What is cffi?
Interact with almost any C code from Python using C-like declarations that can be copy-pasted from header files or documentation.
cffi pricing
Plans, per-tier features and add-ons, dated and linked to live pricing. Pricing changes often; always verify at source before you rely on it.
Free and open source
Open Source
Free- Interact with C code from Python
- ABI mode
- API mode
- Embedding support
- Windows calling conventions
- Thread safety support
Platform & deployment
Independently observed- CLI
cffi FAQ
Common questions about cffi, answered from independent, dated evidence.
What is cffi?
cffi is a Python library enabling developers to call C code from Python programs. It uses C-style function and type declarations that can be directly extracted from C headers or reference documentation, simplifying the process of building Python-C interfaces.
Source: https://cffi.readthedocs.io/
How much does cffi cost?
cffi is completely free and released under an open source license. There are no paid editions, subscription tiers, or licensing fees.
Source: https://cffi.readthedocs.io/
What calling modes does cffi provide?
cffi offers both ABI (Application Binary Interface) mode and API mode. ABI mode allows runtime calls to pre-compiled libraries, while API mode generates C code that integrates with your C extensions.
Source: https://cffi.readthedocs.io/
Can cffi be used in multithreaded applications?
Yes, cffi includes built-in thread safety support. This feature makes it suitable for use in Python applications that rely on multiple threads.
Source: https://cffi.readthedocs.io/
Does cffi support embedding Python in C programs?
Yes, cffi includes embedding support. This feature allows Python code using cffi to be integrated into and called from C applications.
Source: https://cffi.readthedocs.io/
Is cffi compatible with Windows?
cffi supports Windows-specific calling conventions, making it compatible with Windows systems. You can use cffi to call Windows C libraries from Python.
Source: https://cffi.readthedocs.io/
Who is cffi intended for?
cffi is designed for Python developers who need to integrate with C libraries or write Python extensions without manually coding C code. It is useful whenever C-Python interoperability is required.
Source: https://cffi.readthedocs.io/
cffi alternatives
Other developer tools we track, ranked by the same independent score.
The Vioscale score: one lens on the evidence
Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for cffi, not the verdict.
| Signal | Score | Weight | Contribution | Evidence |
|---|---|---|---|---|
| Release Cadence | 59 | 0.12 | 7.1 | ✓ |
| Github Activity | 36 | 0.18 | 6.5 | ✓ |
| Github Stars | 46 | 0.05 | 2.3 | ✓ |
| Security Posture | 0 | 0.14 | 0.0 | - |
| Package Downloads | 0 | 0.28 | 0.0 | - |
| Stackoverflow Activity | 0 | 0.14 | 0.0 | - |
Computed . Re-weight it by intent, or see the full method.
All data & sourcesshow ↓
Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.
Activity
| Attribute | Value | Evidence |
|---|---|---|
| Commits last 30d | 13 | mediumsource · 2026-07-31 · 65% |
Adoption
| Attribute | Value | Evidence |
|---|---|---|
| Github stars | 274 | highsource · 2026-07-31 · 90% |
Content
| Attribute | Value | Evidence |
|---|---|---|
| Faq | [{"answer":"cffi is a Python library enabling developers to call C code from Python programs. It uses C-style function and type declarations that can be directly extracted from C headers or reference documentation, simplifying the process of building Python-C interfaces.","source":"https://cffi.readthedocs.io/","question":"What is cffi?","confidence":0.95},{"answer":"cffi is completely free and released under an open source license. There are no paid editions, subscription tiers, or licensing fees.","source":"https://cffi.readthedocs.io/","question":"How much does cffi cost?","confidence":1},{"answer":"cffi offers both ABI (Application Binary Interface) mode and API mode. ABI mode allows runtime calls to pre-compiled libraries, while API mode generates C code that integrates with your C extensions.","source":"https://cffi.readthedocs.io/","question":"What calling modes does cffi provide?","confidence":0.8},{"answer":"Yes, cffi includes built-in thread safety support. This feature makes it suitable for use in Python applications that rely on multiple threads.","source":"https://cffi.readthedocs.io/","question":"Can cffi be used in multithreaded applications?","confidence":0.9},{"answer":"Yes, cffi includes embedding support. This feature allows Python code using cffi to be integrated into and called from C applications.","source":"https://cffi.readthedocs.io/","question":"Does cffi support embedding Python in C programs?","confidence":0.9},{"answer":"cffi supports Windows-specific calling conventions, making it compatible with Windows systems. You can use cffi to call Windows C libraries from Python.","source":"https://cffi.readthedocs.io/","question":"Is cffi compatible with Windows?","confidence":0.9},{"answer":"cffi is designed for Python developers who need to integrate with C libraries or write Python extensions without manually coding C code. It is useful whenever C-Python interoperability is required.","source":"https://cffi.readthedocs.io/","question":"Who is cffi intended for?","confidence":0.8}] | highsource · 2026-07-31 · 89% |
Language
| Attribute | Value | Evidence |
|---|---|---|
| Primary | Python | highsource · 2026-07-31 · 90% |
Pricing
Release
| Attribute | Value | Evidence |
|---|---|---|
| Cadence days | 74 | mediumsource · 2026-07-31 · 70% |