imgix APIs
Rendering API
Fill Generative Negative Prompt

Fill Generative Negative Prompt


Premium Feature

Fill Generative Negative Prompt is currently available for imgix customers on a Premium plan. If you’re interested in this feature, please contact our sales team (opens in a new tab) to get more information on this feature.

Provides a negative text suggestion to the output of fill=gen. It accepts URL-safe string values but can also be base64 encoded (fill-gen-neg-prompt64).

Generative fill using fill-gen-prompt=eagle%20flying%20around:

Original example using generative fill prompt,format

Suggest that clouds not be used with fill-gen-neg-prompt=clouds:

Cropped image using generative fill and a negative keyword,format&fill-gen-neg-prompt=clouds

Prefer Base64 Variant

imgix recommends using the Base64 variant version of this parameter to make encoding values easier.


Guarantee of keyword output

While fill-gen-neg-prompt suggests what not to display in the final output, it does not guarantee those keywords will not be used in the final generative fill.

For example, using the negative prompt keywords fill-gen-neg-prompt=clouds,trees,sky,black%20bird outputs an image that does not have clouds or trees, but it still has a black-colored bird even if we suggested that black-colored birds not be included.

Fill generative image missing an eagle,format&fill-gen-neg-prompt=clouds,trees,sky,black%20bird

Character limits

There is no direct character limit for prompt values, though we recommend keeping your image URLs under 1024 characters.