Seedance 2.5

ByteDance · ~4 min

from $0.075per second

ByteDance's newest video model: clips up to 30 seconds with sound, from a description, frames or references.

Seedance 2.5 is the newest ByteDance video model. It films 4 to 30 second clips in 480p, 720p and 1080p with sound: from a description, from the first and last frame, from references (up to 30 photos, 10 clips and 10 audio tracks), and it edits and continues your video.

Pick «Auto» length and the model decides: the price of 30 seconds is held and the rest comes back right after the video is ready.

One model, seedance-2.5 · ~4 min. The result follows the input fields (prompt, frames, references, video_mode, duration) — there are no separate «animate / edit» endpoints.

Features

prompt — up to 30000 characters
duration: "auto" / -1 — model picks length (on the site: auto (-1))
video_mode: auto · reference · edit · extend
watermark — "AI generated" mark
output_format: mp4 (default) or mov
return_last_frame — last-frame URL for chaining
generate_audio — audio in the clip
nsfw_check — check before charge
web_search / tools: [{"type":"web_search"}] — fresh web grounding

Price

Resolution	Price per second	With your video, per second
480p	$0.125	$0.075
720p	$0.281	$0.169
1080p	$0.501	$0.299

Price = per-second price × clip length, rounded up to $0.001. Charged when the task is created and fully refunded if it fails.
With your video, the seconds of the source clip are added to the seconds of the result.
On the site — the auto (-1) tick next to the duration (not a list item). In the API: duration: "auto" or -1 lets the model choose the length, up to 30 s. On creation the price of 30 s is charged (plus your video seconds, if any). When the video is ready the price is recalculated from the real length and the difference goes straight back to your balance (history: «Refund for unused video seconds»). The final price is costUsd in recordInfo, the length is duration in resultJson. With video_mode: "edit" the result is as long as your clip.

Media limits

Type	Limits
Images	up to 30; JPG / PNG / WebP (also BMP / TIFF / GIF / HEIC via public https; or `asset://…` if you already have an id); upload via files/upload — up to 30 MB per file
Videos	up to 10; total ≤ 30 s (each clip 2…30 s); MP4 / MOV → MP4 on the server; upload ≤ 200 MB
Audio	up to 10; total ≤ 30 s; MP3 / WAV; upload ≤ 200 MB; audio-only (no photo/video) is allowed

Photos — public https or upload; video and audio — files/upload only.

Task types and constraints

`video_mode`	What you need	Notes
`auto`	prompt; media optional	default; the model picks reference / edit / extend
`reference`	photo / video / audio references	character, place, motion, style
`edit`	`video_urls`	length and aspect ratio follow your clip; clip ≥ 4 s
`extend`	`video_urls`	continue the clip

Field omni_reference_task_type is an alias of video_mode (accepted by the API).

Tip: with video_urls the site preselects aspect_ratio: adaptive and duration: auto / -1 (auto (-1) tick) — the model is picky about tiny duration mismatches. You can still set other values manually.

480p draft → 1080p final

Create a task with draft: true (resolution forced to 480p).
Wait for success, then POST with draft_task_id = your taskId (no prompt or media). Final is 1080p; reference-video seconds are not billed again.
Only output_format, watermark, return_last_frame may change. Drafts last 7 days. draft and draft_task_id are mutually exclusive.

On the site: «480p draft» tick; on recent works the 1080p button.

Parameters (field `input`)

Parameter	Description	Values (default in bold)
`prompt`	What happens in the clip: scene, motion, camera, light, style	text, up to 30000 chars
`first_frame_url`	First frame: a photo link (https); the video starts from it	`"https://…"`
`last_frame_url`	Last frame (optional, only together with the first one)	`"https://…"`
`image_urls`	Reference photos (https)	`["https://…"]`, up to 30
`video_urls`	Your videos (MP4): upload them via files/upload first and pass the returned links	`["https://…"]`, up to 10
`audio_urls`	Audio (MP3): upload via files/upload first	`["https://…"]`, up to 10
`video_mode`	Task type for your video: `auto` (default) — the model works it out from the description, `reference` — reference, `edit` — edit (length and aspect ratio follow your video), `extend` — extend. Omitted = `auto`	`auto` (the model works it out) · `reference` (reference) · `edit` (edit) · `extend` (extend)
`resolution`	Video resolution	`480p` (standard) · `720p` (high (HD)) · `1080p` (Full HD)
`aspect_ratio`	Aspect ratio	`adaptive` (matches your upload) · `16:9` (landscape) · `9:16` (portrait) · `1:1` (square) · `4:3` (traditional) · `3:4` (vertical traditional) · `21:9` (ultra-wide)
`duration`	Video duration in seconds	4 to 30 s, or `auto` / `-1` (the model picks the length) (default `5`)
`generate_audio`	Video with sound	`true` `false` (default `true`)
`return_last_frame`	Return the last-frame image URL (for continuing the clip)	`true` `false` (default `false`)
`output_format`	Result container: `mp4` (default) or `mov`	`mp4` `mov`
`draft`	Черновик 480p	`true` `false` (default `false`)
`web_search`	Web search: fresh information from the internet (real places, events, products)	`true` `false` (default `false`)
`watermark`	"AI generated" watermark on the video	`true` `false` (default `false`)
`nsfw_check`	Content check: the description and photos are checked first; if not allowed, no task is created and nothing is charged	`true` `false` (default `false`)
`seed`	Variant number: the same number with the same prompt gives a similar result; empty or -1 = random	-1…4294967295
`trim_video_to`	Trim each of your clips to N seconds: the beginning stays. Shorter clips are not changed	whole number, 2 to 30
`trim_to_duration`	Trim each of your clips to the chosen `duration`: the beginning stays. With `duration: "auto"` or `video_mode: "edit"` — to the model limit	`true` `false` (default `false`)
`auto_trim`	If your clips together are longer than 30 s, trim them instead of returning an error (the longest first)	`true` `false` (default `false`)

Examples

Prompt only

curl -X POST https://mixmedia.tech/api/v1/jobs/createTask \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"seedance-2.5","input":{"prompt":"A drone flies over an autumn forest at sunrise, fog, cinematic","resolution":"720p","aspect_ratio":"adaptive","duration":"5"}}'

import os, requests

r = requests.post(
    "https://mixmedia.tech/api/v1/jobs/createTask",
    headers={"Authorization": f"Bearer {os.environ['API_KEY']}"},
    json={
      "model": "seedance-2.5",
      "input": {
        "prompt": "A drone flies over an autumn forest at sunrise, fog, cinematic",
        "resolution": "720p",
        "aspect_ratio": "adaptive",
        "duration": "5"
      }
    },
)
print(r.json())  # {"code": 200, "data": {"taskId": "..."}}

const r = await fetch("https://mixmedia.tech/api/v1/jobs/createTask", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.API_KEY}`, "Content-Type": "application/json" },
  body: JSON.stringify({
    "model": "seedance-2.5",
    "input": {
      "prompt": "A drone flies over an autumn forest at sunrise, fog, cinematic",
      "resolution": "720p",
      "aspect_ratio": "adaptive",
      "duration": "5"
    }
  }),
});
console.log(await r.json()); // { code: 200, data: { taskId: "..." } }

With a first frame

curl -X POST https://mixmedia.tech/api/v1/jobs/createTask \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"seedance-2.5","input":{"prompt":"The character slowly turns to the camera, the wind moves the hair","first_frame_url":"https://mixmedia.tech/static/img/previews/gpt-t2i.jpg","resolution":"720p","duration":"5"}}'

import os, requests

r = requests.post(
    "https://mixmedia.tech/api/v1/jobs/createTask",
    headers={"Authorization": f"Bearer {os.environ['API_KEY']}"},
    json={
      "model": "seedance-2.5",
      "input": {
        "prompt": "The character slowly turns to the camera, the wind moves the hair",
        "first_frame_url": "https://mixmedia.tech/static/img/previews/gpt-t2i.jpg",
        "resolution": "720p",
        "duration": "5"
      }
    },
)
print(r.json())  # {"code": 200, "data": {"taskId": "..."}}

const r = await fetch("https://mixmedia.tech/api/v1/jobs/createTask", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.API_KEY}`, "Content-Type": "application/json" },
  body: JSON.stringify({
    "model": "seedance-2.5",
    "input": {
      "prompt": "The character slowly turns to the camera, the wind moves the hair",
      "first_frame_url": "https://mixmedia.tech/static/img/previews/gpt-t2i.jpg",
      "resolution": "720p",
      "duration": "5"
    }
  }),
});
console.log(await r.json()); // { code: 200, data: { taskId: "..." } }

With references

curl -X POST https://mixmedia.tech/api/v1/jobs/createTask \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"seedance-2.5","input":{"prompt":"A drone flies over an autumn forest at sunrise, fog, cinematic","image_urls":["https://mixmedia.tech/static/img/previews/gpt-t2i.jpg"],"resolution":"720p","aspect_ratio":"adaptive","duration":"5"}}'

import os, requests

r = requests.post(
    "https://mixmedia.tech/api/v1/jobs/createTask",
    headers={"Authorization": f"Bearer {os.environ['API_KEY']}"},
    json={
      "model": "seedance-2.5",
      "input": {
        "prompt": "A drone flies over an autumn forest at sunrise, fog, cinematic",
        "image_urls": [
          "https://mixmedia.tech/static/img/previews/gpt-t2i.jpg"
        ],
        "resolution": "720p",
        "aspect_ratio": "adaptive",
        "duration": "5"
      }
    },
)
print(r.json())  # {"code": 200, "data": {"taskId": "..."}}

const r = await fetch("https://mixmedia.tech/api/v1/jobs/createTask", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.API_KEY}`, "Content-Type": "application/json" },
  body: JSON.stringify({
    "model": "seedance-2.5",
    "input": {
      "prompt": "A drone flies over an autumn forest at sunrise, fog, cinematic",
      "image_urls": [
        "https://mixmedia.tech/static/img/previews/gpt-t2i.jpg"
      ],
      "resolution": "720p",
      "aspect_ratio": "adaptive",
      "duration": "5"
    }
  }),
});
console.log(await r.json()); // { code: 200, data: { taskId: "..." } }

With your video

curl -X POST https://mixmedia.tech/api/v1/jobs/createTask \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"seedance-2.5","input":{"prompt":"Make the clip anime style, keep everything else","video_urls":["https://mixmedia.tech/files/<id>.mp4"],"video_mode":"edit","resolution":"720p","duration":"5"}}'

import os, requests

r = requests.post(
    "https://mixmedia.tech/api/v1/jobs/createTask",
    headers={"Authorization": f"Bearer {os.environ['API_KEY']}"},
    json={
      "model": "seedance-2.5",
      "input": {
        "prompt": "Make the clip anime style, keep everything else",
        "video_urls": [
          "https://mixmedia.tech/files/<id>.mp4"
        ],
        "video_mode": "edit",
        "resolution": "720p",
        "duration": "5"
      }
    },
)
print(r.json())  # {"code": 200, "data": {"taskId": "..."}}

const r = await fetch("https://mixmedia.tech/api/v1/jobs/createTask", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.API_KEY}`, "Content-Type": "application/json" },
  body: JSON.stringify({
    "model": "seedance-2.5",
    "input": {
      "prompt": "Make the clip anime style, keep everything else",
      "video_urls": [
        "https://mixmedia.tech/files/<id>.mp4"
      ],
      "video_mode": "edit",
      "resolution": "720p",
      "duration": "5"
    }
  }),
});
console.log(await r.json()); // { code: 200, data: { taskId: "..." } }

Trim your video

Your clips together: up to 30 s. No need to cut a long clip beforehand:

trim_to_duration: true — trim each clip to the chosen duration;
trim_video_to: N — keep N seconds from the start;
auto_trim: true — if the clips together are over the limit, cut them exactly to it instead of an error.

Trimming is free, and the price uses the trimmed seconds — fewer seconds cost less.

curl -X POST https://mixmedia.tech/api/v1/jobs/createTask \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"seedance-2.5","input":{"prompt":"Make the clip anime style, keep everything else","video_urls":["https://mixmedia.tech/files/<id>.mp4"],"video_mode":"edit","resolution":"720p","duration":"5","trim_to_duration":true,"auto_trim":true}}'

import os, requests

r = requests.post(
    "https://mixmedia.tech/api/v1/jobs/createTask",
    headers={"Authorization": f"Bearer {os.environ['API_KEY']}"},
    json={
      "model": "seedance-2.5",
      "input": {
        "prompt": "Make the clip anime style, keep everything else",
        "video_urls": [
          "https://mixmedia.tech/files/<id>.mp4"
        ],
        "video_mode": "edit",
        "resolution": "720p",
        "duration": "5",
        "trim_to_duration": True,
        "auto_trim": True
      }
    },
)
print(r.json())  # {"code": 200, "data": {"taskId": "..."}}

const r = await fetch("https://mixmedia.tech/api/v1/jobs/createTask", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.API_KEY}`, "Content-Type": "application/json" },
  body: JSON.stringify({
    "model": "seedance-2.5",
    "input": {
      "prompt": "Make the clip anime style, keep everything else",
      "video_urls": [
        "https://mixmedia.tech/files/<id>.mp4"
      ],
      "video_mode": "edit",
      "resolution": "720p",
      "duration": "5",
      "trim_to_duration": true,
      "auto_trim": true
    }
  }),
});
console.log(await r.json()); // { code: 200, data: { taskId: "..." } }

One uploaded file: up to 30 s. Without these options, clips that are too long return a 400 error with a hint.

Create and result

POST /api/v1/jobs/createTask with model and input.
Poll GET /api/v1/jobs/recordInfo?taskId=… every 3–5 s (or a callback).

Successful createTask (HTTP 200)

{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_...",
    "task_id": "task_...",
    "status": "submitted"
  }
}

Completed task (recordInfo)

{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_...",
    "task_id": "task_...",
    "state": "success",
    "status": "completed",
    "costUsd": "0.384",
    "refunded": false,
    "resultJson": {
      "videos": [
        {
          "url": "https://…/out.mp4"
        }
      ],
      "duration": 8
    },
    "lastFrameUrl": "https://…/last.jpg"
  }
}

Aliases: task_id = taskId; status: pending / processing / completed / failed alongside state. Clip URL is in resultJson. size is an alias of aspect_ratio in input.

Photos can be any public https links or uploads via files/upload. Videos and audio — via files/upload only.

Error handling

API responses are JSON {"code", "msg", "data"}; errors also have a string error field (type). On /api/v1/* the HTTP status matches body code.

Example response bodies

400

{
  "code": 400,
  "msg": "input.duration: must be between 4 and 30, or \"auto\" / -1",
  "data": null,
  "error": "invalid_request_error"
}

401

{
  "code": 401,
  "msg": "Authentication failed. Please check your API key",
  "data": null,
  "error": "authentication_error"
}

402

{
  "code": 402,
  "msg": "Insufficient balance. Please top up and try again. Available: $0.01, required: $0.015. Top up at https://ai.aimixmedia.site/cabinet/billing",
  "data": {
    "balance": "0.0100",
    "required": "0.0150",
    "currency": "USD",
    "topUpUrl": "https://mixmedia.tech/cabinet/billing"
  },
  "error": "payment_required"
}

429

{
  "code": 429,
  "msg": "Rate limit exceeded: 10 createTask/upload requests per 10 s per key. Retry after 8s",
  "data": null,
  "error": "rate_limit_error"
}

500

{
  "code": 500,
  "msg": "Internal server error",
  "data": null,
  "error": "server_error"
}

Codes on createTask / upload

code	error	Meaning	What to do
400	`invalid_request_error`	Invalid parameter or body	See `msg`
400	`unsupported_model`	Unknown model	Model list
400	`nsfw_content_detected`	Rejected by content check (`nsfw_check`)	Change the prompt or files
401	`authentication_error`	Missing or invalid key	Check the key
402	`payment_required`	Not enough balance	Top up
403	`permission_error`	No access	Contact support
429	`rate_limit_error`	Too many requests	Wait for `Retry-After`
505	`model_disabled`	Model temporarily disabled	Pick another
500	`server_error`	Our failure	Retry later

Example msg values: Authentication failed. Please check your API key (401); Insufficient balance. Please top up and try again… (402).

Task errors (recordInfo)

If the task was created and then failed: state: "fail" (alias status: "failed"), failCode / failMsg, and error: { code, message, type }. Money is refunded (refunded: true).

failCode	error.type	Meaning
400	`nsfw_content_detected` / `invalid_request_error`	Moderation / safety rules
422	`invalid_request_error`	The model rejected the parameters (length, mode, resolution, file)
501	`server_error`	The model could not generate (`failMsg`)
504	`timeout_error`	Timed out — retry
500 / 503	`server_error`	Service temporarily unavailable

Common refusals for this model

duration out of range, or auto / -1 when auto length is not supported (Seedance 2.5 only)
resolution / aspect_ratio (size) / video_mode not in the list above
video_mode = edit or extend without video_urls; for edit — clip shorter than 4 s
Reference video/audio too long without auto_trim / trim_* → 400
nsfw_check: true — on reject immediate HTTP 400 (nsfw_content_detected); no task, no charge

Rate limits

What	Limit
createTask and upload	20 per 10 s per key
recordInfo / list / balance	100 per 10 s per key

Over the limit — HTTP 429 and Retry-After.

#Features

#Price

#Media limits

#Task types and constraints

#480p draft → 1080p final

#Parameters (field input)

#Examples

#Prompt only

#With a first frame

#With references

#With your video

#Trim your video

#Create and result

#Successful createTask (HTTP 200)

#Completed task (recordInfo)

#Error handling

#Example response bodies

#Codes on createTask / upload

#Task errors (recordInfo)

#Common refusals for this model

#Rate limits