Seedream 4 Edit API

bytedance/seedream/v4/edit
1–10 images · 1K/2K/4K · n 1–15

Seedream 4 Edit combines 1–10 reference images with natural language prompts for mask-free editing and multi-image fusion. It executes targeted modifications while preserving source facial identity, composition, and realistic lighting.

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Input
Required0/5000
Required0/10
Optional
Optional
Optional
OutputIdle

Generated images will appear here

Estimated cost: —
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Examples

edit-01-output.jpg

Combine the three reference images into one natural documentary photograph. Use the elderly bookbinder from image 1 with exactly the same face, wrinkles, eyes, grey beard, navy galabeya, brown leather apron and silver cross. Use only the goatskin cover, gold-and-red interlaced cross, brass bosses and leather ties from image 2; do not copy the white table or the isolated still-life setup. Set the scene in the Cairo workshop from image 3 with its mashrabiya window, wooden press, shelves of quires and the ochre street beyond. The man stands in three-quarter view at the table, pressing the finished cover onto a text block in the wooden press. Relight him and the book with the same warm low afternoon sun from the left and matching lattice shadows, consistent scale and perspective, no text, no watermark.

edit-02-output.jpg

Extend image 1 into a wide 16:9 photograph. Keep the clove basket, the crate, the slatted shutter and the stripe of sun exactly as they are, with the same size, angle and relative position. Naturally expand the scene on both sides and upward: to the left reveal more of the loft with stacked jute sacks of cinnamon bark and a hanging brass scale; to the right open a doorway onto a bright stone stair and a glimpse of a turquoise harbor; above, show the timber rafters and a few swallows on a beam. Seamless continuation of the same late-afternoon light, dust motes and wood grain with no visible seams or borders, no text, no watermark.

edit-03-output.jpg

Redraw image 1 in the exact visual style of image 2. Image 1 defines all content: keep the same high terrace viewpoint and framing, the honeycomb vats, the tanners in the same positions, the drying skins and the surrounding stone walls. Image 2 defines only the style: a cyanotype on textured watercolor paper with a Prussian-blue ground, white or pale-blue highlights, slightly uneven chemical wash and visible paper fibers. Do not copy any ferns, plants or botanical shapes from image 2. No text, no signature, no watermark.

Seedream 4 Edit

Seedream 4 Edit is a high-fidelity image editing model developed by the ByteDance Seed team. Built on a unified DiT architecture, it natively supports 1 to 10 reference images for mask-free localized modifications, texture replacement, and cross-scene fusion. The model strictly maintains subject identity and outputs up to 4K resolution at 5 credits ($0.025) per image.

Why Choose Seedream 4 Edit API?

  • 1–10 Reference Image Fusion & Semantic Role AssignmentNatively accepts 1 to 10 ordered reference images, allowing intuitive prompts like "use Image 1 for the subject and Image 2 for the background" to blend multi-source assets into a cohesive visual.

  • Mask-Free Natural Language Editing & Texture ReplacementEliminates cumbersome manual masking; describe edits in conversational language to achieve localized color correction, background changes, atmospheric transitions, and realistic material swaps.

  • Subject Identity & Environmental Lighting PreservationUtilizes deep feature decoupling and spatial reasoning to maintain facial identity, hair texture, and natural environmental illumination while modifying attire, background, or pose.

  • 1–15 Batch Variations & Flexible Multi-Aspect RatiosGenerates multiple compositional or stylistic variations in a single run across eight standard aspect ratios and up to 4K resolution, accelerating design exploration and asset turnaround.

Parameters

ParameterRequirementDescription
promptRequired

Describe the requested changes in 1–5,000 characters. Leading and trailing whitespace is not counted.

image_urlsRequired

1–10 ordered HTTP(S) reference image URLs. The number of image_urls plus n totals 15 or fewer.

sizeOptional

Output aspect ratio. Defaults to 1:1.

Default1:13:44:316:99:163:22:321:9
resolutionOptional

Output resolution preset: 1K, 2K, or 4K. Defaults to 2K.

Default2K1K4K
nOptional

Number of images to generate: integer 1–15. Defaults to 1. The number of image_urls plus n totals 15 or fewer.

Default123456789101112131415

How to Use

  1. Prepare and Supply Reference ImagesGather 1 to 10 accessible HTTP(S) image URLs or upload local images in the console, noting the order and key elements of each asset (such as character, background, or prop).

  2. Draft Clear Editing Prompts with Asset ReferencesExplicitly reference images in your prompt, e.g., "Place the character from Image 1 into the beach setting of Image 2, retaining the face and attire from Image 1 under warm sunset lighting."

  3. Configure Ratios, Batch Count, and Retrieve AssetsChoose the aspect ratio, resolution (1K, 2K, or 4K), and image count n (ensuring reference images plus n totals 15 or fewer), then submit the task asynchronously to retrieve your output URLs.

Pricing

Each image costs 5 credits ($0.025). The total is 5 × n credits, where n is the number of generated images.

UsageRateDetails
Standard generation5 credits/image · $0.025/image5 × n credits · $0.025 × n
n = 1 / 5 / 10 / 145 / 25 / 50 / 70 credits$0.025 / $0.125 / $0.250 / $0.350

Best Use Cases

  • E-Commerce Merchandising & Background ReplacementSeamlessly composite studio product or model photography into diverse lifestyle environments, automatically harmonizing perspective and contact lighting while keeping product geometry intact.

  • Multi-Asset Feature Extraction & Visual FusionCombine character designs, specific garments, and environment concepts across multiple input images into unified marketing collateral and brand visuals.

  • Mask-Free Portrait Refinement & Detail SwappingModify hair styles, clothing colors, accessories, or background ambiance without manual masks, ensuring complete facial identity preservation and natural skin textures.

  • Multi-Angle Concept Exploration & Batch IterationUse reference assets with batch generation (n > 1) to explore multiple lighting conditions, camera angles, and framing layouts in parallel for rapid pre-production sign-off.

Pro Tips

  • Explicitly Assign Asset Roles: Clearly designate the purpose of each reference in the prompt (e.g., "Image 1 is the main subject, Image 2 is the background, and Image 3 is the clothing style") to prevent semantic confusion.
  • Use Structured Preservation Commands: Frame instructions affirmatively specifying what to freeze and what to change (e.g., "Retain the facial identity and hair from Image 1 while changing the background to a modern architectural loft").
  • Harmonize Lighting Across Sources: Specify a dominant light direction and color temperature (such as "unified warm golden-hour sidelight") so composited elements seamlessly blend with the new environment.
  • Plan Around Total Image Limits: Ensure that the number of reference images plus generated images n does not exceed 15 (for example, if uploading 5 references, n can be at most 10).

Notes

  • Image Edit Endpoint Input Scope: This endpoint requires 1 to 10 publicly accessible HTTP(S) image URLs (PNG, JPEG, or WEBP). To generate images purely from natural language text, use the Seedream 4 Text to Image endpoint.
  • Total Asset and Output Ceiling: The total count of reference images in image_urls plus the output count n cannot exceed 15, and the prompt must be between 1 and 5,000 characters.
  • Zero Surcharge for Inputs & Full Refund Guarantee: Inputting reference images is completely free of charge; you are billed strictly for generated images at 5 credits each. Any failed task triggers an immediate and automated credit refund.

Related Models

Seedream 4 Edit API frequently asked questions

What is the Seedream 4 Edit API?

Seedream 4 Edit is a ByteDance Seed model for multi-image fusion and high-fidelity image editing. It natively accepts 1–10 reference images, provides mask-free localized adjustments, semantic role assignment, and cross-scene asset composition, with batch generation of 1–15 variations. Built on an efficient Diffusion Transformer (DiT) and high-compression VAE unified architecture, it utilizes deep feature decoupling and spatial reasoning to follow instructions closely while preserving facial identity, fine textures, and realistic environmental lighting. You can call it programmatically or try it from the playground above.

How many reference images does Seedream 4 Edit support?

Seedream 4 Edit natively supports 1 to 10 ordered reference images via publicly accessible HTTP(S) URLs (PNG, JPEG, or WEBP). In your prompt, you can use clear designations such as "Image 1" and "Image 2" to assign semantic roles (such as main subject, replacement background, or clothing reference) for high-fidelity multi-source composition.

Is manual masking required to use Seedream 4 Edit?

No. Seedream 4 Edit employs an advanced mask-free editing paradigm without requiring manual selection painting or mask uploads. Guided by deep natural language understanding, the model automatically pinpoints the target regions described in your prompt and executes seamless replacements with harmonious lighting boundaries.

How does Seedream 4 Edit maintain subject identity consistency?

The model incorporates deep facial feature decoupling and identity-locking representations. When modifying environments, clothing, or poses according to your prompt, it maintains facial bone structure, skin texture, and expressive characteristics to prevent identity drift or distortion.

What is the total image limit for Seedream 4 Edit?

In any single request, the sum of reference images in image_urls (1–10) plus the generated images n (1–15) cannot exceed 15. For instance, if you submit 3 reference images, n can be up to 12; if you supply 10 reference images, n can be up to 5.

Can Seedream 4 Edit change the image aspect ratio or resolution?

Yes. When submitting an edit request, you can freely specify the size parameter across eight aspect ratios (such as 16:9, 9:16, or 1:1) and configure the resolution parameter to 1K, 2K, or 4K. The model intelligently extends boundaries and recomposes spatial elements to fit the desired aspect ratio.

Does providing multiple reference images increase the cost for Seedream 4 Edit?

No. Seedream 4 Edit is billed strictly based on the number of generated images, at 5 credits ($0.025) per image. Supplying anywhere from 1 to 10 reference images incurs no additional fees. If a task fails, all pre-deducted credits are automatically refunded.