until completed → data[0].url (valid ~24h).
curl https://synthorai.io/v1/videos/vid_9f2e8c1a4b7d \
-H "Authorization: Bearer sk-syn-..."package main
import (
"bytes"
"encoding/json"
"fmt"
"net/http"
"time"
)
const base = "https://synthorai.io/v1"
type videoTask struct {
ID string `json:"id"`
Status string `json:"status"`
Data []struct {
URL string `json:"url"`
} `json:"data"`
}
func call(method, url string, body []byte) (t videoTask) {
req, _ := http.NewRequest(method, url, bytes.NewReader(body))
req.Header.Set("Authorization", "Bearer sk-syn-...")
req.Header.Set("Content-Type", "application/json")
resp, _ := http.DefaultClient.Do(req)
defer resp.Body.Close()
json.NewDecoder(resp.Body).Decode(&t)
return t
}
func main() {
// 1) create the video generation job (POST /v1/videos)
payload, _ := json.Marshal(map[string]any{
"model": "seedance-1-5-pro-251215",
"prompt": "a watercolor lighthouse at dawn, waves rolling in, camera pulling back",
"resolution": "720p",
"duration": 5,
})
task := call("POST", base+"/videos", payload)
// 2) poll the job until it reaches a terminal state
for task.Status == "queued" || task.Status == "in_progress" {
time.Sleep(5 * time.Second)
task = call("GET", base+"/videos/"+task.ID, nil)
}
// 3) completed → signed video URL (valid ~24h — download and store promptly)
if task.Status == "completed" {
fmt.Println(task.Data[0].URL)
}
}import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
// JDK built-in HttpClient — no extra dependency needed.
HttpClient http = HttpClient.newHttpClient();
// 1) create the job; "Prefer: wait=60" holds the request up to 60s and
// returns the completed task when generation finishes in time
HttpRequest create = HttpRequest.newBuilder(URI.create("https://synthorai.io/v1/videos"))
.header("Authorization", "Bearer sk-syn-...")
.header("Content-Type", "application/json")
.header("Prefer", "wait=60")
.POST(HttpRequest.BodyPublishers.ofString("""
{"model": "seedance-1-5-pro-251215",
"prompt": "a watercolor lighthouse at dawn, waves rolling in, camera pulling back",
"resolution": "720p", "duration": 5}"""))
.build();
String task = http.send(create, HttpResponse.BodyHandlers.ofString()).body();
System.out.println(task); // {"id":"vid_…","status":…} — completed → data[0].url
// 2) still queued / in_progress? Poll GET https://synthorai.io/v1/videos/{id} until the
// status turns completed, then download data[0].url (valid ~24h).About Seedance 1.5 Pro
- BytePlus highlights millisecond-level lip sync for multi-speaker dialogue across Mandarin and several Chinese dialects as well as English, Japanese, Korean, Spanish, and Indonesian, alongside ambient sound, action foley, instruments, and background music.
- It outputs 480p, 720p, or 1080p .mp4 clips at 24 fps, 4-12 seconds long, in six aspect ratios, and accepts -1 as a duration to let the model choose.
- Its generate_audio switch selects sound-on or silent output, the two are billed at separate per-token rates with silent generation at half the audio rate, and audio is on by default, so the more expensive path is the one you get unless you opt out.
- It is also the only Seedance model with draft mode, a reduced-token 480p quick-preview option: drafts are 480p only, cannot return a last frame, and stay valid for seven days, after which promoting one to a final render reuses the draft's prompt, image, seed, ratio, duration, and audio setting.
- Synthorai serves it via the asynchronous /v1/videos job API: create a task, poll its status URL, or hold the call open with Prefer: wait.
FAQ
Is the Seedance 1.5 Pro 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 Seedance 1.5 Pro against your real workload before adding a payment method.
What is Seedance 1.5 Pro best at?
Audio or silent output at separate rates; 480p to 1080p, 4-12 seconds; only Seedance with draft mode. See the About section for the full picture from the vendor's own release notes.
How much does Seedance 1.5 Pro cost?
Seedance 1.5 Pro costs $2.4 per million video tokens on Synthorai (video tokens ≈ width × height × 24fps × seconds ÷ 1024). Only successful generations are billed: pay-as-you-go, no platform markup, no subscription.
How do I generate videos with the Seedance 1.5 Pro API?
POST to /v1/videos on Synthorai with model="seedance-1-5-pro-251215" to create an asynchronous job, then poll the task (or hold the request open with a Prefer: wait header) until the video URL is ready. No vendor SDK is needed.
How do I get access to Seedance 1.5 Pro?
Point your existing OpenAI SDK at base_url="https://synthorai.io/v1", set model="seedance-1-5-pro-251215", and you're done. One API key covers every model on the gateway.
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Every value on this page is transcribed from the vendor's own documentation, linked above, and carries the date it was checked. Prices are compared across the catalogue; specification values that vendors define differently are shown with the difference stated rather than charted. Nothing here is measured by us, and nothing is scored.