Unicode filename collision checker
Find filenames and directories that become equivalent after Unicode normalization or case folding.
Accepted files: see this tool’s format requirements. Multiple files supported. No total size limit.
Up to 2,000 files. Uses Unicode 17 default full case folding and browser NFC/NFD normalization. Locale-specific Turkish mappings are not applied. Potential equivalence is not proof of a collision on every operating system. Up to 1,000,000 characters. Review the settings before running.
Your result
How to use Unicode filename collision checker
- Choose the folder you want to inspect.
- Review the options and run the check.
- Read the result and download the report.
Useful next steps
Choose one local folder
Use the folder picker and confirm the files you want to inspect. Nested paths are preserved. Choosing another folder replaces the selection.
Review the result
Find filenames and directories that become equivalent after Unicode normalization or case folding.
Download your report
Save the report or manifest to keep the results. Your source files are unchanged, and the processing stays in your browser.