Know how your model behaves.Then change it.
Senbonzakura shows how your model behaves, and how to change it.
Windows and Linux · Made for AI labs and enthusiasts · Models stay on your computer
The problem
Why open models are hard to trust.


It still says no.
Refusals. In a Scale AI study, safety tuned models refused 43.8% of system hardening requests: 44 in 100.


A black box with billions of parts.
Architecture. Qwen3-1.7B is 28 layers and 1.7 billion numbers. Nothing shows you what's in there.


Edit blind, break it.
Blind edits. Change the wrong part and the model loops, rambles or forgets how to answer.
What it does
Senbonzakura, on your own computer.


Refusals removed, with proof.
Refusal removal. The refusal removed, the rate measured, and a check on how much every other answer changed. Measured on Qwen3-1.7B: hard refusal 0.1%, drift 0.050, mean of 5 seeds over 200 held-out prompts.


See the whole model.
Workspace. Every layer laid out as blocks you can open, on your own computer.


Know which layers matter.
The map. The map measures where refusal lives, block by block, against controls.
Also
The rest of the toolkit.


Only models that fit.
Fit check. Real Qwen3 file sizes at Q8_0. See what fits your card before you download a byte.


Shrink it to fit.
Quantise. Quantise Qwen3-8B from Q8_0 (8.71 GB) to Q4_K_M (5.03 GB) and see what it cost in quality.
Plans
Compare the plans.
| Feature | Developer | Basic |
|---|---|---|
| Price | Free | |
| Open and download models | Yes | Yes |
| The model map | Yes | Yes |
| The fit check | Yes | Yes |
| Refusal rate and where refusal lives | Yes | Yes |
| Plain explanations | Yes | Yes |
| Edit size | No | Yes |
| A check on how much the answers changed | No | Yes |
The founder price is struck through the list price for Basic.
Prices are the same number in dollars, pounds and euros. Paddle, which sells the plans, works out the tax. Each account has one session at a time.
Before you pay
Four things people ask first.
Is this dodgy?
The rules are in our acceptable use policy, and every edit is measured and shown, not hidden.
Will it break my model?
It shows what else moved, so you see the cost before you use the model.
Do I need to code?
No. It is a desktop app with buttons.
Does my model leave my computer?
No. Models and prompts never leave your computer.