Seedream 4.5

Seedream 4.5 is a next-generation image generation and editing model released by ByteDance's Seed team in December 2025, achieving comprehensive improvements over Seedream 4.0 through overall model scaling. The model integrates image generation and editing capabilities into a unified architecture, ranking #10 on the LM Arena global leaderboard with a score of 1147, placing it among the top AI image generators.

Seedream 4.5's hallmark breakthrough is precise, legible text rendering — generating correctly spelled, stylistically diverse text within images, from taglines to long paragraphs, from handwritten to serif fonts. Combined with designer-level composition capabilities, the model can directly output posters, logos, and marketing visuals with proper typographic hierarchy, dramatically reducing post-production work. The model also achieves cinematic-quality lighting and material handling for complex surfaces (glass, metal, fabric), performing exceptionally well in low-light and reflective scenarios.

Key Capabilities

• Precise Text Rendering: Industry-leading in-image text generation supporting Chinese, English, Japanese, Korean and multiple font styles — directly generate posters, packaging, and UI mockups with accurate text.
• Native 4K Resolution: Supports up to 4096×4096 native output without post-upscaling — skin pores, fabric textures, and distant details remain crisp and print-ready.
• Unified Generation & Editing: A single model supports both text-to-image generation and natural language editing of existing images (background replacement, lighting adjustment, clothing changes, typography modifications, etc.).
• Multi-Image Reference Editing: Accepts up to 10 reference images simultaneously, accurately identifying subjects and strictly preserving facial features, lighting, and color tone details from references for high-consistency multi-source composition.
• Material & Lighting Fidelity: Deep understanding of lighting behavior on complex materials like glass, metal, and fabric — low-light and reflective scenes achieve cinematic-level realism.
• Character & Style Consistency: Maintains character appearance, clothing, posture, and visual style across multi-image generation, suited for brand assets and serial content creation.
• Multiple Aspect Ratios: Supports various aspect ratio and resolution configurations, flexibly adapting to social media, advertising, and print scenarios.

Technical Strengths

Feature	Benefit
Text rendering precision	Accurately renders everything from taglines to dense paragraphs with multilingual and typographic style support, solving the "gibberish text" industry pain point in AI images
Native 4K output	High pixel density ensures skin pores, fabric textures, and distant details remain crisp and sharp — output is immediately print and large-format display ready
Unified architecture	Generation and editing in one model eliminates switching between tools — natural language instructions handle complex image modifications
Material physics understanding	Deep understanding of complex lighting and material physics — glass refraction, metal reflection, and fabric folds are rendered with high realism
Editing consistency	Strictly preserves subject details, lighting, and color tone from reference images during edits, ensuring visual consistency for brand assets
Instruction-following precision	Significant improvements in prompt adherence, alignment, and aesthetics over Seedream 4.0 on the internal MagicBench benchmark