Runflow
Stability AI

SDXL Image-to-Image API

SDXL's image-to-image variant — transform existing images with text prompts and adjustable strength control. Full LoRA and embedding support with the same 50,000+ community ecosystem.

sdxl-image-to-image3.5B paramsUNet-based latent diffusion with dual CLIP text encoders
Updated March 2026·Early access
Price
~$0.003/image
Usage-based, per compute second
Latency
~2–4s
25 steps at 1024×1024
Cold Start
5–10s
Not billed · handled by Runflow
Category
Image Editing
image-to-image

SDXL family by Stability AI

Explore all variants in the SDXL family available on Runflow.

SDXL

Standard

Standard 3.5B text-to-image generation

SDXL Image-to-Image

Image-to-Image

Image-guided generation with strength control

SDXL Inpainting

Inpainting

Mask-based region editing

SDXL Lightning

Fast

1–4 step generation, sub-second latency

SDXL ControlNet Union

ControlNet

10+ ControlNet types in one model

SDXL Fooocus

Enhanced

Enhanced quality with automated prompt optimization

Benchmarked for your use case

Every model on Runflow is scored per vertical — not generic leaderboard numbers. Scores come from domain-expert evaluation on real production prompts.

Use CaseAssessmentNotes
PortraitPendingPortrait editing quality
FashionPendingFashion editing quality
ProductPendingProduct editing quality
CreativePendingCreative editing quality

API Parameters

Full parameter reference for the sdxl-image-to-image model endpoint.

ParameterTypeDescription
promptstringText description of the desired output. Works with both natural language and keyword-style prompts.
image_urlstringURL of the input image. Accepts JPEG, PNG, WebP, GIF, AVIF.
strengthfloatHow much the generated image departs from the input. 0.05 = subtle; 1.0 = full regeneration. Default: 0.95.
negative_promptstringHighly effective on SDXL — describe what to exclude from the output.
image_sizeobject | stringOutput dimensions. Presets: square_hd, square, landscape_4_3, landscape_16_9, portrait_4_3, portrait_16_9. Or custom {width, height}.
num_imagesintegerNumber of images to generate. Range: 1–8. Default: 1.
num_inference_stepsintegerDenoising steps. 20–25 for standard, 30–50 for max fidelity. Default: 25.
guidance_scalenumberClassifier Free Guidance. 7–9 recommended. Default: 7.5.
seedintegerReproducibility seed. Same seed + same parameters = identical output.
lorasarray[object]Array of LoRA weights to apply. Stack multiple LoRAs for combined effects.
embeddingsarray[object]Textual inversion embeddings to apply during generation.
preserve_aspect_ratiobooleanMaintain input image aspect ratio. Default: false.
expand_promptbooleanAuto-expand prompt with additional detail via LLM. Default: false.
formatstringOutput image format. Options: "jpeg", "png". Default: "jpeg".
enable_safety_checkerbooleanEnable content safety filter. Default: true.
sync_modebooleanIf true, returns the image as a data URI.

Technical Specifications

ArchitectureUNet-based latent diffusion (3.5B base UNet, dual CLIP text encoders)
Parameters3.5B (base); ~6.6B with refiner
Input FormatsJPEG, PNG, WebP, GIF, AVIF
Max Resolution1024 × 1024 native
Strength Range0.05–1.0 (controls departure from input)
VRAM7–8 GB (FP16)
Output FormatJPEG, PNG
LoRA SupportYes — 50,000+ community LoRAs on Civitai
LicenseCreativeML Open RAIL++-M (no revenue restrictions)

Why run SDXL Image-to-Image on the Runflow API

Flux AI models are available on many platforms. Here's what makes the Runflow image generation API different.

Adjustable strength control

Fine-tune how much the output deviates from the input image — from subtle tweaks (0.05) to complete reimagining (1.0) — all with a single parameter.

Full LoRA ecosystem

Apply any of 50,000+ community LoRAs during image-to-image generation for style transfer, character consistency, and domain adaptation.

Effective negative prompts

Unlike newer models, SDXL's negative prompt system is highly responsive — giving precise control over what to exclude from edited outputs.

Aspect ratio preservation

Optional preserve_aspect_ratio flag maintains the input image's proportions — no manual calculation or cropping needed.

Battle-tested pipeline

The same proven SDXL architecture used in millions of production workflows, now applied to image-guided generation.

Explore other models

Same API, different strengths. Switch models with one parameter change.

Frequently asked questions

Resources

Start generating images with SDXL Image-to-Image

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