
Google Imagen is Google's premier text-to-image diffusion model, excelling in photorealistic, high-resolution image generation from textual prompts with unmatched detail, creativity, and adherence to complex descriptions.

[Core Function] Imagen 4.0 Fast is a high-speed text-to-image model optimized for rapid visual generation. [Strengths] It offers incredible generation speed (approximately 2.7 seconds) and high cost-effectiveness while maintaining excellent text rendering inside images. [Best For] Highly recommended for rapid prototyping, quick design iteration, high-volume image generation, social media thumbnails, blog hero images, and UI mockups. [Limitations] Do NOT use this model if you require 2K resolution (it does not support the imageSize parameter) or the absolute highest cinematic fidelity and strict prompt alignment. Does not support negative prompts or native image editing. [Routing] Choose this model when the user emphasizes 'fast', 'quick', 'rapid', or needs high-volume, low-latency generation.

[Core Function] Imagen 4.0 Ultra is Google's premium text-to-image model optimized for the highest quality and instruction alignment. [Strengths] It delivers ultimate photorealistic detail, superior texture rendering, and extremely strict adherence to complex, multi-part prompt instructions, supporting up to 2K resolution. [Best For] Highly recommended for high-end commercial marketing assets, professional design, intricate artistic compositions, and scenarios where precise instruction-following is paramount. [Limitations] Do NOT use this model if you need instant/real-time generation, native image editing (inpainting/outpainting), or negative prompts. It is the most expensive tier in the Imagen family. [Routing] Choose this model when the user demands the absolute highest quality, ultimate detail, or has highly complex prompt instructions. Otherwise, default to standard Imagen 4.0 or Imagen 4.0 Fast.

[Core Function] Imagen 4.0 is Google's flagship professional-grade text-to-image model designed for high-fidelity visual generation. [Strengths] It excels at industry-leading photorealism, exceptional typography/text rendering inside images, and strong prompt adherence, supporting up to 2K resolution and batch generation. [Best For] Highly recommended for general high-quality image generation, marketing assets (posters, product labels, menus, signage), and product photography mockups where readable text is required. [Limitations] Do NOT use this model if you need instant/real-time generation, native image editing (inpainting/outpainting), or negative prompts. It is strictly an image-only output model. [Routing] Use this model by default for high-quality, photorealistic text-to-image requests. If the user emphasizes speed or needs lower cost, route to Imagen 4.0 Fast. If the user demands the absolute highest detail and prompt precision, route to Imagen 4.0 Ultra.