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by ByteDance

Exact text in 2K and 4K images, with edits from up to 14 references

bytedance/seedream-4.5/text-to-image
  • Up to 4K
  • Up to 14 reference images
  • 8 aspect ratios
  • Create Image
  • Edit Image

About Seedream 4.5

Seedream 4.5 can power a marketing artwork editor that combines scene creation with multi-reference image production. Its prompt can include exact quoted wording, and both available resolution tiers share a rate. The botanical perfume ad and arctic explorer examples demonstrate creation outputs; Product new scene gives a revision fixture. Keep written copy as editable project data so users can inspect the generated lettering before approving an asset.

Call it with the model name bytedance/seedream-4.5/text-to-image on POST /jobs/createTask, from $0.04.

Introduction

Seedream 4.5 Text to image draws one image from a written prompt on Seedream 4.5, ByteDance's image model, at 2K or 4K in eight aspect ratios. For changing or combining pictures, use Seedream 4.5 Image Editing.

Choose a model by what you need

What you needModel
a new image from words aloneSeedream 4.5 Text to image (you are here)
edit, restyle or combine up to 14 picturesSeedream 4.5 Image Editing

Key features

Text that comes out as quoted

A film poster with its title and bottom line and a perfume bottle with its engraved name were spelled correctly in our tests. ByteDance says text rendering is better in 4.5. We only tried English.

Eight ratios

From 21:9 to 9:16. At 2k, 16:9 is 2848 x 1600, 3:2 is 2496 x 1664 and 1:1 is 2048 x 2048.

Request parameters

ParameterRequiredDescription
promptYesDescribe what you want to make.
resolutionNoChoose an available output size. 2k · 4k · Default: 2k
aspect_ratioNoThe shape of the frame: wide, square or tall. 1:1 · 4:3 · 3:4 · 16:9 · 9:16 · 3:2 · 2:3 · 21:9 · Default: 1:1

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 image
Standard$0.04

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

Posters and ads

A title, a tagline and a product name in one picture. Quote each string and place it.

Cinematic frames

Wide 21:9 and 16:9 stills with a lens, a palette and a light source named.

Group scenes and portraits

Four friends at a pool, a couple dancing close, a boxer in an old gym: several people with their own outfits in one frame.

Prompt guide & pro tips

Quote the text, then place it

Write "NOIR VELOURS" in quotes, then say where it goes and how it looks: engraved in gold on the bottle. Keep the strings short enough to read at the size you choose.

Name the light and the lens

A single beam of warm gold light from the left, 50mm, shallow depth of field, film grain. These details shape the result more than adjectives do.

Give each person their own sentence

For group scenes, describe each person by outfit and action in turn, as in the four-friends pool prompt.

Plan for different results

There is no seed, so the same prompt returns a different image each time. Save the ones you like and keep the prompt with them.

Describe what you want

There is no negative prompt. Say what is in the frame, not what to leave out.

API quick start

Call the Seedream 4.5 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-4.5/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-4.5/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "1:1",
    "resolution": "2k"
  }
}'

# 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.

What to build with the Seedream 4.5 API

  • Create a packaging or campaign draft tool that compiles subject, layout, lighting and quoted text into a scene prompt. Save the literal wording separately so proofreading does not require recovering it from a finished image.
  • Provide a reference composition stage that assigns a contribution to each uploaded picture. Keep that contribution list with the request, helping reviewers distinguish source product details from the proposed environment.

Seedream 4.5 parameter notes

  • prompt is nonempty and has a tighter bound than many image models. Validate after inserting marketing copy and application templates, because several individually valid form fields can exceed the combined request limit.
  • resolution accepts 2k or 4k. Both have the same rate, so describe this as a size choice rather than an automatically more expensive quality upgrade. aspect_ratio is a separate fixed enum with square as its default on both routes.
  • Editing requires image_urls, a nonempty array of authorized references within the stated maximum. There is no auto aspect ratio, seed or negative_prompt field. Do not forward hidden controls left over from another renderer in a shared editing form.

How Seedream 4.5 API pricing adds up

Generation and editing are metered per image. The listed resolution tiers share the rate, and the catalog does not define an extra charge for each reference in this model. Quote the final payload and confirm its current USD maximum. Use completed costUsd for settlement instead of deriving cost from megapixels or reference count.

  • Create Image: $0.04 per run, $4.00 for 100 runs

Async jobs, webhooks and rate limits

Every Seedream 4.5 request is asynchronous: createTask returns a taskId straight away, and the result arrives when the job finishes. Poll GET /jobs/recordInfo every few seconds, or pass a public https callBackUrl and verify the X-Webhook-Signature header (HMAC-SHA256 over taskId, timestamp and the body hash) before trusting the payload. Each account gets 1,000 write requests per 10 seconds; a 429 carries Retry-After. Send an Idempotency-Key with createTask so a retried request for bytedance/seedream-4.5/text-to-image never runs or bills twice.

Common Seedream 4.5 API errors

errorCodeWhat it usually means and how to fix it
invalid_requestCheck the assembled prompt against its bound and use only supported size and ratio values. Remove seed and auto ratio settings copied from other models.
invalid_assetEnsure editing references resolve to accessible image files. Retain their intended contributions in the brief when repairing a missing source.
content_rejectedAllow the author to revise the artwork brief or references using the returned explanation. Do not automatically generate repeated versions of an unchanged refused request.

Seedream 4.5 price on other platforms

OptionsPopNowfalKieReplicate
Seedream 4.5Guaranteed$0.0400/ image$0.0400/ image$0.0325/ image$0.0400/ image

Each platform's public API list price for the same model and settings, checked Nov 5, 2026.

Seedream 4.5 API questions

How much does the Seedream 4.5 API cost?

Seedream 4.5 starts at $0.04 per image with Create Image, its cheapest task. The API uses a separate USD balance. 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 Seedream 4.5 in the API?

Put bytedance/seedream-4.5/text-to-image for Create Image; bytedance/seedream-4.5/edit for Edit Image in the model field of POST /jobs/createTask.

Does the larger image tier imply a higher unit rate?

The catalog lists the available size tiers at the same rate. Keep the selection in the request and let the live quote supply the actual USD amount.

How should a campaign editor handle completion?

Store taskId under the campaign revision, poll recordInfo or verify a task callback, then attach the delivered assets. Keep the submitted copy available for a final visual proofreading pass.

Can my edit keep the source shape automatically?

This endpoint has explicit aspect ratios and defaults to square. Choose a supported ratio intentionally; do not send the auto value used by some other image editors.

What are the limits of the Seedream 4.5 API?

Resolutions: 2K · 4K; Aspect ratios: 1:1 · 4:3 · 3:4 · 16:9 · 9:16 · 3:2 +2; Prompt length (characters): 3,000. Requests outside these limits are rejected before anything is charged.

Can I try Seedream 4.5 without writing code?

Run Seedream 4.5 in the Playground with your API USD balance, without an API key. Each run appears in your developer history with its matching code.

All Seedream models

Seedream 5.0 Pro adds a thinking pass and layer splitting, with up to ten editing references. Seedream 4.5 accepts fourteen and includes a 4K output tier.

More about Seedream 4.5