Seedream 4.5 API

Seedream 4.5 is ByteDance/Seed’s multimodal image model (text→image + image editing) that focuses on production-grade image fidelity, stronger prompt adherence, and much-improved editing consistency (subject preservation, text/typography rendering, and facial realism).

What is Seedream 4.5?

Seedream 4.5(doubao-seedream-4-5-251128) is the build identifier used on Volcano Engine / Doubao model listings for the Seedream 4.5 family. It exposes text→image, image→image (editing), multi-reference fusion and sequential / multi-image generation interfaces tailored for advertising, e-commerce, film/TV previsualization, creative asset pipelines and other production workflows.

Main features of Seedream 4.5

• High-fidelity generation up to 4K textures (improved over prior 4.0 outputs).
• Robust image editing / subject preservation — edits retain lighting, color tone and fine detail for consistent edits across iterations.
• Better small-text and facial/detail rendering compared with Seedream 4.0 (reduced smearing of small text, clearer facial features while retaining naturalness).
• Multi-image fusion and sequential (set) generation for consistent multi-panel/storyboard outputs (keep characters/props/styles coherent across frames).
• Multiple generation modes: text-to-image, image-to-image (single and multi-reference), set/sequence generation, and streaming outputs for incremental image delivery.

Technical capabilities & specifications

Capabilities

• Text-to-image generation (single image or sets).
• Image editing (inpainting, outfit/hair/outdoor/background replacement) using a supplied reference image.
• Multi-reference fusion (2–10 references) and multi-image output modes for consistent series generation.
• Streaming and asynchronous task modes for long or high-resolution renders.

Typical API / request parameters

• model: "doubao-seedream-4-5-251128" (or service wrapper alias).
• prompt: natural-language prompt (supports long prompts and references).
• image / images: one or more reference image URLs for editing / fusion.
• size (examples: 1K, 2K, 4K); resolution affects latency and cost.
• response_format: typically url (link to generated image) or base64 depending on provider.

For the group image parameter “sequential_image_generation_options,” the relay system is compatible by using the input parameter “n”; for example: “n”: 1. The number of reference images provided plus the number of final generated images must be ≤ 15.

Limitations & known failure modes

• Hallucinated text can still occur when generating small or dense typography (improved but not perfect).
• Over-stylization / “beautification” bias — portrait outputs may trend toward idealized looks (model-specific aesthetic priors), which can be undesirable for some photorealistic use cases.
• Safety / content policy — as with any powerful image generator: the model must be used with content moderation pipelines to block illicit/NSFW/hate content and to respect copyright and likeness rights. Vendor docs and platform integrations include audit and safety tooling recommendations.

How Seedream 4.5compares to Nano Banana

• Seedream 4.5 vs Seedream 4.0: improved editing consistency, better face & text rendering, and stronger multi-image coherence.
• Seedream 4.5 vs Nano Banana / Google image editing stack: Seedream 4.5 as comparable or superior on some editing/typography tasks; Nano Banana remains strong for ultra-low latency mobile workflows and certain types of stylized outputs.

Representative production use cases

• E-commerce: automated product photos, background swaps, label/logo consistent renders at 4K for catalogs.
• Advertising & editorial: photorealistic compositions and multi-frame storyboards where subject continuity matters (actor/character consistency).
• Game/art asset prototyping: fast, high-fidelity concept images and character pose series.
• Studio retouch & portrait pipelines: fine retouching and beautification that preserves identity and lighting cues.
• Brand design / packaging: crisp text and typography on generated mockups (still requires legal/brand checks).

How to access and use Seedream 4.0 API

Seedream 4.0 API Pricing in CometAPI: 0.04$

Required Steps

• Log in to cometapi.com. If you are not our user yet, please register first
• Get the access credential API key of the interface. Click “Add Token” at the API token in the personal center, get the token key: sk-xxxxx and submit.
• Get the url of this site: https://api.cometapi.com/

Use Method

1. Select the “doubao-seedream-4-5-251128” endpoint to send the API request and set the request body. The request method and request body are obtained from our website API doc. Our website also provides Apifox test for your convenience.
2. Replace <YOUR_API_KEY> with your actual CometAPI key from your account.
3. Insert your question or request into the content field—this is what the model will respond to.
4. . Process the API response to get the generated answer.

CometAPI provides a fully compatible REST API—for seamless migration. Key details to seedream image  API doc:

• Endpoint: https://api.cometapi.com/v1/images/generations
• Model Parameter: doubao-seedream-4-5-251128
• Authentication:  Bearer YOUR_CometAPI_API_KEY 
• Content-Type: application/json .

curl 
--location 
--request POST 'https://api.cometapi.com/v1/images/generations' \ 
--header 'Authorization: Bearer {{api-key}}' \ --header 'Content-Type: application/json' \ 
--data-raw 
'{ 
"model": "doubao-seedream-4-5-251128", 
"prompt": "Generate a close-up image of a dog lying on lush grass.", 
    "response_format": "url",
    "size": "2K",
    "stream": false,
    "watermark": true }'

See also Gemini 3 Pro Image( Nano Banana Pro)