ByteDance Seedream 4.0 Preview: Can It Be a Nano‑Banana Alternative Made in China?

Generative AI image models are rapidly becoming indispensable tools for designers, marketers and artists. After Google released Gemini 2.5 Flash Image—better known by its catchy nickname nano banana—the model set a high bar for fast, photorealistic image edits through plain‑language commands. Now ByteDance, the tech giant behind TikTok and Douyin, is testing Seedream 4.0, a multimodal image‑generation model that promises even greater creative freedom. This preview dives into the features announced for Seedream 4.0, compares them with nano‑banana, and offers prompt‑engineering tips to help you decide whether this “made‑in‑China” upstart could be a viable alternative.

What Is Seedream 4.0?

Seedream 4.0 is ByteDance’s next‑generation AI model for generating and editing images. It is billed as a multimodal platform that combines text‑to‑image synthesis, reference‑based editing and batch image creation in a single system. Its mixture‑of‑experts (MoE) architecture delivers 2K‑resolution images in about 1.8 seconds, enabling near‑real‑time workflow. Beyond speed, Seedream 4.0 integrates text‑to‑image generation, image editing and enhancement into one tool, eliminating the need to switch between applications and ensuring consistent output quality. The platform supports up to six reference images and can output up to nine matching images simultaneously, making it ideal for series creation, storyboards and product catalogues.

Core features and innovations

Seedream 4.0 introduces several technical and creative upgrades:

• Blazing‑fast generation – High‑resolution images (2048×2048 pixels) appear in about 1.8 seconds thanks to the model’s MoE design, with support for up to 4K resolution for ultra‑sharp outputs.
• Integrated multimodal editing – The model consolidates text to image generation, image editing and enhancement tasks, allowing users to describe changes in natural language and apply them without masks or bounding boxes. For example, you can ask Seedream 4.0 to “add a helmet,” “remove the background,” or “replace the outfit” and it performs the edits directly.
• Advanced multi‑reference processing – Users can upload up to six reference images to guide style, composition or character identity and generate up to nine coherent outputs at once. This multi‑reference capacity helps maintain character consistency across multiple angles or scenes.
• Batch generation technology – Seedream 4.0 can produce several variations of a scene simultaneously while preserving overall style and theme. This is valuable for product shoots, marketing campaigns or storyboarding where a series of related images are needed.
• Native bilingual support – The platform is designed to handle both Chinese and English prompts with high accuracy, making it suitable for global creators and local Chinese markets.

Insights from Early Testing

Early testers report that Seedream 4.0 represents a huge leap forward over version 3.0 and highlight three core improvements:

1. Improved text‑to‑image synthesis – The model listens to prompts more accurately, supports higher resolutions and is extremely fast, producing a 2K image in less than 1.8 seconds.
2. Enhanced image editing – Users can upload one or more photos and issue plain‑language commands to add, remove or modify elements; the model performs the edits precisely.
3. Group generation – Seedream 4.0 can create whole sets of related images in a single run, making it a lifesaver for brainstorming or storyboarding.

Early evaluations identify five standout features:

• Natural‑language editing – You can instruct the model to “remove the people in the background,” “add a helmet” or “replace this with that,” and it executes without needing complicated prompts.
• Character consistency across styles – Seedream 4.0 remembers a character’s face and preserves details even when generating them in different art styles or 3D renders.
• Deep understanding of abstract ideas – The model interprets vague or imaginative descriptions and transforms them into concrete visuals.
• Multi‑image input and output – It can combine multiple images, transfer styles and produce storyboards or series with consistent characters and themes.
• Super‑fast, high‑resolution results – Seedream 4.0 supports resolutions up to 4K and maintains sharpness and realism.

These improvements showcase the model’s versatility. However, Seedream 4.0 is still in internal testing, and public access is expected soon.

Use Cases and Applications

Seedream 4.0 aims to serve both creative and commercial needs. The multi‑reference and batch generation features make it useful for:

• E‑commerce and marketing – Brands can quickly produce product variations, lifestyle shots and advertising visuals that maintain consistent style and identity across campaigns.

• Storyboard and comic creation – Generating coherent sequences of images helps artists and filmmakers build narratives or plan shots without manually editing each frame.

• Interior and concept design – Designers can upload sketches or photos and ask the model to refine the scene, adjust lighting or change styles, producing high‑resolution renderings for presentations or client approvals.

• Fan art and illustration – The model’s ability to mix multiple references and remember character identities makes it well suited for creating stylised portraits, anime characters or collectibles.

Nano‑Banana vs. Seedream 4.0

Google’s nano‑banana (Gemini 2.5 Flash Image) is the current benchmark for AI image editing. It offers precise local edits, merges multiple reference images into a single output and preserves identity across iterations. But early reports suggest several ways Seedream 4.0 differentiates itself:

While nano‑banana remains a trusted option for precision editing, Seedream 4.0’s focus on high resolution, batch generation and creative flexibility may appeal to artists and designers who need more than simple touch‑ups.

Prompt‑Engineering Tips for Seedream 4.0

Early testers and ByteDance’s own guides suggest that clear, structured prompts are key to unlocking Seedream 4.0’s capabilities. Here are some best practices drawn from the model’s feature set and general prompt‑engineering principles:

1. Use the “action + object + attributes” format. Commands should specify the transformation (add, remove, replace, change), the target element and desired characteristics. For example: “Add a golden helmet to the knight” or “Change the background to a bamboo forest while keeping the subject’s clothing and expression intact.” This structure clarifies what should change and what should remain the same.
2. Upload reference images to anchor identity and style. Seedream 4.0 allows up to six references. Provide photos or sketches showing your subject from different angles or in different outfits to help the model maintain consistency across outputs. When blending multiple references, use prompts like “Combine the man from image 1 and the woman from image 2 into one scene; follow the pose in image 3.”
3. Trigger batch creation with words like “series” or “set.” To generate multiple related images, include phrases such as “Generate a series of four product mockups in the same style” or “Create a set of five storyboard panels showing different angles.” Seedream 4.0’s batch mode produces up to nine images at once, ideal for comics, storyboards or product variations.
4. Incorporate style descriptors for artistic results. Unlike nano‑banana, Seedream 4.0 supports various art styles and filters. Specify aesthetic cues like “in ukiyo‑e style,” “cyberpunk lighting,” or “as a clay sculpture” to guide the model. You can also reference the style of a particular artist or medium (e.g., “in the style of watercolor illustration”) for more targeted results.
5. Iterate with refinement prompts. After generating a base image, you can refine it with follow‑up instructions: “Reduce the glare on the product surface,” “Adjust the lighting to sunset warm,” or “Remove the person in the background.” Seedream 4.0 is designed for iterative editing, so incremental prompts yield better results than trying to do everything at once.
6. Specify what should NOT change. To preserve character identity and important features, explicitly state constraints: “Keep the woman’s facial features and clothing unchanged while changing the background,” or “Change only the haircut; preserve the skin tone and expression.” This helps the model respect the original elements and avoid unintended modifications.

Access, Pricing and Availability

At the time of writing, Seedream 4.0 is available only to beta testers. ByteDance plans to roll it out through its own creative platforms and later via an API for developers and enterprise customers. The model is expected to offer a free trial and support exports in 2K or 4K resolution. It can combine multiple photos into one design and generate up to nine images in one go, keeping style and character consistent.

ByteDance has not released detailed pricing at the time of this preview. Nano‑banana, by contrast, has transparent pricing and is already available via the Gemini app, and the third parties like DeeVid AI Image Generator.

Conclusion: A Rising Challenger

Seedream 4.0 is an ambitious entry into the AI image‑generation arena. It promises lightning‑fast 2K/4K rendering, multi‑image blending and batch output, natural‑language editing and creative style flexibility. These features address some of nano‑banana’s weaknesses, particularly in artistic variation and multi‑image workflows. Early reviews praise the model’s character consistency and deep understanding of complex prompts. For designers, illustrators and marketers who need high‑resolution, coherent series of images, Seedream 4.0 could be a game‑changer.

However, prospective users should temper expectations until the model’s beta ends and independent benchmarks are available. Nano‑banana remains a proven tool with transparent pricing and strong performance in realistic edits. Seedream 4.0’s success will depend on ByteDance delivering on its speed and quality promises, providing robust API access and establishing trust beyond promotional claims. If it lives up to the hype, Seedream 4.0 could become the first widely adopted, home‑grown alternative to the dominant models coming out of Silicon Valley.