What makes a good slug
Lowercase words separated by hyphens, no stop symbols, and short enough to read in a link preview. Search engines treat hyphens as word separators (underscores are not), which is why kebab-case is the universal URL convention.
How this tool converts
Accented characters are transliterated to their ASCII equivalents (é → e), symbols and punctuation are dropped, whitespace collapses to single hyphens, and the result is trimmed of leading and trailing hyphens.