FLUX.1 [schnell] — 12B-param speed-optimised model by Black Forest Labs. Sub-second generation at $0.003/MP. Apache 2.0 licensed.
Different FLUX.1 variants for different speed, quality, and cost trade-offs — all on the same Runflow API.
Speed-optimised — sub-second generation at $0.003/MP, Apache 2.0
Open-weight, 12B params, $0.025/MP — production, LoRA, general purpose
$0.04/MP — commercial-grade, highest quality in the FLUX.1 family
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 | Moderate | Fast drafts with decent quality — ideal for previews and iteration |
| Fashion | Moderate | Good for rapid concept exploration at high volume |
| Product | Moderate | Quick product shot drafts before committing to a premium model |
| Creative | Strong | Excellent for brainstorming and rapid creative exploration |
Full parameter reference for the flux-1-schnell model endpoint.
| Parameter | Type | Description |
|---|---|---|
| prompt | string | Text description of the image to generate. |
| image_size | object | string | Output size. Presets: square_hd, square, portrait_4_3, portrait_16_9, landscape_4_3, landscape_16_9. Or custom {width, height}. Default: landscape_4_3. |
| num_inference_steps | integer | Number of denoising steps. Range: 1–4. Default: 4. Lower = faster, higher = more detail. |
| guidance_scale | float | How closely the model follows the prompt. Range: 1–20. Default: 3.5. |
| acceleration | string | Speed optimisation level. Options: "none", "regular", "high". Default: "regular". Higher = faster at minor quality cost. |
| num_images | integer | Number of images to generate per request. Range: 1–4. Default: 1. |
| output_format | string | Output format. Options: "jpeg", "png". Default: "jpeg". |
| enable_safety_checker | boolean | Enable NSFW content filtering. Default: true. |
| seed | integer | Random seed for reproducible outputs. |
| sync_mode | boolean | Return media as data URI without storing in request history. Default: false. |
Flux AI models are available on many platforms. Here's what makes the Runflow image generation API different.
FLUX.1 [schnell] is distilled for speed — 1 to 4 inference steps produce usable images in under a second, making it ideal for real-time previews and high-throughput pipelines.
~8× cheaper than FLUX.1 [dev]. A 1024×1024 image costs $0.003. At this price point, you can generate thousands of drafts before committing to a premium model for final output.
The acceleration parameter (none/regular/high) lets you push speed even further when sub-second isn't fast enough — useful for live preview UIs and interactive design tools.
No licensing restrictions. Use it commercially, fine-tune it, deploy it however you need. Weights and outputs are both unrestricted.
Even at high speed, every output is scored by Runflow's Sentinel system before delivery, catching low-quality 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.