851 Labs

851 Labs Background Remover

851-labs/background-remover

An image processing model focused on automatic cutout, capable of outputting transparent PNGs or masks, suitable for batch background removal from e-commerce product photos and portraits

851-labs/background-remover

Try 851-labs/background-remover

Input

Showcases

View all showcases

Output

image

Fill in the parameters and run — results show up here.

Pricing

851-labs/background-remover per image

Unit Price	$0.002

Positioning Overview

background-remover is a single-task image background removal model offered by 851 Labs and accessed through the unified HiAPI.ai interface. Developers submit a publicly accessible image URL and receive a background-removed result, making it suitable for automated workflows that require low-cost, fast cutout processing, such as preprocessing for e-commerce assets, avatars, and content imagery. It does not handle generation or editing; its purpose is to do the single step of cleanly separating foreground from background reliably.

Key Highlights

Lightweight cutout focused on a single task — it only performs background removal with no extra parameters, keeping integration costs low and making it suitable for embedding into existing image processing pipelines.
Direct URL input, one request per image — the input requires only an image address, and the simple call structure makes it easy to integrate into batch jobs and asynchronous queues.
Low-cost batch processing — billing is per image, making it suitable for asset cleanup scenarios that require large volumes of repeated cutouts.

Capability Description

Automatic background removal: performs foreground separation on the input image and directly returns the background-removed image result, eliminating manual outlining and mask adjustments.

Remote image URL input: supports a publicly accessible image address starting with http or https as the only input, with no need to upload files first, making it easy to connect with existing image hosting and asset libraries.

Single-image output, easy to chain: each call produces one processed image, which can be directly integrated as an intermediate asset in subsequent composition, layout, or listing workflows.

Use Cases

E-commerce operations: product image background removal — process original product images into clean foreground assets for listings with a unified background color or for ad image layout.
Content creators: portrait and avatar cutouts — remove backgrounds from portrait photos to produce transparent assets that can be used directly in stickers, social media images, and personal profile pages.
Design workflows: asset preprocessing — process images into background-removed layers before design layout to reduce manual cutout time, as a standardized step for asset ingestion.
Platform operations: batch asset cleanup — submit images already hosted at URLs in the image hosting service for batch processing and uniformly obtain background-removed versions for product or content display.

Limitations and Selection Advice

The capability is limited to background removal and does not include image generation, inpainting, or complex editing; when creative image modification is needed, other image models should be selected. Output quality is affected by the input image; images where the subject and background colors are similar or edge details are complex may require manual review. Calls require a publicly accessible image URL, and files on local or private networks must first be hosted at an accessible location. If the task is primarily not cutout, it is recommended to use a model with generation or editing capabilities instead.

Frequently asked questions

View all FAQs →

Do I need a prompt?

No. Supply one image URL and the model separates the foreground from the background.
Is the output actually transparent?

The output is a PNG with an alpha channel. The checkerboard on this page illustrates transparency and is not embedded in the original downloadable result.
Which fields does the API require?

Submit model and input.image_url. The image must be directly accessible over HTTP or HTTPS.
Can I change the aspect ratio, colors or background?

This endpoint focuses on background removal and offers no aspect-ratio, background-color or prompt controls. Use the transparent output in a subsequent editing step.

Create a generation task

POST https://api.hiapi.ai/v1/tasks

Headers

AuthorizationstringRequired

Account API key. Required on every request. Example: Bearer YOUR_HIAPI_API_KEY. Get your API key

Content-TypestringOptional

The request body is always parsed as JSON; when sent, only application/json (optionally with charset) is accepted — any other value returns 415. Example: application/json.

Idempotency-KeystringOptional

Idempotency key, up to 255 bytes. Retries with the same key from the same account create the task only once; replays return the original taskId.

Idempotency key

On network timeouts or client retries, the same key creates the task only once — no double charges (scope: the API key's account). Use a business-unique identifier as the key (e.g. "order-42"); replays return the original taskId, and keys expire 24 hours after the first request. See the Unified Async API overview for the full scenario matrix.

Body

modelstringRequired

Current fixed value: 851-labs/background-remover

routestringOptional

Current fixed value: default

inputobjectRequired

Business parameters for 851-labs/background-remover and route default — see the parameter table below.

image_urlstringRequiredminLength 1pattern ^https?://[^\s]+$

The URL of the image to be processed, which must be a publicly accessible image URL. This parameter is the input source for background removal; once provided, the service will fetch the image and return the result with the background removed.

callbackobjectOptional

Terminal-state notification config. When omitted, no callback is delivered — poll the task yourself. See the callback note below.

Callbacks (Webhook)

Provide callback.url when creating a task and HiAPI POSTs to your service once the task reaches a terminal state — no polling needed. The callback payload mirrors the task detail structure; signature verification, delivery retries and idempotency are documented on the Unified Async API overview page.

urlstringRequired

Required when callback is present. A POST is sent to this URL once the task reaches a terminal state; must be a valid http(s) URL.

whenstringOptionalDefault: "final"

Only final is supported today — notified on both success and fail.

Options:final

storagestringOptionalDefault: "temp"

Artifact storage tier: temp (default, retained about 7 days) or persistent (long-term, billed by size). Insufficient balance or exceeding the storage cap silently downgrades to temp; the effective tier is shown in the task detail response.

Options:temppersistent

Request examples

# Submit an async task; returns a taskId immediately (no waiting for generation)
curl -X POST "https://api.hiapi.ai/v1/tasks" \
  -H "Authorization: Bearer $HIAPI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "851-labs/background-remover",
  "input": {
    "image_url": "…"
  }
}'

const res = await fetch("https://api.hiapi.ai/v1/tasks", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.HIAPI_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    model: "851-labs/background-remover",
    input: {
      "image_url": "…"
    }
  }),
});
const task = await res.json();
// { code: 200, message: "success", data: { taskId } }

import os, requests

res = requests.post(
    "https://api.hiapi.ai/v1/tasks",
    headers={"Authorization": f"Bearer {os.environ['HIAPI_API_KEY']}"},
    json={
        "model": "851-labs/background-remover",
        "input": {
          "image_url": "…"
        }
    },
)
print(res.json())  # { code, message, data: { taskId } }

200 OK

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "tk-hiapi-01HZTQ8BX2N3GM3YFK4Z9D7VQR"
  }
}

400 Bad Request

{
  "code": 400,
  "message": "invalid request",
  "data": null,
  "error_code": "INVALID_REQUEST"
}

Get task detail

GET https://api.hiapi.ai/v1/tasks/:id

Response fields

taskIdstringRequired

Task ID, always prefixed with tk-hiapi-.

modelstringRequired

Resolved full model name. Tasks submitted with the route parameter return base@route (e.g. gpt-image-2/text-to-image@ext); otherwise identical to the name passed at creation.

routestringOptional

Present only when the task was submitted with an explicit route parameter; echoes the submitted value.

statusstringRequired

Task status.

Status values

queued Queued, not started yet. handling Being processed. archiving Processing finished, artifacts being prepared. success Terminal: completed, artifacts available (output returned). fail Terminal: failed (error returned). After submission, check status: success and fail are terminal, everything else is non-terminal. Poll every 1–3 seconds until terminal. On success, download artifacts from output[].url and transfer them before expireAt; pass storage: "persistent" at creation time when long-term retention is needed.

creatednumberRequired

Task creation time (Unix seconds).

completednumberRequired

Unix seconds when the task reached a terminal state; fixed to 0 while not terminal.

outputarrayOptional

Present only when status == success. Artifact list — always an array; a single task may return multiple types at once (e.g. video + first_frame).

Array [ object ]

Array items

urlstringRequired

Artifact URL, directly downloadable.

typestringRequired

Current possible values: video, image, audio, first_frame, last_frame, thumbnail; more may be added later.

expireAtnumberRequired

Unix seconds until which the artifact remains accessible; download or transfer before it expires.

errorobjectOptional

Present only when status == fail.

codestringRequired

Business error code.

messagestringRequired

Error description.

Response examples

Success

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "tk-hiapi-01HZTQ8BX2N3GM3YFK4Z9D7VQR",
    "model": "happyhorse-1-0",
    "status": "success",
    "created": 1777282033,
    "completed": 1777282099,
    "output": [
      {
        "url": "https://cdn.hiapi.ai/tasks/.../video.mp4",
        "type": "video",
        "expireAt": 1777886899
      }
    ]
  }
}

Processing (non-terminal)

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "tk-hiapi-...",
    "model": "happyhorse-1-0",
    "status": "archiving",
    "created": 1777282033,
    "completed": 0
  }
}

Failed

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "tk-hiapi-...",
    "model": "happyhorse-1-0",
    "status": "fail",
    "created": 1777282033,
    "completed": 1777282099,
    "error": {
      "code": "TASK_FAILED",
      "message": "task failed"
    }
  }
}