Stable Diffusion XL

Name: Stable Diffusion XL
Brand: Stability AI
SKU: stable-diffusion-xl
Price: 0.0015 USD
Availability: InStock

Image generationAvailable

by Stability AIstable-diffusion-xl

Stability AI's SDXL model via Replicate. High-quality image generation with extensive customization.

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Price: ≈ $0.0015/run
Input → output: Text → Image
Developer: Stability AI
Updated: September 23, 2026

Playground

Try Stable Diffusion XL

Input & output

≈ $0.0015/run

Prompt

Advanced settings (3)

Negative prompt(optional)

Width(optional)

Height(optional)

⌘/Ctrl + Enter

Output

Your image appears here.

This run

about $0.0015 · 0.15 credits

$0.0044 (0.44 credits) are reserved at the start; the actual GPU time is billed.

New here?

10 free credits ($0.10) when you sign up with Google

Usable 24 hours after sign-up, up to 5 runs per day and at most 2 credits per run. Other sign-in methods start without credits. Enough for 22 runs of this model.

Examples

Real outputs from the public examples of this model on Replicate, with the prompt and settings that produced them. They were not generated live on this page.

Open full size
Prompt
An astronaut riding a rainbow unicorn, cinematic, dramatic
Settings
width

768
height

768
Open full size
Input
Prompt
A rainbow coloured bear
Settings
width

1024
height

1024
Open full size
Prompt
An astronaut riding a rainbow unicorn, cinematic, dramatic
Settings
width

1024
height

1024

Example prompts

Examples from the Railwail catalog. They were not generated live on this page.

Anime Character
A fierce warrior princess with flowing silver hair and golden armor, standing atop a cliff overlooking a vast battlefield, anime art style, dramatic wind effects, detailed cel shading
Cozy Interior
A hygge-inspired reading nook with floor-to-ceiling bookshelves, a plush velvet armchair, warm fairy lights, a sleeping cat, and rain visible through a large arched window, digital painting style
Abstract Art
Geometric crystalline formations emerging from a pool of liquid gold, refracting rainbow light prisms throughout the composition, ultra-detailed 3D render with volumetric lighting and caustics

About Stable Diffusion XL

TL;DRAs of September 23, 2026

Stable Diffusion XL is a model by Stability AI in the Image generation category. On Railwail, Stable Diffusion XL costs ≈ $0.0015 per run.

Background

About Stability AI

Founded 2019 · London, UK

Stability AI was founded in 2019 by Emad Mostaque (CEO until March 2024) and is headquartered in London. The company sponsored and released the original Stable Diffusion 1.4/1.5/2.x (2022) in partnership with CompVis (LMU Munich, Robin Rombach and Patrick Esser), Runway and LAION. Stable Diffusion XL (SDXL) was released in July 2023 by Stability AI as a successor to SD 1.5/2.1 and was widely adopted by the open-source community as the de-facto open base model for fine-tuning and downstream pipelines until FLUX.1 and SD 3.5 arrived in 2024.

Visit Stability AI

Architecture

Latent diffusion U-Net with two text encoders and optional refiner

Stable Diffusion XL (SDXL) is a 2023 latent diffusion model from Stability AI, described in 'SDXL: Improving Latent Diffusion Models for High-Resolution Image Synthesis' (Podell et al. 2023). The architecture is a refined latent-diffusion U-Net operating in the latent space of a learned 8x VAE. Key changes over SD 1.5 include: (1) a larger U-Net backbone (~3.5B parameters, ~3x larger than SD 1.5), (2) two parallel text encoders concatenating CLIP ViT-L and OpenCLIP ViT-bigG features for stronger prompt adherence, (3) conditioning on the original image resolution and crop coordinates to fix the resolution and cropping artefacts of SD 1.5, (4) training natively at 1024x1024 instead of 512x512, and (5) an optional 6.6B-parameter refiner model that performs a final 5-step denoising pass to add high-frequency detail. SDXL became the dominant open base model for fine-tuning between mid-2023 and late 2024, spawning huge ecosystems including IP-Adapter, AnimateDiff, ControlNet-XL, T2I-Adapter and tens of thousands of community LoRAs.

Parameters: ~3.5B base U-Net + 6.6B refiner = ~10.1B total
Context: 75 tokens

Capabilities

Native 1024x1024 generation
Two text encoders (CLIP-L + OpenCLIP-G) for strong prompts
Optional refiner for high-frequency detail
Open weights under CreativeML Open RAIL++-M license
Massive ecosystem: ControlNet-XL, IP-Adapter, AnimateDiff, LoRAs
Strong fine-tuning base for art styles and brand models
Runs on consumer GPUs (8-12GB VRAM with quantisation)
Best for: fine-tuning base, ControlNet pipelines, community LoRAs, on-prem deployments, education.

Training & license

Pretrained on a large subset of LAION-5B and additional Stability AI-curated data. Conditioned on resolution and crop coordinates to mitigate aspect-ratio artefacts.

License: CreativeML Open RAIL++-M license — open weights with usage restrictions (no NCII, CSAM, etc.). Commercial use permitted with these restrictions.

Safety testing: Stability AI applied baseline content filters and training data filtering. The model ships without an integrated safety classifier and operators must add their own moderation.

Known limitations

Older architecture — outperformed by FLUX.1 and SD 3.5 Large
Hands, text and complex anatomy imperfect
Default text encoder limited to 75 tokens
Open weights have no built-in safety filter

Research papers

Pricing

Prices in US dollars. Usage is charged from prepaid credits.

Typical run (≈ 1 s on L40S)	$0.0015 per run
GPU time (L40S)	$0.00117 per GPU second

Billed by the GPU time the run actually takes. When the run starts, 3× the typical price is reserved from your balance and settled afterwards.
1 credit = $0.01

Cost calculator

Price calculator

GPU seconds per run

Typical according to the provider: about 1.2 s

Runs

Total

$0.15

15 credits

Per run

$0.0015 · 0.15 credits

Billed by the actual GPU time; this is an estimate.

API

Call Stable Diffusion XL with your Railwail API key. Use this model ID in the request:

stable-diffusion-xlAPI documentation Get an API key

curl https://railwail.com/api/v1/images/generations \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "stable-diffusion-xl",
    "prompt": "A lighthouse on a rocky coast at sunset, photorealistic"
  }'

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["RAILWAIL_API_KEY"],
    base_url="https://railwail.com/api/v1",
)

image = client.images.generate(
    model="stable-diffusion-xl",
    prompt="A lighthouse on a rocky coast at sunset, photorealistic",
)

print(image.data[0].url)

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.RAILWAIL_API_KEY,
  baseURL: "https://railwail.com/api/v1",
});

const image = await client.images.generate({
  model: "stable-diffusion-xl",
  prompt: "A lighthouse on a rocky coast at sunset, photorealistic"
});

console.log(image.data[0].url);

// npm install railwail
import railwail from "railwail";

const rw = railwail(process.env.RAILWAIL_API_KEY);

const res = await rw.image("stable-diffusion-xl", "A lighthouse on a rocky coast at sunset, photorealistic");

console.log(res.data[0].url);

Set your key as RAILWAIL_API_KEYCreate API key

Specifications

Model ID: stable-diffusion-xl
Developer: Stability AI
Category: Image generation
Input: Text
Output: Image
Output formats: WEBP, JPG, PNG
Billing: By usage (tokens or GPU time)
Model size: ~3.5B base U-Net + 6.6B refiner = ~10.1B total
License: CreativeML Open RAIL++-M license — open weights with usage restrictions (no NCII, CSAM, etc.). Commercial use permitted with these restrictions.
Catalog entry updated: September 23, 2026

Input parameters

Inputs and settings from the model's input schema. The example in the API section shows which of them the API accepts.

ParameterTypeDefaultAllowed values

promptrequired
Type: Text
Default: –
Allowed values: –
width
Type: Choice
Default: 1024
Allowed values: 512, 768, or 1024
height
Type: Choice
Default: 1024
Allowed values: 512, 768, or 1024
negative_prompt
Type: Text
Default: –
Allowed values: –

Use cases

What it is used for

Open-source creative pipelines (legacy)
Fine-tuning base for art-style models
ControlNet and IP-Adapter workflows
Community LoRA training
On-prem and air-gapped deployments
Educational and research use

All models in Image generation

Frequently asked questions

What is Stable Diffusion XL?

Stable Diffusion XL is a model by Stability AI in the Image generation category. On Railwail you can call it with an API key through the Railwail API.

How much does Stable Diffusion XL cost on Railwail?

On Railwail, Stable Diffusion XL costs ≈ $0.0015 per run. You are charged for what each request actually uses. Usage is paid from prepaid credits; 1 credit equals $0.01.

Which settings does Stable Diffusion XL support?

According to its input schema, Stable Diffusion XL knows these parameters: prompt, width (512, 768, or 1024), height (512, 768, or 1024), and negative_prompt.

How fast is Stable Diffusion XL?

There are not enough measured runs of Stable Diffusion XL on Railwail yet to state a run time. It depends on the input, the settings and the load at the provider.

Is Stable Diffusion XL better than FLUX 1.1 Pro?

That depends on the task. Stable Diffusion XL (Stability AI) and FLUX 1.1 Pro (Black Forest Labs) are both models in the Image generation category. The comparison page shows their prices and specifications side by side.

Compare Stable Diffusion XL and FLUX 1.1 Pro

How do I use Stable Diffusion XL through the API?

Create a Railwail API key and send your request with the model ID stable-diffusion-xl. Code examples for curl, Python and JavaScript are in the API section of this page.

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Use Stable Diffusion XL via the API

One API key for every model on Railwail. Usage is charged from prepaid credits, 1 credit = $0.01.

Get API key Browse all models