whatmodel.sh / image / NextStep-1-Large-Edit

NextStep-1-Large-Edit is an open-weights image model from StepFun, released August 2025. Licence: apache-2.0.

Catalogue identity notes

StepFun NextStep-1 autoregressive image model, editing checkpoint (stepfun-ai/NextStep-1-Large-Edit, pinned bac0d9f, Apache-2.0). Edit-Compass ('Nextstep-V1 Han et al. (2025a)'), UnicBench ('NextStep-1 [34]') and WEAVE ('NextStep-1-Large [66] 15B') evaluate NextStep-1 on image-editing benchmarks; NextStep-1-Large-Edit is the only public NextStep-1 checkpoint fine-tuned for instruction editing (NextStep-1-Large and NextStep-1.1 are text-to-image), so the rows are mapped to it; flagged for the owner in held_for_owner. Comparison-only.

Model information sources

Release date ↗ · Weights licence ↗

37.2±2.9comparison only: no current run option verifiedfrom 3 benchmark results across 3 sources

Score within the LMArena text-to-image comparison set only.

$ how it compares

The image models ranked either side of NextStep-1-Large-Edit, out of 197 with a score, then more from StepFun.

#modelscorewhereRAMreleased
152Stable Cascade Stability AI38±4local~13GB2024-02
153Janus-Pro-7B DeepSeek38±2api $0.0020/image +local~18GB2025-01
154NextStep-1-Large-Edit StepFun37±3comparison only2025-08
155Step1X-Edit v1.0 StepFun37±4comparison only2025-04
156SDXL-Lightning (4-step UNet) ByteDance37±3local~4.9GB2024-02
more from StepFun
89Step1X-Edit v1.2 StepFun53±2local~51GB2025-11
103Step1X-Edit v1.2 Preview StepFun50±5comparison only2025-09
108Step1X-Edit v1.1 StepFun48±3local~51GB2025-07

see all image models · find the ones that fit your machine

$ what it's good at

image to image / editing▁▁▃▃▂▃█▃▃▃▁▁ #76 of 81 * · 79% of its score · 2 tests

Trails OmniGen (v1) here, though they rank lower overall.

testresultvs the others in its rundifficultycountswhy
Edit-Compass (EN, overall)29.0% ✎▃▃▃·▃▆▂█·▃·▃ beats 4/20hard · avg 45%▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 50%typical
UnicBench (EN, overall)64.1% ✎▂····▂▄▂▄·█▂ beats 3/11easy · avg 73%▇▇▇▇▇▇▇▇▇▇▇ 29%at its level
other tests1 not in a task · 17% of its score
testresultvs the others in its rundifficultycountswhy
WEAVEBench in-context multi-turn editing (Avg)53.4% ✎█▄▄·▄▄▄▄█·▄█ beats 5/12medium · avg 65%▇▇▇▇▇▇▇ 17%at its level

$ where to run it

No verified API or download recorded yet · add one

Weights and documentation: huggingface.co/stepfun-ai ↗

$ how the score was worked out · Edit-Compass & EditReward-Com… 50%, UnicEdit-10M: A Dataset and B… 29%, WEAVE: Unleashing and Benchma… 17%

Each result implies a score on its own, after adjusting for how hard its test is and who ran it. The score is their weighted average, with a small pull toward the middle for thinly tested models. Each test's weight is its counts column above; here it's added up by who ran the tests. How it works

$ improve this page

Use a short GitHub form or edit the data through a pull request. Every number needs a source; here's which ones we can use.

data updated · sources and licences · json