cONNXr
Pure C ONNX runtime for small embedded devices with zero dependencies.
Pricing
Free tier
Flat rate
Adoption
↘CoolingLicense
Open Source
Data freshness
Aging · Jun 8, 2026Overview
What is cONNXr?
cONNXr is an ONNX runtime written in pure C99, designed to run inference on machine learning models across various frameworks. It's ideal for developers working with constrained hardware due to its minimal footprint and compatibility with older devices.
Key differentiator
“cONNXr stands out as a pure C99 implementation with zero dependencies, making it uniquely suited for environments where resource constraints are critical.”
Capability profile
Capability Radar
Honest assessment
Strengths & Weaknesses
↑ Strengths
↓ Weaknesses
cONNXr is primarily written in C99 and lacks native bindings or extensive documentation for other languages, making it less accessible to developers not familiar with C.
The tool requires manual configuration of the ONNX runtime environment which can be error-prone and time-consuming without detailed setup guides.
While optimized for constrained hardware, cONNXr's performance can suffer when running more complex machine learning models due to its pure C99 implementation and lack of advanced optimization techniques.
Being an open-source project with a niche focus, cONNXr has a relatively small user base which can lead to slower issue resolution and fewer contributions compared to larger projects.
Fit analysis
Who is it for?
✓ Best for
Developers needing to run machine learning inference on devices with very limited resources and no external dependencies
Projects that require a lightweight, standalone ONNX runtime for edge computing tasks
✕ Not a fit for
Applications requiring high-performance GPU acceleration
Environments where the use of external libraries or frameworks is not an issue
Cost structure
Pricing
Free Tier
Available
Open source — free to use
Starts at
$0
Model
Flat rate
Enterprise
None
Performance benchmarks
How Fast Is It?
Ecosystem
Relationships
Next step
Get Started with cONNXr
Step-by-step setup guide with code examples and common gotchas.