Seedream 4.0 (model identifier bytedance-seedream-4-0-250828) is ByteDance’s newest image-creation foundation model that unifies text→image generation and image editing in a single architecture. The model was announced in early September 2025 and is positioned for high-resolution (up to 4K) generation, multi-reference workflows, and fast inference for production use.
Key features
- Unified generation + editing — one model handles both text-to-image and image-to-image ,Image editing, multi-image editing, group image generation and other creative modes workflows.
- High resolution — supports outputs up to 4K and multiple aspect ratios.
- Multi-reference / group generation — accepts multiple reference images and can create consistent sets of images.
- Faster inference — ByteDance claims substantially faster inference than prior Seedream versions (and improved latency for editing tasks).
- Production ergonomics — features such as text rendering, layout/diagram generation, and prompt-based fine edits (change text, remove objects) are emphasized for real workflows.
Technical details
- Architecture: Seedream 4.0 using a Mixture-of-Experts (MoE) style architecture and other efficiency optimizations to boost throughput and lower per-image cost in production deployments. This change is framed as the principal reason for the model’s claimed ten-fold speed-up vs prior releases.
- Inputs & formats: supports standard image formats (JPEG/PNG), aspect ratios across square/portrait/landscape and both text prompt and one-or-multi-image references as input.
Benchmark performance
ByteDance reports high scores on prompt adherence, alignment (editing fidelity) and aesthetics in its internal benchmark called MagicBench; the company says Seedream 4.0 outperformed earlier Seedream releases and—by their internal ELO comparisons—competes favorably with Google’s Gemini 2.5 Flash Image (“Nano Banana”). Seedream 4.0 is particularly strong at prompt-following and edit fidelity (i.e., it tends to respect user edit instructions and preserve reference content)
Typical use cases
- Marketing & creative production — posters, banners, social graphics where layout, typography, and repeatable edits matter.
- Rapid prototyping for design — multi-reference conditioning allows designers to fuse brand assets with new compositions.
- Batch content generation — product imagery variants, campaign A/B assets, and multi-shot consistent scenes.
- Image editing workflows — precise “change X but keep Y” natural language edits for localization or last-mile creative adjustments.
How to call Seedream 4.0 API from CometAPI
Seedream 4.0
Seedream 4.0| Price | $0.02400 |
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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
- Select the “
bytedance-seedream-4-0-250828 - Replace <YOUR_API_KEY> with your actual CometAPI key from your account.
- Insert your question or request into the content field—this is what the model will respond to.
- . Process the API response to get the generated answer.
CometAPI provides a fully compatible REST API—for seamless migration. Key details to API doc:
- Endpoint:
https://api.cometapi.com/v1/images/generations - Model Parameter:
bytedance-seedream-4-0-250828 - 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": "bytedance-seedream-4-0-250828",
"prompt": "Generate a close-up image of a dog lying on lush grass.",
"image":"https://filesystem.site/cdn/20250414/chxiLc2O45zoLT8BCrQ6WQlTvGDDnK.png",
"sequential_image_generation": "disabled", "response_format": "url", "size": "2K", "stream": false, "watermark": true }'