cONNXr
Pure C ONNX runtime for small embedded devices with zero dependencies.
- Status
- UnmaintainedNo commits in 1994 days.
- Last checked
- Checked · Oct 15, 2026
- License
- Open source
- Pricing
- Free tier · from $0
What it is
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.
cONNXr stands out as a pure C99 implementation with zero dependencies, making it uniquely suited for environments where resource constraints are critical.
When it fits — and when it doesn’t
A good fit 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
Look elsewhere if
Applications requiring high-performance GPU acceleration
Environments where the use of external libraries or frameworks is not an issue
Known weaknesses
Each one links to the public issue, changelog or docs page it came from, where we have one.
- 01
Limited language support
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.
- 02
Complex setup process
The tool requires manual configuration of the ONNX runtime environment which can be error-prone and time-consuming without detailed setup guides.
- 03
Performance may degrade with complex models
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.
- 04
Small community and limited support
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.
What it does well
Zero dependencies
Pure C99 implementation
Compatibility with older devices
ONNX model inference support
Minimal footprint
Pricing
- Free tier
- YesOpen source — free to use
- Paid from
- $0
- Model
- Flat rate
- Enterprise plan
- No
Pricing not independently confirmed — check the vendor’s page.
Performance benchmarks
How Fast Is It?
Set up cONNXr
Setup steps, common gotchas and what to check after 30 days.
Get the badge
A small badge for cONNXr’s README or site: its name, “Tracked on AI Navigator”, and the availability status and check month from this page. It updates as the catalog does.
Markdown
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