BG-API — Background Removal API

BG-API is a developer REST API that removes image backgrounds using advanced AI — send an image, get back a transparent PNG or WebP, commercial-use safe.

Base URL: https://bg-api.sikasio.com

The API is synchronous: POST /v1/remove processes your image and returns the cutout in the same response — either as raw image bytes (default) or, with response=json, as a hosted URL that stays live for 24 hours.

Quick facts

Base URL

https://bg-api.sikasio.com

Endpoint

POST /v1/remove

Auth

X-API-Key header — instant free key at /signup

Input

JPG, PNG, WebP

Output

Transparent PNG or WebP (or flattened onto a solid bg_color)

Pricing

Free $0 (50 img/mo) · Starter $5/mo (500) · Pro $19/mo (3,500)

Provider

Sikasio · support@sikasio.com

Getting your API key

New here? You can be making your first request in under a minute:

1. Create a free account at /signup — just an email and a password, and accept the terms. No card required.
2. Verify your email by entering the 6-digit code we send you.
3. Copy your API key — it's shown once, right after verification, so save it somewhere safe. You can always see its prefix or regenerate a fresh key from your account dashboard.
4. Already have an account? Sign in. Forgot your password? Reset it here.
5. Make your first call: put the key in the X-API-Key header and POST /v1/remove — see the quick start below.

Authentication

Every /v1 request must include your API key in the X-API-Key header:

X-API-Key: bg_live_YOUR_KEY

An Authorization: Bearer bg_live_YOUR_KEY header works as an alternative to X-API-Key if that's a better fit for your HTTP client.

Missing, wrong, or disabled keys return 401 with code invalid_key. Each successful removal costs one credit from your monthly quota — failed requests are never charged.

Plans & quotas

Quotas reset on the 1st of each month (UTC). Every successful response includes an X-Credits-Remaining header; check GET /v1/account any time.

Price per image vs remove.bg

That works out to roughly 10–25× cheaper per image: BG-API runs its own AI, so there is no per-image licensing cost passed on — and your images are never sent to third-party AI providers.

Quick start

Multipart upload (returns the PNG directly)

curl -X POST "https://bg-api.sikasio.com/v1/remove" \
  -H "X-API-Key: bg_live_YOUR_KEY" \
  -F "file=@photo.jpg" \
  -o cutout.png

Base64 JSON body with options

curl -X POST "https://bg-api.sikasio.com/v1/remove?format=webp&bg_color=ffffff&size=1024" \
  -H "X-API-Key: bg_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d "{\"image_base64\": \"$(base64 -w0 photo.jpg)\"}" \
  -o cutout.webp

Hosted URL instead of bytes (response=json)

curl -X POST "https://bg-api.sikasio.com/v1/remove?response=json" \
  -H "X-API-Key: bg_live_YOUR_KEY" \
  -F "file=@photo.jpg"

{
  "url": "https://bg-api.sikasio.com/files/3f9c…a1.png",
  "width": 1200,
  "height": 800,
  "format": "png",
  "credits_remaining": 3499,
  "expires_in_hours": 24
}

Remove a background

Provide the image one of two ways:

Options (see Options) go in the query string or the JSON body — query wins. Default response is the processed image bytes (image/png or image/webp) plus X-Credits-Remaining and X-RateLimit-Limit headers. With response=json the image is stored and a hosted URL is returned instead (expires after 24 hours).

Check your account

{
  "name": "my-app",
  "plan": "pro",
  "monthly_quota": 3500,
  "used_this_month": 132,
  "remaining": 3368,
  "resets_at": "2026-08-01T00:00:00.000Z",
  "rate_limit_per_minute": 25,
  "max_output_px": 4096,
  "max_upload_mb": 8
}

Fetch a hosted result

Serves images created with response=json. Hosted files are deleted after 24 hours — download anything you need to keep. Hosted storage also has a total capacity cap; if it's full, the oldest files are evicted first, so a URL may expire earlier than 24 hours during heavy usage.

Options

All optional. Pass as query parameters (?format=webp&size=1024) or JSON body fields.

Whatever size you request, the output's longest side is always clamped to your plan's max dimension (see the X-Max-Output-Px response header).

Limits

If the server is momentarily saturated you get 429 busy with a Retry-After header — retry after a few seconds. Only successful removals consume credits.

Errors

All errors are JSON with a stable machine-readable code:

{ "error": { "code": "…", "message": "…" } }

FAQ

curl -X POST "https://bg-api.sikasio.com/v1/remove" \
  -H "X-API-Key: bg_live_YOUR_KEY" \
  -F "file=@photo.jpg" -o cutout.png

Get an API key

Sign up and get a free key instantly — 50 images a month, no card required. Upgrade to starter or pro from your account whenever you need more.

Get your free API key →

Questions? support@sikasio.com