ONNX Simplifier Prebuilt

0.4.39.post2 verified Fri May 01 auth: no python

Prebuilt wheels of onnxsim (ONNX Simplifier) distributed as a standalone pip package for platforms that lack a compatible compiler. Current version is 0.4.39.post2, with irregular releases tied to upstream onnxsim updates.

pip install onnxsim-prebuilt

Common errors

error ModuleNotFoundError: No module named 'onnxsim' ↓

cause Forgot to install the package, or installed 'onnxsim-prebuilt' but attempted to import something else.

fix

Run 'pip install onnxsim-prebuilt' to get the prebuilt wheels.

error AttributeError: module 'onnxsim' has no attribute 'simplify' ↓

cause Very old version of onnxsim or onnxsim-prebuilt that does not have the simplify function.

fix

Upgrade to the latest version: 'pip install --upgrade onnxsim-prebuilt'.

Warnings

gotcha Do NOT import from 'onnxsim_prebuilt'. The import module is 'onnxsim', matching the upstream package. The 'onnxsim-prebuilt' name only applies to the pip package. ↓

fix Use 'from onnxsim import simplify' instead of 'from onnxsim_prebuilt import simplify'.

gotcha The 'simplify' function may produce a model that does not preserve output exactness for all ops. Always check the returned boolean flag. ↓

fix After calling simplify, verify that the returned 'check' is True before using the simplified model.

deprecated The function 'check_out' (if used) is deprecated in favor of the built-in check in simplify. ↓

fix Use the return value of simplify instead of calling check_out separately.

Imports

simplify
wrong
```
from onnxsim_prebuilt import simplify
```
correct
```
from onnxsim import simplify
```
The package name on pypi is onnxsim-prebuilt, but the import module is still onnxsim.

Quickstart

Basic usage: load a model, simplify, save.

import onnx
from onnxsim import simplify

# Load your ONNX model
model = onnx.load('model.onnx')
# Simplify the model
model_simp, check = simplify(model)
if check:
    onnx.save(model_simp, 'model_simplified.onnx')
    print('Simplified model saved.')
else:
    print('Simplification failed to preserve outputs.')