GPT-Image 1.5 by OpenAI — high-fidelity images with strong prompt adherence. Three quality tiers, three sizes, transparent background support. From $0.009/image.
Two variants for generation and editing — all on the same Runflow API.
Text-to-image with quality × size pricing tiers
Image editing and inpainting variant
Every model on Runflow is scored per vertical — not generic leaderboard numbers. Scores come from domain-expert evaluation on real production prompts.
| Use Case | Assessment | Notes |
|---|---|---|
| Portrait | Strong | High-fidelity faces with strong prompt adherence |
| Fashion | Strong | Detailed editorial-quality imagery |
| Product | Strong | Transparent background support, accurate rendering |
| Creative | Strong | Versatile artistic generation across quality tiers |
| Quality | 1024×1024 | 1024×1536 | 1536×1024 |
|---|---|---|---|
| Low | $0.009 | $0.013 | $0.013 |
| Medium | $0.034 | $0.051 | $0.050 |
| High | $0.133 | $0.200 | $0.199 |
Also charged: $0.005 per 1K input text tokens · $0.010 per 1K output text tokens (model reasoning).
Full parameter reference for the gpt-image-1.5 model endpoint.
| Parameter | Type | Description |
|---|---|---|
| prompt | string | Text prompt describing the image to generate. 2–32,000 characters. |
| quality | string | Output quality tier. Options: "low", "medium", "high". Default: "high". Affects price. |
| image_size | string | Image dimensions. Options: "1024x1024", "1536x1024", "1024x1536", "auto". Default: "1024x1024". Use "auto" to let the model pick the best size. |
| background | string | Background type. Options: "auto", "transparent", "opaque". Default: "auto". |
| input_fidelity | string | Controls how strictly the model follows the input prompt. Options: "low", "high". Default: "high". |
| num_images | integer | Number of images to generate. Range: 1–4. Default: 1. |
| output_format | string | Output format. Options: "jpeg", "png", "webp". Default: "png". |
| sync_mode | boolean | Return media as data URI without storing in history. Default: false. |
Flux AI models are available on many platforms. Here's what makes the Runflow image generation API different.
Choose low, medium, or high quality at three size options — 9 price points from $0.009 to $0.200 per image, letting you optimise cost for every use case.
Native transparent background output — no post-processing removal needed for product photography on white or overlay use cases.
GPT-Image 1.5 is OpenAI's highest-quality image generation model, built on the same foundation as their multimodal research.
Every output is scored by Runflow's Sentinel system before delivery, catching low-quality or off-prompt results automatically.
Same API, different strengths. Switch models with one parameter change.
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Get API access in minutes. No GPU setup, no infrastructure to manage. Pair with Sentinel to control the quality of every AI-generated image you ship.