Security
PyPI Package Name Validator
Enter a PyPI package name to validate it against PEP 508 naming rules and compute its PEP 503 normalized form. Checks character set, boundary characters, and normalization conflicts. All validation runs in your browser.
No data is transmitted — everything runs locallyTool
About this tool
PyPI Package Name Validator
The PyPI Package Name Validator checks package names against PEP 508 rules and returns the PEP 503 normalized form, character violations, and boundary character issues.
• Check a new package name before uploading to PyPI to avoid a rejected upload
• Compute the PEP 503 normalized form to verify your name is distinct from existing packages
• Debug a 'The name is too similar to an existing project' rejection from PyPI
• Verify that your package name is importable as a Python module identifier
Next step
Alerting Threshold Calculator — Compute multi-window SLO burn rate alert thresholds from the Google SRE Workbook method.
Open Alerting Threshold Calculator →
FAQ
What does this tool tell you?
The PyPI Package Name Validator checks package names against PEP 508 rules and returns the PEP 503 normalized form, character violations, and boundary character issues.
What affects the result most?
PyPI name validation follows PEP 508: [A-Za-z0-9] plus hyphens, underscores, periods. PEP 503 normalization: all names lowercased and runs of [-_.] collapsed to single hyphen. my-package == my_package == My.Package under PEP 503 normalization.
How should I use the result?
Treat the tool's output as a first-pass check, not a proof of correctness. A clean pass means no issues in the patterns this tool recognizes; a failure points to a specific problem you can investigate in your source. The underlying spec is the authoritative source for edge cases.
Related tools