HairWisps without halos
Closed-form foreground matting cleans soft edges. No fringing, even on stark color contrasts.
Public beta · free during beta
Background removal API for developers.
Drop an image in. Get a transparent PNG out. ~200 ms per call. BiRefNet on Modal GPUs. MIT licensed, self-hostable, 40× cheaper than remove.bg.
bash
curl -X POST "https://useknockout--api.modal.run/remove" \
-H "Authorization: Bearer $TOKEN" \
-F "file=@cat.jpg" -o out.pngOriginal
Cutout
200ms
Warm latency, 1024×1024
$0.005
Per image (paid tier)
40×
Cheaper than remove.bg
MIT
Code + model weights
SOTA quality. Real photos.
BiRefNet ranks #1 on DIS5K and HRSOD. We benchmark against remove.bg on hard subjects: hair, fur, glass, group photos.
Hair
GlassTransparent objects
Cocktail glasses, perfume bottles, water — handled cleanly. The matte preserves real opacity.
Multi-subjectGroup photos
Multiple people, overlapping subjects, complex backgrounds. BiRefNet handles them in one pass.
StickersSticker style
iMessage / WhatsApp / Telegram-ready cutouts with a configurable outline width.
One API, twenty endpoints.
Cover the full image-cutout, composition, and enhancement workflow without stitching together half a dozen vendors.
Cutout variants
Enhancement
Install in your stack.
Official SDKs for Node, React, CLI, and Python. Or hit the REST API directly.
npm i @useknockout/node
import { Knockout } from "@useknockout/node";
const client = new Knockout({ token: process.env.KNOCKOUT_TOKEN });
const png = await client.remove({ file: "./input.jpg" });Pricing
For reference — the same image on remove.bg is $0.20 at their PAYG rate.
Free
$050 images / month
Best for: Eval, side projects, OSS
- ✓50 images / month
- ✓No card required
- ✓Public beta token
- ✓Community support
Most popular
Pay-as-you-go
$0.005per image
Best for: Side projects, early startups
- ✓Per-image billing
- ✓Credits never expire
- ✓All 20 endpoints
- ✓Email support
Volume
$0.003per image at 100k+/mo
Best for: Production workloads
- ✓Volume discount
- ✓99.9% uptime SLA
- ✓Slack support
- ✓Usage dashboard
Enterprise
Customprivate endpoints
Best for: Compliance, BYO-cloud
- ✓Self-hosted on your VPC
- ✓Custom SLAs & DPA
- ✓Dedicated support
- ✓Private Slack channel
Frequently asked questions
Warm latency is around 200ms for a 1024×1024 image on a Modal L4 GPU. Cold starts add ~3 seconds. Most production calls hit a warm container.