Seedream 5.5 API

About Seedream 5.5

Seedream 5.5 is ByteDance's newest Seedream image model. It makes images from a prompt, edits with up to ten pictures, and splits a finished image into a base and transparent layers. Sizes run from 1K to 4K in eight aspect ratios, and PNG output can have a transparent background.

Call it with the model name bytedance/seedream-5.5/text-to-image on POST /jobs/createTask, from $0.0195.

Introduction

Seedream 5.5 from ByteDance turns a written scene into an image. It suits layouts with small text in several languages, photographs and product cut-outs.

Key features

• Small multilingual text: a 2k menu test reproduced an English title, a Japanese subtitle, four menu lines and a footnote exactly as written.
• Transparent PNGs: set output_format to png and background to transparent for a real alpha channel. A JPEG always stays opaque.
• Size choices: resolution takes 1k, 1.5k, 2k or 4k, and aspect_ratio takes eight values. The default is 1:1 at 2k.

Request parameters

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.

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.

Use cases

• Menus and posters: lay out a heading, a subtitle in another language, a list and a footnote.
• Product cut-outs: make a transparent PNG of a product to use as a separate graphic.
• Editorial photographs: describe a candid scene with its setting and its light.

Prompt guide & pro tips

• Spell out the text: give every line exactly as it should read, and say which one is the title, the subtitle or the footnote.
• Use the settings for transparency: writing "cut-out" in the prompt doesn't replace background: transparent.
• Stay within the limit: a prompt can run to 5,000 characters, and ByteDance recommends 600 English words or fewer.

API quick start

Call the Seedream 5.5 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/seedream-5.5/text-to-image 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/seedream-5.5/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "1:1",
    "resolution": "2k",
    "output_format": "png",
    "background": "auto"
  }
}'

# 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.

Seedream 5.5 API questions

All Seedream models

Seedream 5.0 Pro stops at 2K, but its edits can follow the shape of your picture. Choose it when you want that done for you.

• Seedream 5.0 Pro APIHigh-detail images and edits from up to ten referencesFrom $0.036 per image
• Seedream 5.5 API4K images with small multilingual text, transparent PNGs and layer splitsFrom $0.0195 per image
• Seedream 5.0 Flash APIQuick Seedream images, edits and layer splits up to 2KFrom $0.026 per image
• Seedream 5.0 Lite APIFixed-size 2K frames that keep a series consistentFrom $0.0345 per image
• Seedream 4.5 APIExact text in 2K and 4K images, with edits from up to 14 referencesFrom $0.04 per image
• Seedream 4.0 APIExact sizes up to 4096×2304 and ten-reference editsFrom $0.0318 per image

Other image APIs

• GPT Image 2.5 Sunburst APIOpenAI's quality-first model, up to 4K with clean textFrom $0.00182 per image
• FLUX.2 Max APITop-tier FLUX: photoreal light and exact brand colorsFrom $0.07 per image
• Qwen Image 2.1 Pro APIUp to six detailed 2K images from one promptFrom $0.036 per image
• GPT Image 2.6 Sunburst APIOpenAI's precision tier for detail that holds across repeated edits, up to 4KFrom $0.02232 per image

More about Seedream 5.5

Try it

Seedream 5.5 AI Image Generator onlineCreate images with Seedream 5.5 in PopNow

Endpoints

Seedream 5.5 · Edit ImageSeedream 5.5 · Layer Splitter

Docs

Seedream 5.5 model ID and input schema in the API docsPopNow API quickstart: send your first requestImage generation guide for the PopNow APIWebhooks: get Seedream 5.5 results without polling