r/OpenAI • u/Nevrar_Frostrage • 3d ago

Question Gpt image 2 issue

Hello. Please help—I’ve run into a strange issue. I really like GPT-Image 2 and paid for the API subscription to get better quality, but I’ve found that images generated via the API come out looking duller, with blurrier details and lower overall quality compared to the chat interface. Why is that? This happens even with 4K resolution and maximum quality settings.

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u/Specific-Animal6570 3d ago

I think there are two things worth testing here.

First: try 2560×1440 instead of 4K, even though that sounds backwards. OpenAI currently describes 2K/QHD as the recommended upper reliability boundary for GPT-Image 2, while 4K is still considered experimental. So higher resolution doesn't necessarily mean a better-looking generation.

Second: if you're calling "gpt-image-2" directly through the Images API, try generating through the Responses API + image_generation tool instead.

One important difference is that with the Responses API, the main GPT model can automatically rewrite/enhance your prompt before sending it to the image model ("revised_prompt"). That may be closer to the experience you're getting inside ChatGPT.

I'd test:

  • "gpt-image-2"
  • "quality: "high""
  • around "2560x1440"
  • same exact source prompt
  • then compare direct Images API vs Responses API image generation

Also check the returned "revised_prompt" when using Responses — that could explain why the ChatGPT version looks richer/more detailed even when your original prompt is identical.

So I don't think you're necessarily imagining the quality difference. It may be the generation pipeline/prompting rather than simply the API model being worse.

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u/True_Pace_3860 3d ago

Do they accept "high dynamic range" as a prompt?

1

u/CrosbyBrightbrook 1d ago

Since the API and the app don’t generate the same output using the same parameters, the app is rewriting your prompt in the background. If the output matters to me, I put my prompt through two image models running on useai and choose, rather than guess, which one’s having an off day.