How can I change the body type or size of models in my product images using AI?

Customers need to visualize themselves wearing your clothes. When product photos only show one body type—especially if it's a narrow, idealized silhouette—many potential buyers can't see how the garment would fit or look on them. This directly impacts conversion: if someone can't picture themselves in your product, they're less likely to purchase. For products with multiple size options, showing different body types across your product page helps customers understand how the item adapts to different frames, which reduces returns and builds trust.

The traditional solution is hiring multiple models for your photoshoot, but that multiplies costs and time. A single model photoshoot is already expensive; adding three or four more models to represent different body types can make it prohibitively costly. Photoshop editing is technically possible, but making body modifications look realistic is extremely difficult—the proportions, lighting, and fabric draping rarely match up convincingly. Generic AI tools like ChatGPT or Midjourney can change body types, but they often alter your product in the process: shifting colors, distorting garment proportions, or changing how the fabric sits. You end up with a different model and a different product.

Tools built specifically for fashion product photography, like Nightjar, are fine-tuned to understand the distinction between your product and the model. You upload your existing model photo, then type instructions like "make the model plus size," "make the model taller," or "change their body type to athletic build" directly into the prompt. The AI modifies only the model's body shape, height, and proportions while preserving your product's exact fit, colors, text, and material details. Because these tools are trained on product photography, they know that the product is the constant and everything else can change.

If you don't have a model photo to start with, Nightjar also lets you upload just your product image without a model. You can generate an AI model with the specific body type and size you want, and the tool will create a realistic image of someone wearing your product. This means you can create diverse product imagery even when you haven't shot with multiple models, giving you the flexibility to represent different body types without the cost of additional photoshoots.