LassoCut: remove image backgrounds with curl
The LassoCut API removes the background from an image with a single POST request. This guide covers a tested curl example, useful options, common errors, and how to repoint a curl call you already send to remove.bg.
Quickstart
Every request needs your key in the X-Api-Key header and exactly one image source. This example uses size=preview, which is covered by your account's 50 free previews per month.
curl -H "X-Api-Key: $LASSOCUT_API_KEY" \
-F "image_file=@photo.jpg" \
-F "size=preview" \
-o no-bg.png \
https://api.lassocut.com/v1.0/removebg
Tested against the production API on 27 September 2026 with this exact request; it returned a valid PNG.
Point an existing curl command at LassoCut
If you already call the remove.bg API with curl, two things change: the host and the key. Flags, form fields and the response format stay the same.
- curl -H "X-Api-Key: $REMOVE_BG_API_KEY" -F "image_file=@photo.jpg" -o no-bg.png https://api.remove.bg/v1.0/removebg + curl -H "X-Api-Key: $LASSOCUT_API_KEY" -F "image_file=@photo.jpg" -o no-bg.png https://api.lassocut.com/v1.0/removebg
For a full parameter-by-parameter comparison, see the migration guide.
Useful options
| Field | Example | Description |
|---|---|---|
size | preview, full, auto | Preview costs 0.25 credit; full and 50MP cost 1 credit; auto picks the largest size your balance allows. |
format | png, jpg, webp | Auto (default) returns PNG when the result has transparency, JPG otherwise. |
type | person, product, car | Selects the model. Auto (default) detects the subject. |
crop, crop_margin | true, 30px | Crops the result to the subject, with an optional margin. |
bg_color | 81d4fa | Fills the background with a hex colour, a colour name, or hex with alpha. |
Full list, including framing, shadows and background images: API reference.
Common errors
Errors return JSON: {"errors": [{"code": "…", "title": "…"}]}. Nothing is charged on an error.
| Status | When | code |
|---|---|---|
| 400 | No image, or two sources given | missing_source, multiple_sources |
| 402 | Not enough credits for this size | title Insufficient credits |
| 403 | Missing or wrong X-Api-Key | titles Missing API Key, API Key invalid |
| 429 | Rate limit reached | title Rate limit exceeded, with Retry-After |
Full list: API reference.
Next steps
Read the full API reference for every parameter and header, or the migration guide if you're moving a script that already calls remove.bg. No key yet? Create a free account, or try LassoCut on your image first, no key required.