Which FLUX models does the ModelsLab FLUX API support?

ModelsLab serves the full FLUX.1 family through one endpoint: FLUX.1 Schnell for the fastest, lowest-latency generations, FLUX.1 Dev for higher-quality output, FLUX.1 Pro for the best fidelity, and FLUX.1 Kontext for prompt-based image editing. You switch between them with a single model_id parameter — no separate integrations.

How much does the FLUX API cost?

FLUX image generation is a flat $0.0047 per image on pay-as-you-go — the same price across every FLUX variant, with no resolution upcharge up to 2048×2048. High-volume teams use the $199/month Open Source Unlimited plan for unlimited generation, and dedicated enterprise endpoints start at $249/month. Pricing verified July 2026.

How do I call the FLUX API?

Send a POST request to https://modelslab.com/api/v7/images/text-to-image with your API key, model_id set to "flux" (or a specific variant), and a prompt. The response returns hosted image URLs in JSON within 2-4 seconds. Python, JavaScript, and cURL examples are documented at docs.modelslab.com.

Does the FLUX API support LoRA and custom fine-tunes?

Yes. You can attach FLUX LoRAs to steer style, and you can train and deploy your own FLUX LoRAs through the API. Custom LoRAs run through the same text-to-image endpoint by referencing them in the request, so branded or subject-specific pipelines work without extra infrastructure.

Can I edit images with FLUX.1 Kontext through the API?

Yes. FLUX.1 Kontext is an image-editing model: send an input image plus an instruction prompt and it applies the edit while preserving the rest of the scene. It is available through the same ModelsLab image API, so text-to-image generation and Kontext-based editing share one API key.

Is there a free way to test the FLUX API?

Yes. Create a ModelsLab API key without a credit card and test FLUX.1 Schnell, Dev, Pro, and Kontext on the free tier before choosing a plan. Paid plans start at $21/month (Basic) and $47/month (Standard) for production volume.

Imagen

Flux API for Developers

ModelsLab's Flux API gives developers FLUX.1 Schnell, Dev, Pro, and Kontext through a single REST endpoint. Image generation is a flat $0.0047 per image — no per-variant surcharge — with 2-4 second latency and a free API key. Attach LoRAs, edit images with Kontext, and scale to unlimited generation on the $199/month plan.

Get Your Flux API Key API Documentation

What is the ModelsLab Flux API?

FLUX.1 Image Generation, One REST Endpoint

The ModelsLab Flux API gives developers programmatic access to the full FLUX.1 model family — Schnell, Dev, Pro, and Kontext — through a single REST endpoint. Instead of wiring up separate integrations for each variant, you pass a model_id and a prompt to /api/v7/images/text-to-image and receive hosted image URLs in JSON within 2-4 seconds.

FLUX.1, from Black Forest Labs, is a state-of-the-art rectified-flow transformer known for sharp detail, strong prompt adherence, and legible in-image text. ModelsLab hosts every variant so you can trade speed for quality with a one-line change: Schnell for fast drafts, Dev for high-quality output, Pro for the best fidelity, and Kontext for instruction-based image editing.

Because ModelsLab manages GPU allocation, model loading, auto-scaling, and warm instances, there are no cold starts on popular FLUX models — your first request is as fast as your hundredth. The same API key also covers 10,000+ other image, video, audio, and LLM models when your product grows beyond FLUX.

What You Can Build with the Flux API

The Flux API supports the full range of FLUX image workflows through one key:

Text-to-Image — Generate images from natural-language prompts with FLUX.1 Schnell, Dev, or Pro at up to 2048×2048
Image Editing — Apply instruction-based edits to an existing image with FLUX.1 Kontext while preserving the rest of the scene
LoRA Styling — Attach FLUX LoRAs to steer style, or train and deploy your own for branded and subject-specific pipelines
Batch Generation — Request multiple samples per call for A/B testing and variation exploration
Async + Webhooks — Fire-and-forget generation with webhook callbacks for high-volume pipelines

Trusted by

1B+

Images Processed Monthly

500K+

Active Developers

5K+

Discord Community Members

300+

Available AI APIs

FLUX.1 Model Variants

One endpoint, every FLUX.1 variant. Switch with a single model_id — pricing stays a flat $0.0047 per image across all of them.

Variant	Best for	Speed	ModelsLab price
flux (Schnell)	Fast drafts, real-time previews, high-volume generation	2-3s	$0.0047/image
flux-dev	High-quality production images with strong prompt adherence	3-5s	$0.0047/image
flux-pro	Best fidelity and detail for hero and marketing assets	4-6s	$0.0047/image
flux-kontext	Instruction-based image editing from a reference image	3-5s	$0.0047/image

Flux API Quick Start

Generate a FLUX image in seconds with a single REST call — cURL, Python, or JavaScript.

Generate a FLUX image with cURL

curl

1curl -X POST "https://modelslab.com/api/v7/images/text-to-image" \
2  -H "Content-Type: application/json" \
3  -d '{
4    "key": "YOUR_API_KEY",
5    "model_id": "flux",
6    "prompt": "a neon-lit ramen bar in the rain, cinematic, 35mm",
7    "width": 1024,
8    "height": 1024,
9    "samples": 1,
10    "num_inference_steps": 4
11  }'

Generate with Python

Python

1import requests
2
3url = "https://modelslab.com/api/v7/images/text-to-image"
4payload = {
5    "key": "YOUR_API_KEY",
6    "model_id": "flux-dev",
7    "prompt": "product photo of a matte black watch on concrete, studio lighting",
8    "negative_prompt": "blurry, low quality",
9    "width": 1024,
10    "height": 1024,
11    "samples": 2,
12    "num_inference_steps": 28,
13    "guidance_scale": 3.5
14}
15
16response = requests.post(url, json=payload)
17data = response.json()
18
19# data["output"] is a list of generated FLUX image URLs
20for i, image_url in enumerate(data["output"]):
21    print(f"Image {i+1}: {image_url}")

Edit an image with FLUX.1 Kontext (JavaScript)

JavaScript

1const response = await fetch('https://modelslab.com/api/v7/images/image-to-image', {
2  method: 'POST',
3  headers: { 'Content-Type': 'application/json' },
4  body: JSON.stringify({
5    key: 'YOUR_API_KEY',
6    model_id: 'flux-kontext',
7    init_image: 'https://example.com/room.jpg',
8    prompt: 'change the sofa to emerald green velvet',
9    samples: 1
10  })
11});
12
13const data = await response.json();
14// data.output = array of edited image URLs
15data.output.forEach((url, i) => console.log(`Result ${i + 1}: ${url}`));

One Flux API, Every Variant Plus LoRAs

Text-to-image, image editing with Kontext, and custom LoRA fine-tunes — all behind a single FLUX endpoint and one API key.

Every FLUX.1 Variant

Schnell, Dev, Pro, and Kontext are all available through the same text-to-image and image-to-image endpoints. Switch model_id to trade speed for fidelity without touching the rest of your integration.

FLUX LoRA Fine-Tuning

Attach existing FLUX LoRAs to steer style, or train and deploy your own. Custom LoRAs run through the standard endpoint by referencing them in the request — ideal for consistent brand or character styling.

Kontext Image Editing

FLUX.1 Kontext takes an input image plus an instruction prompt and applies the edit while preserving the rest of the scene. Product recolors, background swaps, and targeted changes all run through the API.

Predictable Flat Pricing

Every FLUX variant costs a flat $0.0047 per image — no per-megapixel math and no premium for Pro. High-volume teams cap spend entirely with the $199/month unlimited plan.

Everything developers need to ship FLUX-powered image features in production.

Start Free Trial

FLUX API Provider Comparison

How ModelsLab compares to other ways to access FLUX.1 models.

Feature	ModelsLab	fal.ai	Replicate	Black Forest Labs
FLUX.1 variants	Schnell, Dev, Pro, Kontext	Schnell, Dev, Pro	Schnell, Dev, Pro	Pro, Ultra (official)
Other models on same key	10,000+	~50	Thousands (self-serve)	FLUX only
FLUX LoRA support	Attach + train	Attach	Attach + train	No
Image editing (Kontext)	Yes	Yes	Yes	Yes
Cold starts	None (warm)	Occasional	Frequent	None
Flat per-image price	$0.0047/image	Per-megapixel, varies by variant	Per-second + per-image	Per-image by tier
Unlimited plan	$199/mo	No	No	No
Free API key (no card)	Yes	Trial credits	Trial credits	No

Data as of July 2026. Competitor pricing based on publicly published per-image and per-megapixel rates for FLUX.1 variants; verify current rates before comparing for your workload.

Related image API guides

Image Generation API

Full catalog: FLUX, SDXL, SD 3.5, and 10,000+ models through one endpoint.

Stable Diffusion API

SDXL, SD 3.5, ControlNet, and LoRA via the same REST API and key.

Cheapest AI Image API

Flat $0.0047/image and the $199 unlimited plan compared across providers.

How to Use the Flux API

Generate your first FLUX image in under 5 minutes.

STEP 01

Step 1: Get Your API Key

Create a free ModelsLab account and generate your API key. No credit card required — the free tier includes credits to test every FLUX variant.

STEP 02

Step 2: Pick a Variant and Prompt

Send a POST request to /api/v7/images/text-to-image with model_id set to flux, flux-dev, or flux-pro, plus your prompt and generation parameters like width, height, and steps.

STEP 03

Step 3: Get Your Images

Receive hosted image URLs in the JSON response within 2-4 seconds. Use flux-kontext with an init_image to edit images instead of generating from scratch.

Start Generating with Flux

Flux API Pricing

The Flux API uses simple, flat pricing: $0.0047 per image on pay-as-you-go, the same across FLUX.1 Schnell, Dev, Pro, and Kontext with no resolution upcharge up to 2048×2048. That is roughly 8.5x cheaper than OpenAI DALL-E 3 at $0.040 per image, and undercuts the Stability AI API on comparable generation.

Against fal.ai and Replicate, ModelsLab is competitive on their cheapest FLUX variants and becomes the cheapest option at scale: the $199/month Open Source Unlimited plan removes per-image cost entirely for high-volume generation. Paid plans start at $21/month (Basic) and $47/month (Standard), and dedicated enterprise endpoints with custom SLAs start at $249/month. A free tier lets you evaluate before committing.

API Response Format

The Flux API returns a consistent JSON response. Generated images come back as publicly accessible URLs (available for 24 hours) or as base64 data for direct embedding. Synchronous requests return images in the response; for longer or batched jobs, use asynchronous mode and poll the fetch endpoint with the returned request_id, or register a webhook to receive completions.

Integration and SDKs

ModelsLab provides SDKs and integration paths for the Flux API across popular stacks:

Python SDK — pip install modelslab — full endpoint coverage with async support
JavaScript/TypeScript — npm install modelslab — works in Node.js, Deno, and the browser
REST API — standard HTTP endpoints usable from any language (cURL, Go, Ruby, PHP, Java)
Webhook callbacks — receive FLUX completion notifications for async pipelines
Documentation — per-parameter guides and examples at docs.modelslab.com

Why ModelsLab for the Flux API?

Key advantages that set us apart

Every FLUX.1 variant — Schnell, Dev, Pro, Kontext — on one endpoint

Flat $0.0047 per image with no per-variant surcharge

$199/mo unlimited plan for high-volume FLUX generation

Attach FLUX LoRAs or train and deploy your own

Kontext image editing through the same API key

No cold starts on popular FLUX models

Up to 2048×2048 native generation, no resolution upcharge

2-4 second latency with async + webhook support

10,000+ other image, video, audio, and LLM models on the same key

Free API key with no credit card to evaluate

Our Popular Use Cases

What developers build with the Flux API:

Embed FLUX text-to-image and Kontext editing directly into design apps, letting users generate and refine high-fidelity visuals on demand.

Flux API FAQ

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AI Image API Pricing Starting at $0.0047 Per Image

ModelsLab offers subscription plans from $21/month (Basic) and $47/month (Standard, 10,000 API calls) to $199/month (Open Source Unlimited). All plans include access to Flux, SDXL, Stable Diffusion 3, and 10,000+ community models. Start free, cancel anytime, 100% refund policy.