# npm find-dupes > Identify duplicate dependencies in `node_modules`. > More information: . - List all duplicate packages within `node_modules`: `npm find-dupes` - Include `devDependencies` in duplicate detection: `npm find-dupes --include=dev` - List all duplicate instances of a specific package in `node-modules`: `npm find-dupes {{package_name}}` - Exclude optional dependencies from duplicate detection: `npm find-dupes --omit=optional` - Set the logging level for output: `npm find-dupes --loglevel={{silent|error|warn|info|verbose}}` - Output duplicate information in JSON format: `npm find-dupes --json` - Limit duplicate search to specific scopes: `npm find-dupes --scope={{@scope1,@scope2}}` - Exclude specific scopes from duplicate detection: `npm find-dupes --omit-scope={{@scope1,@scope2}}`