Image

Flux Fill Pro API

Black Forest Labs' image-editing model from the Flux.1 Tools suite (Nov 2024), a state-of-the-art inpainting and outpainting model that edits and extends existing images rather than generating them from scratch.

Get API key Read the docs

~19s
Avg. generation: 6 credits
From

Flux 2 Max marketplace-ready product photo of a ceramic pour-over coffee set on a clean white surface in soft studio lighting — A polished photo of a ceramic pour-over coffee set on a clean white surface, soft studio lighting, sharp detail.

Playground

Try Flux Fill Pro right here.

model: flux-fill-pro

Prompt

Mode

Outpaint preset

Media inputs

Source image Mask

Advanced settings

Prompt upsampling Steps Guidance Safety tolerance Output format Seed

Estimated cost 6 credits · $0.06 Generate in Studio

Output Example · Flux 2 Max

Pricing

Simple per-generation pricing.

6 credits per generation ≈ $0.06

You only pay for successful generations. Failed jobs are refunded automatically.
One credit balance across every model on Apiframe, no per-model plans.
Start with free credits. No subscription required.
Volume discounts on larger plans.

See plans and credit packs

Specs

At a glance.

Provider Black Forest Labs

Model ID flux-fill-pro

Image input Supported

Avg. time ~19s

Quickstart

How to call the Flux Fill Pro API.

Send one POST /v2/images/edit request with your API key. The call returns a jobId you can poll, or pass a webhook_url and the result is pushed to you the moment it's ready.

Swap flux-fill-pro for any other model and nothing else changes.

Get API key Read the docs

generate.js

const response = await fetch("https://api.apiframe.ai/v2/images/edit", {
  method: "POST",
  headers: {
    "X-API-Key": "afk_your_api_key_here",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "prompt": "a sleek silver sports car on a coastal highway at sunset, hyper-realistic",
    "model": "flux-fill-pro",
    "fluxFillParams": {
      "image": "https://example.com/input.jpg",
      "mode": "inpaint",
      "mask": "https://example.com/input.jpg",
      "outpaint": "Zoom out 1.5x"
    }
  }),
});
const { jobId } = await response.json();
console.log(jobId);

import requests

response = requests.post(
    "https://api.apiframe.ai/v2/images/edit",
    headers={
        "X-API-Key": "afk_your_api_key_here",
        "Content-Type": "application/json",
    },
    json={
        "prompt": "a sleek silver sports car on a coastal highway at sunset, hyper-realistic",
        "model": "flux-fill-pro",
        "fluxFillParams": {
            "image": "https://example.com/input.jpg",
            "mode": "inpaint",
            "mask": "https://example.com/input.jpg",
            "outpaint": "Zoom out 1.5x"
        }
    },
)
print(response.json())  # { "jobId": "...", "status": "QUEUED" }

curl -X POST https://api.apiframe.ai/v2/images/edit \
  -H "X-API-Key: afk_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
        "prompt": "a sleek silver sports car on a coastal highway at sunset, hyper-realistic",
        "model": "flux-fill-pro",
        "fluxFillParams": {
            "image": "https://example.com/input.jpg",
            "mode": "inpaint",
            "mask": "https://example.com/input.jpg",
            "outpaint": "Zoom out 1.5x"
        }
    }'

let job;
do {
  await new Promise((r) => setTimeout(r, 2000));
  job = await fetch("https://api.apiframe.ai/v2/jobs/JOB_ID", {
    headers: { "X-API-Key": "afk_your_api_key_here" },
  }).then((r) => r.json());
} while (job.status !== "COMPLETED" && job.status !== "FAILED");
console.log(job.result);

import requests, time

while True:
    job = requests.get(
        "https://api.apiframe.ai/v2/jobs/JOB_ID",
        headers={"X-API-Key": "afk_your_api_key_here"},
    ).json()
    if job["status"] in ("COMPLETED", "FAILED"):
        break
    time.sleep(2)
print(job["result"])

curl https://api.apiframe.ai/v2/jobs/JOB_ID \
  -H "X-API-Key: afk_your_api_key_here"

Input schema

Every field Flux Fill Pro accepts, with types and defaults. The full reference lives in the docs.

Field	Type	Description
prompt required	string	Text description of what to generate.
model required	string	The model identifier for this endpoint. Default:"flux-fill-pro" · "flux-fill-pro"
fluxFillParams.image	string (URL)	Source image (URL)
fluxFillParams.mode	string	Mode Default:"inpaint" · "inpaint", "outpaint"
fluxFillParams.mask	string (URL)	White = repaint, black = keep. Required for inpaint.
fluxFillParams.outpaint	string	Required for outpaint mode. Default:"Zoom out 1.5x" · "Zoom out 1.5x", "Zoom out 2x", "Make square", "Left outpaint", "Right outpaint", "Top outpaint", "Bottom outpaint"
fluxFillParams.prompt	string	Prompt
fluxFillParams.prompt_upsampling	boolean	Prompt upsampling Default:false
fluxFillParams.steps	number	Steps Default:50 · min 1, max 50, step 1
fluxFillParams.guidance	number	Guidance Default:3 · min 2, max 5, step 0.1
fluxFillParams.safety_tolerance	number	1 = strictest, 6 = most permissive. Default:2 · min 1, max 6, step 1
fluxFillParams.output_format	string	Output format Default:"jpg" · "jpg", "png"
fluxFillParams.seed	number	Reuse a number to reproduce the same result. step 1

The Flux flagship

Flux Fill Pro is one of 7 Flux image models on Apiframe. The full editorial page (showcase, comparison, and use cases) lives on the flagship.

Flagship from 7 cr Flux 2 Max

The quality ceiling of the Flux family.

Explore Flux 2 Max All image models

Flux Fill Pro questions

What teams ask before shipping with Flux Fill Pro. Everything else lives in the docs.

What does Flux Fill Pro actually do?

It handles inpainting and outpainting, meaning it edits masked areas inside an image and extends images beyond their original borders.

What is the difference between inpainting and outpainting?

Inpainting fills or changes a region inside the image, while outpainting adds new content outward past the edges.

Does it work on real photos or only AI images?

Both. It edits and extends real and AI-generated images alike.

How is Fill Pro different from Fill Dev?

Pro is the commercial, API-hosted model built for maximum performance, while Dev is the open-access, non-commercial variant with downloadable weights.

Do you need a mask to use it?

For inpainting, yes, a mask marks the area to edit alongside your text prompt. Outpainting extends the canvas instead.

Where can you access it?

Through Apiframe, as well as the BFL API and major hosting partners.