withoutBG Open Weights
Open weights · commercially permissiveLicense: Apache-2.0
BiRefNet (legacy)
Open weights · commercially permissiveLicense: MIT

withoutBG Open-Weight Model vs BiRefNet

Quantitative comparison: 33 images scored against ground-truth mattes. Lower is better. Use the view controls on each row to switch between transparency, chroma key, and alpha matte on all outputs.

MetricwithoutBG Open-Weight ModelBiRefNet
MGE (Edge Quality)0.03457 ✓0.03756
MAE (Overall Accuracy)0.01317 ✓0.01456

Disclosure: withoutBG includes BiRefNet

withoutBG Open Weights and Pro Model API are routed pipelines. A classifier sends fine strands, soft detail and transparency to withoutBG's own matting model, and hard opaque objects, flat scenes and vehicles to BiRefNet (MIT license), which is part of the pipeline. On this page, 8 of 33 images went to BiRefNet, so on those images this page partly compares BiRefNet with BiRefNet. The table splits the scores by route: the first group is what withoutBG's own matting model handled.

ImagesMetricwithoutBG Open-Weight ModelBiRefNet
Routed to withoutBG matting (25)MAE0.00988 ✓0.01313
MGE (edges)0.03128 ✓0.03258
Routed to BiRefNet (8)MAE0.023430.01901 ✓
MGE (edges)0.04487 ✓0.05313

Per-image averages, lower is better.

Original photo: autumn bouquet vase
Ground Truth alpha matte: autumn bouquet vase
Alpha matte
withoutBG Open-Weight Model alpha matte: autumn bouquet vase
Alpha matte
BiRefNet alpha matte: autumn bouquet vase
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.07595
MAE
0.02381
BiRefNet
MGE
0.05877✓
MAE
0.01414✓
Original photo: balcony flower planter bokeh
Ground Truth alpha matte: balcony flower planter bokeh
Alpha matte
withoutBG Open-Weight Model alpha matte: balcony flower planter bokeh
Alpha matte
BiRefNet alpha matte: balcony flower planter bokeh
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03402
MAE
0.02906
BiRefNet
MGE
0.03386✓
MAE
0.01461✓
Original photo: balcony plant bokeh
Ground Truth alpha matte: balcony plant bokeh
Alpha matte
withoutBG Open-Weight Model alpha matte: balcony plant bokeh
Alpha matte
BiRefNet alpha matte: balcony plant bokeh
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.04621
MAE
0.01031
BiRefNet
MGE
0.04328✓
MAE
0.00915✓
Original photo: bearded man portrait
Ground Truth alpha matte: bearded man portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: bearded man portrait
Alpha matte
BiRefNet alpha matte: bearded man portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01697
MAE
0.00407✓
BiRefNet
MGE
0.01526✓
MAE
0.00650
Original photo: bike handlebar near beach
Ground Truth alpha matte: bike handlebar near beach
Alpha matte
withoutBG Open-Weight Model alpha matte: bike handlebar near beach
Alpha matte
BiRefNet alpha matte: bike handlebar near beach
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01899✓
MAE
0.00660✓
BiRefNet
MGE
0.02690
MAE
0.01027
Original photo: blowing dandelion seeds
Ground Truth alpha matte: blowing dandelion seeds
Alpha matte
withoutBG Open-Weight Model alpha matte: blowing dandelion seeds
Alpha matte
BiRefNet alpha matte: blowing dandelion seeds
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.04118✓
MAE
0.01690✓
BiRefNet
MGE
0.05031
MAE
0.02854
Original photo: campfire flames night
Ground Truth alpha matte: campfire flames night
Alpha matte
withoutBG Open-Weight Model alpha matte: campfire flames night
Alpha matte
BiRefNet alpha matte: campfire flames night
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01469✓
MAE
0.00695✓
BiRefNet
MGE
0.01813
MAE
0.00906
Original photo: cargo ebike park tracks
Ground Truth alpha matte: cargo ebike park tracks
Alpha matte
withoutBG Open-Weight Model alpha matte: cargo ebike park tracks
Alpha matte
BiRefNet alpha matte: cargo ebike park tracks
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.06638✓
MAE
0.01242✓
BiRefNet
MGE
0.08637
MAE
0.01790
Original photo: compound leaf raindrops
Ground Truth alpha matte: compound leaf raindrops
Alpha matte
withoutBG Open-Weight Model alpha matte: compound leaf raindrops
Alpha matte
BiRefNet alpha matte: compound leaf raindrops
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02498
MAE
0.00460✓
BiRefNet
MGE
0.02200✓
MAE
0.00538
Original photo: confetti sunset portrait
Ground Truth alpha matte: confetti sunset portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: confetti sunset portrait
Alpha matte
BiRefNet alpha matte: confetti sunset portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03139
MAE
0.00959
BiRefNet
MGE
0.02919✓
MAE
0.00875✓
Original photo: dried flowers clay vase
Ground Truth alpha matte: dried flowers clay vase
Alpha matte
withoutBG Open-Weight Model alpha matte: dried flowers clay vase
Alpha matte
BiRefNet alpha matte: dried flowers clay vase
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03577
MAE
0.00660✓
BiRefNet
MGE
0.03499✓
MAE
0.00842
Original photo: elderly man running blur
Ground Truth alpha matte: elderly man running blur
Alpha matte
withoutBG Open-Weight Model alpha matte: elderly man running blur
Alpha matte
BiRefNet alpha matte: elderly man running blur
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01789
MAE
0.00452
BiRefNet
MGE
0.01306✓
MAE
0.00403✓
Original photo: grass seed stem bokeh
Ground Truth alpha matte: grass seed stem bokeh
Alpha matte
withoutBG Open-Weight Model alpha matte: grass seed stem bokeh
Alpha matte
BiRefNet alpha matte: grass seed stem bokeh
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03015
MAE
0.01049
BiRefNet
MGE
0.02752✓
MAE
0.00920✓
Original photo: hanging plant window
Ground Truth alpha matte: hanging plant window
Alpha matte
withoutBG Open-Weight Model alpha matte: hanging plant window
Alpha matte
BiRefNet alpha matte: hanging plant window
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.05026✓
MAE
0.01100✓
BiRefNet
MGE
0.07125
MAE
0.01975
Original photo: messy bun cityscape
Ground Truth alpha matte: messy bun cityscape
Alpha matte
withoutBG Open-Weight Model alpha matte: messy bun cityscape
Alpha matte
BiRefNet alpha matte: messy bun cityscape
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01835
MAE
0.00586✓
BiRefNet
MGE
0.01741✓
MAE
0.00712
Original photo: messy hair bearded portrait
Ground Truth alpha matte: messy hair bearded portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: messy hair bearded portrait
Alpha matte
BiRefNet alpha matte: messy hair bearded portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01551✓
MAE
0.00578✓
BiRefNet
MGE
0.01835
MAE
0.01075
Original photo: orange berries branch
Ground Truth alpha matte: orange berries branch
Alpha matte
withoutBG Open-Weight Model alpha matte: orange berries branch
Alpha matte
BiRefNet alpha matte: orange berries branch
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.05432✓
MAE
0.02385✓
BiRefNet
MGE
0.06849
MAE
0.04935
Original photo: red flower balcony bokeh
Ground Truth alpha matte: red flower balcony bokeh
Alpha matte
withoutBG Open-Weight Model alpha matte: red flower balcony bokeh
Alpha matte
BiRefNet alpha matte: red flower balcony bokeh
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02832
MAE
0.01777
BiRefNet
MGE
0.02034✓
MAE
0.00491✓
Original photo: small fishing boat bw
Ground Truth alpha matte: small fishing boat bw
Alpha matte
withoutBG Open-Weight Model alpha matte: small fishing boat bw
Alpha matte
BiRefNet alpha matte: small fishing boat bw
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02225✓
MAE
0.00549✓
BiRefNet
MGE
0.03319
MAE
0.00839
Original photo: smiling man seaside sunset
Ground Truth alpha matte: smiling man seaside sunset
Alpha matte
withoutBG Open-Weight Model alpha matte: smiling man seaside sunset
Alpha matte
BiRefNet alpha matte: smiling man seaside sunset
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01052
MAE
0.00205✓
BiRefNet
MGE
0.00788✓
MAE
0.00273
Original photo: smiling woman seaside
Ground Truth alpha matte: smiling woman seaside
Alpha matte
withoutBG Open-Weight Model alpha matte: smiling woman seaside
Alpha matte
BiRefNet alpha matte: smiling woman seaside
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02272
MAE
0.00521✓
BiRefNet
MGE
0.02176✓
MAE
0.00757
Original photo: spoked bike wheel
Ground Truth alpha matte: spoked bike wheel
Alpha matte
withoutBG Open-Weight Model alpha matte: spoked bike wheel
Alpha matte
BiRefNet alpha matte: spoked bike wheel
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03536✓
MAE
0.00578✓
BiRefNet
MGE
0.04765
MAE
0.00985
Original photo: sprinter motion blur
Ground Truth alpha matte: sprinter motion blur
Alpha matte
withoutBG Open-Weight Model alpha matte: sprinter motion blur
Alpha matte
BiRefNet alpha matte: sprinter motion blur
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02418
MAE
0.02733
BiRefNet
MGE
0.02044✓
MAE
0.02612✓
Original photo: street dancer studio pose
Ground Truth alpha matte: street dancer studio pose
Alpha matte
withoutBG Open-Weight Model alpha matte: street dancer studio pose
Alpha matte
BiRefNet alpha matte: street dancer studio pose
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02203
MAE
0.00368
BiRefNet
MGE
0.01632✓
MAE
0.00358✓
Original photo: street portrait man
Ground Truth alpha matte: street portrait man
Alpha matte
withoutBG Open-Weight Model alpha matte: street portrait man
Alpha matte
BiRefNet alpha matte: street portrait man
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01403
MAE
0.00312✓
BiRefNet
MGE
0.01295✓
MAE
0.00364
Original photo: sunset field portrait
Ground Truth alpha matte: sunset field portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: sunset field portrait
Alpha matte
BiRefNet alpha matte: sunset field portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02054
MAE
0.00590✓
BiRefNet
MGE
0.01990✓
MAE
0.00769
Original photo: tabby cat portrait
Ground Truth alpha matte: tabby cat portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: tabby cat portrait
Alpha matte
BiRefNet alpha matte: tabby cat portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02730✓
MAE
0.00734✓
BiRefNet
MGE
0.03346
MAE
0.01240
Original photo: terrier dog mugshot
Ground Truth alpha matte: terrier dog mugshot
Alpha matte
withoutBG Open-Weight Model alpha matte: terrier dog mugshot
Alpha matte
BiRefNet alpha matte: terrier dog mugshot
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02940✓
MAE
0.01110✓
BiRefNet
MGE
0.09516
MAE
0.07349
Original photo: two bikes field
Ground Truth alpha matte: two bikes field
Alpha matte
withoutBG Open-Weight Model alpha matte: two bikes field
Alpha matte
BiRefNet alpha matte: two bikes field
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.07739
MAE
0.09324
BiRefNet
MGE
0.05733✓
MAE
0.02197✓
Original photo: two gravel bikes park
Ground Truth alpha matte: two gravel bikes park
Alpha matte
withoutBG Open-Weight Model alpha matte: two gravel bikes park
Alpha matte
BiRefNet alpha matte: two gravel bikes park
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.13603
MAE
0.02861
BiRefNet
MGE
0.12911✓
MAE
0.02761✓
Original photo: windblown curly hair backpack
Ground Truth alpha matte: windblown curly hair backpack
Alpha matte
withoutBG Open-Weight Model alpha matte: windblown curly hair backpack
Alpha matte
BiRefNet alpha matte: windblown curly hair backpack
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02353✓
MAE
0.00573✓
BiRefNet
MGE
0.02467
MAE
0.00789
Original photo: windblown curly portrait
Ground Truth alpha matte: windblown curly portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: windblown curly portrait
Alpha matte
BiRefNet alpha matte: windblown curly portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03757✓
MAE
0.01221✓
BiRefNet
MGE
0.04609
MAE
0.02077
Original photo: woman street portrait glasses
Ground Truth alpha matte: woman street portrait glasses
Alpha matte
withoutBG Open-Weight Model alpha matte: woman street portrait glasses
Alpha matte
BiRefNet alpha matte: woman street portrait glasses
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01677✓
MAE
0.00759✓
BiRefNet
MGE
0.01815
MAE
0.00888

Methodology

  • Alpha mattes are grayscale masks encoding per-pixel foreground probability. They capture fine edge detail (hair, fur, semi-transparent regions) that binary masks discard.
  • Metrics are computed by comparing predicted mattes against a ground-truth reference: MGE measures edge sharpness and MAE measures pixel-level accuracy. Both are lower-is-better.
  • Scored images come from Bench v0, where every image has a ground-truth matte. The benchmark page has the full methodology and per-image scores for every model (CSV / JSON).

BiRefNet run (published results)

Inference settings

  • Input size: 1024 px on the long side (aspect kept, sides rounded to a multiple of 32), then mask resized back to original resolution
  • Normalization: ImageNet mean/std
  • Precision: FP32 (hub weights cast from FP16)