A comparison of 20 image-generation models found that one default image cost between $0.006 and $0.134, a 22-fold spread under the same prompt and size. OpenRouter ran the tests through its Image API and used the charge returned with each completed request rather than trying to reconcile list prices expressed per token, megapixel or image.
OpenAI’s GPT Image 2 was the cheapest model measured, billing $0.006 for a short prompt and $0.0135 for a longer product-image prompt. Five of six models in a smaller text-rendering test printed both requested lines correctly, including that low-cost option. OpenRouter stresses that the result covers only the tested prompts; a higher-priced model may perform better on difficult compositions or longer text.
Settings can move costs substantially. Changing GPT Image 2 from its default quality to high raised one image from $0.006 to $0.211 and increased completion time from 12 to 123 seconds. Output formats, reference-image limits and repeatable seed support also vary by model. OpenRouter measured prices on September 11 and warns that catalog details change quickly. Its practical recommendation is to test shortlisted models on the actual workload, read the returned usage cost and avoid assuming that either price or leaderboard position predicts the best result.