PopNowAPI
Get API key

Seedance 2.5 Plus API

by ByteDance

Seedance 2.5 image-to-video, 4 to 30 seconds with sound

bytedance/seedance-2.5-plus/image-to-video
  • Up to 4K
  • 4–30s clips
  • Sound included
  • Start and end frames
  • Image to Video
  • Extend Video

Call it with the model name bytedance/seedance-2.5-plus/image-to-video on POST /jobs/createTask, from $1.08.

Model namebytedance/seedance-2.5-plus/image-to-video
EndpointPOST https://api.popnow.ai/api/v1/jobs/createTask
# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "bytedance/seedance-2.5-plus/image-to-video",
  "input": {
    "image_url": "https://media.popnow.ai/influencer/examples/marco.webp",
    "resolution": "720p",
    "duration_seconds": 5,
    "generate_audio": true
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

The input is built from the schema below, so it passes validation as written. Change the prompt and links to your own.

Price

OptionUSD per second
resolution 480p$0.216
resolution 720p$0.432
resolution 1080p$1.08
resolution 4K$2.16

Billed in USD · Every option and its price: GET /models/bytedance/seedance-2.5-plus/image-to-video

Limits

Clip length
4–30 s
Resolutions
480p · 720p · 1080p · 4K
Prompt length (characters)
5,000

Parameters

These fields come from the same schema we check every request against. Fields that are not listed are rejected.

  • image_urlstringRequired

    The picture to start from.

    Range
    image/jpeg, image/png, image/webp, image/gif
  • promptstringOptional

    Describe the scene, action, camera movement, and mood for the video.

    Range
    0 – 5000 chars
  • last_image_urlstringOptional

    Optional final frame, so the clip ends exactly where you want.

    Range
    image/jpeg, image/png, image/webp, image/gif
  • resolutionstringOptionalChanges the price

    Output size. Bigger sizes look sharper and cost more.

    Default
    "720p"
    Allowed values
    "480p""720p""1080p""4k"
  • duration_secondsintegerOptionalChanges the price

    How long the clip runs. You pay per second.

    Default
    5
    Range
    4 – 30
  • generate_audiobooleanOptionalChanges the price

    Adds sound made to match the picture: voices, ambience and effects.

    Default
    true
  • seedintegerOptional

    Reuse the same number to get a repeatable result.

    Range
    0 – 2147483647
Raw JSON Schema
{
  "additionalProperties": false,
  "properties": {
    "duration_seconds": {
      "default": 5,
      "description": "The duration of the generated video in seconds (4-30s).",
      "maximum": 30,
      "minimum": 4,
      "type": "integer"
    },
    "generate_audio": {
      "default": true,
      "description": "Whether to generate native audio synchronized with the output video. Defaults to true.",
      "type": "boolean"
    },
    "image_url": {
      "contentMediaType": [
        "image/jpeg",
        "image/png",
        "image/webp",
        "image/gif"
      ],
      "description": "Start image URL to guide the video generation.",
      "type": "string"
    },
    "last_image_url": {
      "contentMediaType": [
        "image/jpeg",
        "image/png",
        "image/webp",
        "image/gif"
      ],
      "description": "Last frame image URL for video continuation.",
      "type": "string"
    },
    "prompt": {
      "description": "Describe the scene, action, camera movement, and mood for the video.",
      "maxLength": 5000,
      "type": "string"
    },
    "resolution": {
      "default": "720p",
      "description": "The output video resolution.",
      "enum": [
        "480p",
        "720p",
        "1080p",
        "4k"
      ],
      "type": "string"
    },
    "seed": {
      "description": "Random seed. Omit to let the model pick one.",
      "maximum": 2147483647,
      "minimum": 0,
      "type": "integer"
    }
  },
  "required": [
    "image_url"
  ],
  "type": "object"
}

Responses, polling and callbacks

Every model works the same way: create a task, then poll it or wait for a callback.

Price it first

cURL
curl -X POST https://api.popnow.ai/api/v1/jobs/quote \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "bytedance/seedance-2.5-plus/image-to-video",
  "input": {
    "image_url": "https://media.popnow.ai/influencer/examples/marco.webp",
    "resolution": "720p",
    "duration_seconds": 5,
    "generate_audio": true
  }
}'

Send the same request body to POST /jobs/quote to see the estimated and maximum USD charge before running. A quote does not run the task or charge your balance.

Accepted

HTTP
HTTP/1.1 202 Accepted

{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_01k3m8x9q2z4v7n5p6r8s0t1w3",
    "state": "queued"
  },
  "request_id": "req_example_create"
}

HTTP 202 means accepted: the maximum USD amount is held until settlement. When a task is accepted, we reserve the maximum quoted amount from your API balance. On completion, we charge for actual usage, never more than the hold, and release the remainder. If the task fails, the hold is released.

Check status

cURL
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Poll every few seconds with backoff and stop once state is succeeded, failed, canceled or expired.

Finished task

JSON
{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_01k3m8x9q2z4v7n5p6r8s0t1w3",
    "model": "bytedance/seedance-2.5-plus/image-to-video",
    "state": "succeeded",
    "output": {
      "assets": [
        {
          "url": "https://cdn.popnow.ai/tasks/task_01k3m8x9q2z4v7n5p6r8s0t1w3/output.mp4?signature=FROM_RESPONSE",
          "expiresAt": "2026-10-17T12:20:00Z",
          "mime": "video/mp4",
          "width": 1280,
          "height": 720,
          "durationSeconds": 5
        }
      ]
    },
    "settled": true
  },
  "request_id": "req_example_record"
}

Download from url before expiresAt. Need a fresh link later? Ask POST /common/download-url.

Verify a callback

Node.js
import { createHash, createHmac, timingSafeEqual } from "node:crypto";
import express from "express";

const app = express();
// express.raw keeps the exact bytes that were signed; express.json would not match.
app.post("/hooks/popnow", express.raw({ type: "application/json" }), (req, res) => {
  const timestamp = req.header("X-Webhook-Timestamp");
  const signature = req.header("X-Webhook-Signature") ?? "";
  const body = JSON.parse(req.body.toString("utf8"));
  const taskId = body.data?.taskId ?? body.task_id;
  const digest = createHash("sha256").update(req.body).digest("hex");
  const expected = createHmac("sha256", process.env.POPNOW_WEBHOOK_SECRET)
    .update(`${taskId}.${timestamp}.${digest}`)
    .digest("base64");
  const ok = expected.length === signature.length && timingSafeEqual(Buffer.from(expected), Buffer.from(signature));
  // Check the signature first, then reject anything older than five minutes.
  if (!ok || Math.abs(Date.now() / 1000 - Number(timestamp)) > 300) return res.status(401).end();
  res.status(200).end(); // answer fast, then fetch the task and store its files
});

With callBackUrl set, we post the finished task to you. Check the signature against the raw body before you trust it.

Send a local file

cURL
curl -X POST https://api.popnow.ai/api/v1/common/upload-url \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"contentType": "image/png", "bytes": 482113}'

# PUT the file bytes to data.uploadUrl with every header in data.headers, then commit it:
curl -X POST https://api.popnow.ai/api/v1/files/$FILE_ID/commit \
  -H "Authorization: Bearer $POPNOW_API_KEY"
# The commit returns a popnow://f/... reference. Put it in any image, video or
# audio field of the task input instead of a public https URL.

Public https links work as they are. Local files go through upload-url and commit first.

About Seedance 2.5 Plus

Seedance 2.5 image-to-video, 4 to 30 seconds with sound.

Call it with the model name bytedance/seedance-2.5-plus/image-to-video on POST /jobs/createTask, from $1.08.

Request parameters

ParameterRequiredDescription
duration_secondsNoHow long the clip runs. You pay per second. ≥ 4 · ≤ 30 · Default: 5
generate_audioNoAdds sound made to match the picture: voices, ambience and effects. Default: true
image_urlYesThe picture to start from.
last_image_urlNoOptional final frame, so the clip ends exactly where you want.
promptNoDescribe the scene, action, camera movement, and mood for the video.
resolutionNoOutput size. Bigger sizes look sharper and cost more. 480p · 720p · 1080p · 4k · Default: 720p
seedNoReuse the same number to get a repeatable result. ≥ 0 · ≤ 2147483647

Pricing

Prices are in USD. The API uses a separate USD balance. Website credits cannot be used or transferred to it, and API funds cannot be transferred to website credits. When a task is accepted, we reserve the maximum quoted amount from your API balance. On completion, we charge for actual usage, never more than the hold, and release the remainder. If the task fails, the hold is released.

OptionUSD per second
resolution 480p$0.216
resolution 720p$0.432
resolution 1080p$1.08
resolution 4K$2.16

Send the same request body to POST /jobs/quote to see the estimated and maximum USD charge before running. A quote does not run the task or charge your balance.

API quick start

Call the Seedance 2.5 Plus API in three steps

  1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow-. API calls use your separate USD balance.
  2. Send the request. POST /jobs/createTask with model bytedance/seedance-2.5-plus/image-to-video and an input object that follows the parameter table. The response returns a task ID straight away.
  3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.
# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "bytedance/seedance-2.5-plus/image-to-video",
  "input": {
    "image_url": "https://media.popnow.ai/influencer/examples/marco.webp",
    "resolution": "720p",
    "duration_seconds": 5,
    "generate_audio": true
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

Seedance 2.5 Plus API questions

How much does the Seedance 2.5 Plus API cost?

Seedance 2.5 Plus starts at $1.08 for a 5-second clip with Image to Video, its cheapest task. Prices by option: 480p $0.216 per second, 720p $0.432 per second, 1080p $1.08 per second, 4K $2.16 per second. The API uses a separate USD balance. Website credits cannot be used or transferred to it, and API funds cannot be transferred to website credits. When a task is accepted, we reserve the maximum quoted amount from your API balance. On completion, we charge for actual usage, never more than the hold, and release the remainder. If the task fails, the hold is released.

What is the model name for Seedance 2.5 Plus in the API?

Put bytedance/seedance-2.5-plus/image-to-video for Image to Video; bytedance/seedance-2.5-plus/video-extend for Extend Video in the model field of POST /jobs/createTask.

What are the limits of the Seedance 2.5 Plus API?

Clip length: 4–30 s; Resolutions: 480p · 720p · 1080p · 4K; Prompt length (characters): 5,000. Requests outside these limits are rejected before anything is charged.

More about Seedance 2.5 Plus