Background Removal (Binary)#

Remove the background and return an RGBA PNG cutout.

Cost: 1 credit on HTTP 200.

Best for servers, CLIs, and batch pipelines that want raw PNG bytes (no JSON/base64 overhead). For a full-resolution compositing workflow, prefer the alpha-matte endpoints.

Set shadow_if_possible to add a cast shadow under a subject that stands on the ground; X-Shadow reports whether one was added.

Binary sibling of /v1.0/image-without-background-base64. Response metadata is returned in X-Input-Dimensions, X-Processed-Dimensions, X-Was-Downscaled, and optional X-Image-Type-* headers.

Endpoint#

POST /v1.0/image-without-background

Base URL: https://api.withoutbg.com · Spec: openapi.json

Example (cURL)#

cURL

curl -X POST \
  -H "X-API-Key: $WITHOUTBG_API_KEY" \
  -F "file=@/path/to/input.jpg" \
  --output result.png \
  "https://api.withoutbg.com/v1.0/image-without-background"

Authentication#

Provide your API key in the request header:

API key header

X-API-Key: <your_api_key>

Request#

Content-Type: multipart/form-data

Fields#

  • file (string, required)
  • include_image_type (boolean, optional) · default true — When true (default), include photo vs graphic probabilities in X-Image-Type-* headers. Set false to skip.
  • keep_mask (string, optional) — Optional Keep mask: marked pixels become fully opaque. One stroke on a person or object that was cut away brings back all of it. It is an image with the same width and height as the input (after EXIF orientation) or as the returned matte (processed_dimensions). White (light, opaque) pixels mark the area; black or transparent pixels mark nothing, so paint white strokes on a black or transparent canvas. The image is matted, then the strokes edit that matte: a rough stroke is enough, then edges are refined again. To fix a result further, send all strokes so far again. Where keep_mask and remove_mask overlap, Remove wins. Maximum size: 5.0 MB.
  • remove_mask (string, optional) — Optional Remove mask: marked pixels become fully transparent. One stroke on an extra person or object removes all of it. It is an image with the same width and height as the input (after EXIF orientation) or as the returned matte (processed_dimensions). White (light, opaque) pixels mark the area; black or transparent pixels mark nothing, so paint white strokes on a black or transparent canvas. The image is matted, then the strokes edit that matte: a rough stroke is enough, then edges are refined again. To fix a result further, send all strokes so far again. Where keep_mask and remove_mask overlap, Remove wins. Maximum size: 5.0 MB.
  • shadow_if_possible (boolean, optional) · default false — When true, add a soft cast shadow under the subject if it stands on the ground. A ground-contact check runs first: floating, flying or jumping subjects, and ones where ground contact is uncertain, get no shadow, and neither does a photo whose camera or ground can't be recovered. The shadow is baked into the RGBA cutout behind the subject, with its light fitted to the shadow already in the photo (a default light when there is none). Vehicles always get their cast shadow, with or without this flag. Ignored when a Keep / Remove mask is sent. Default false. Same cost: 1 credit.

Response#

Success Content-Type: image/png

Response headers#

  • X-Input-Dimensions — Decoded input size as `width,height` (pixels).
  • X-Processed-Dimensions — Size after server prep downscale (longest side / megapixel caps) as `width,height`. Not the model inference resolution (~1024 long side).
  • X-Was-Downscaled — Whether the input was downscaled during server prep (`true`/`false`).
  • X-Image-Type-Photo — Optional photo-class probability from image-type classifier.
  • X-Image-Type-Graphic — Optional graphic-class probability from image-type classifier.
  • X-Shadow — Sent when `shadow_if_possible` is true: `true` if a cast shadow was added under the subject, `false` if not (subject off the ground, or no ground could be recovered).

Errors#

StatusDescriptionDetail
401Invalid API KeyInvalid API Key
402Insufficient credit. Please top up API credits.Insufficient credit. Please top up API credits.
403Credits Expired. Please top up API credits. If you have existing credits, they will be reactivated.Credits Expired. Please top up API credits. If you have existing credits, they will be reactivated.
413File size too large. Maximum file size is 20.0 MB.File size too large. Maximum file size is 20.0 MB
415Unsupported Media Type. Supported formats are: JPEG, PNG, WebP, AVIF, HEIC, TIFF, BMP, GIF.Unsupported Media Type. Supported formats are: JPEG, PNG, WebP, AVIF, HEIC, TIFF, BMP, GIF.
422Validation ErrorValidation Error
429Rate limit exceeded (product policy: 30 requests/minute per API key). May be returned by the API gateway. Retry with exponential backoff.{"error":"Too Many Requests","status":429,"message":"Rate limit exceeded. Please try again later"}
500Internal Server ErrorInternal Server Error. Please contact support: contact@withoutbg.com

Contract sections are generated at build time from OpenAPI. Markdown mirror: /docs/pro-model/background-removal-binary.md