ImportError: DLL load failed while importing snowflake.connector (snowflake-connector-python)
Fixes snowflake-connector-python failing to import its native extension on Windows. Use when import snowflake.connector raises DLL load failed. Not for connection errors.
TL;DR: The connector's native extension cannot find a DLL it needs on Windows. Install the Microsoft Visual C++ Redistributable, then make sure pyarrow and snowflake-connector-python versions are compatible (upgrade both).
ImportError: DLL load failed while importing snowflake.connector: The specified module could not be found.Fix it
- Install the latest Microsoft Visual C++ Redistributable (x64) and reboot. Expected: the missing system DLLs exist.
- Upgrade both packages: pip install -U snowflake-connector-python pyarrow. Expected: compatible pair.
- Verify: python -c "import snowflake.connector; print(snowflake.connector.version)". Expected: a version, no traceback.
- If it persists, check for multiple pyarrow installs or a stale .pyd in site-packages and clean-reinstall.
When this applies
- import snowflake.connector raises DLL load failed on Windows.
When it doesn't
- The import works but connect() fails: network/auth problem, different fix.
- You are on Linux/Mac: DLL errors do not apply; check the actual message.
Compatibility
- snowflake-connector-python 3.x; pyarrow compatible version; Windows 10/11.
Why it happens
The connector ships compiled extensions linked against the VC++ runtime and pyarrow's DLLs. A missing runtime or a pyarrow version whose DLLs moved breaks the load.
Edge cases
- Conda envs sometimes mix pip and conda pyarrow builds; use one installer.
- 32-bit Python on 64-bit Windows causes its own DLL hell; use 64-bit Python.
Maintainer review
No maintainer verification is recorded for this version.
This records the version a maintainer checked. It does not assert that the version is the latest upstream release.