Slugification

Slugification is the process of converting a string, typically a page title or category name, into a URL-friendly slug. A slug is a lowercase, hyphen-separated string that can be embedded in a web address. Slugs improve readability, memorability, and search engine optimization, and they help ensure URLs remain stable when content is updated.

Common rules for slug generation include converting to lowercase, removing or transliterating non-alphanumeric characters, replacing spaces and punctuation with hyphens, collapsing consecutive hyphens, trimming leading or trailing hyphens, and sometimes limiting the overall length. Unicode handling may involve transliterating non-Latin characters to ASCII or preserving them with careful encoding. Normalize the input to a stable form to avoid inconsistent results. Hyphens are widely preferred over underscores or other separators, though exact conventions vary by system.

Slug generation can be implemented in various ways, using slugify utilities or custom functions across programming languages. Some systems preserve certain characters or implement locale-aware rules to handle multilingual content. Ensuring idempotence—reapplying the slugification process yields the same slug—is common, though practical implementations also address collisions by appending numeric suffixes or otherwise guaranteeing uniqueness within a site.

Uses and considerations include routing in web applications, search engine optimization, and content management workflows. Slugs are different from URL encoding, as they aim to be human-readable and meaningful, while encoding protects characters in transit. Proper slugification balances readability, stability, and correctness across languages and platforms.