slugify vs change-case

utility

slugify

change-case

In the JavaScript ecosystem, string case conversion is a common task with two distinct approaches: slugify (@sindresorhus/slugify) is a laser-focused tool for generating URL-safe slugs with kebab-case formatting, accent/special character removal, and performance optimizations, while change-case (by Blake Embrey) offers a comprehensive suite of 13+ case converters including camelCase, snake_case, PascalCase, and more with robust TypeScript support.

This comparison matters because choosing the wrong tool impacts bundle size, runtime performance, and maintainability. Slugify targets developers building content management systems, blogs, e-commerce platforms, or any application requiring SEO-friendly URLs. Change-case serves teams working across API integrations, database schema transformations, or codebases requiring multiple case format standards. Understanding their trade-offs prevents over-engineering simple slug needs or under-tooling complex case conversion requirements.

Head-to-Head

Performance (Slug Generation)→ slugify wins

slugify

Wins slug-specific benchmarks by 20-40% over change-case's kebabCase in Slug Race tests. Optimized regex patterns and minimal operations make it the fastest choice for URL slug generation at scale.

change-case

Slower for pure slugification due to general-purpose architecture. KebabCase function lacks built-in special character removal and accent handling, requiring additional processing steps that impact throughput.

Bundle Size Impact→ slugify wins

slugify

Extremely lightweight at ~1-2kB minified. Zero dependencies and single-purpose design means no dead code. Ideal for performance budgets in client-side applications.

change-case

Full package is 10-15kB but supports tree-shaking well. Importing only kebabCase yields ~2kB. Multiple case converters add up quickly if using 3+ formats, but modular architecture keeps individual imports competitive.

API Versatility→ change-case wins

slugify

Single slugify() function with options for custom separators and replacement maps. Handles URL slug edge cases (trimming, deduplication, lowercase) automatically but limited to kebab-case output.

change-case

Provides 13+ dedicated functions (camelCase, snakeCase, constantCase, dotCase, pathCase, etc.). Each converter accepts consistent Options for locale and delimiters. Can compose converters for complex transformations.

Character Handling→ slugify wins

slugify

Excels at transliterating accents (é→e, ñ→n) and removing special characters by default. Built-in logic for URL-safe output including emoji stripping and Unicode normalization. Handles edge cases developers forget.

change-case

Basic ASCII conversion without transliteration. Special characters and accents require manual preprocessing. Designed for case transformation only, not sanitization, which can cause URL encoding issues.

TypeScript Experience→ change-case wins

slugify

Strong typed definitions with option overloads and inference. Community-maintained types are accurate but occasionally lag minor releases. Generic string return type lacks literal inference.

change-case

Native TypeScript implementation with first-class definitions. Excellent type inference across all 13+ converters. Options interface is well-documented with IntelliSense hints. Better DX for TS-first projects.

Ecosystem Maturity→ change-case wins

slugify

Maintained by Sindre Sorhus (high trust factor). 2k+ stars with active maintenance. Smaller community but frequently referenced in slug generation guides. Narrow focus means fewer breaking changes.

change-case

6k+ stars with broad adoption in React/Vue/Angular projects. Larger issue tracker and PR activity indicates wider use. More Stack Overflow questions and third-party integrations. Established standard for case utilities.

Verdict

Choose slugify when your primary need is generating URL-safe slugs for routes, filenames, or SEO-friendly identifiers. Its specialized design handles edge cases like accent transliteration and special character removal that change-case doesn't address, while delivering superior performance and minimal bundle impact. For applications where slug generation is a core feature (CMSs, blogs, e-commerce), slugify's 20-40% speed advantage and 1-2kB footprint make it the clear winner.

Choose change-case when you need multiple case formats across your application—API response normalization, database field mapping, CSS class generation, or cross-platform string conventions. If you're already using 3+ case formats (camelCase for JS, snake_case for databases, kebab-case for CSS), the 10-15kB investment pays off versus managing multiple single-purpose libraries. The superior TypeScript support and ecosystem maturity also make it better for large teams with diverse case conversion requirements. For slug-only needs, change-case is over-engineering; add slugify specifically for that use case.

When to Use Each

**If you are building a blog platform with dynamic post URLs** → use **slugify** because it automatically handles post titles with accents, emojis, and special characters while generating clean, SEO-friendly slugs at optimal speed.

**If you are normalizing API responses from multiple external services** → use **change-case** because different APIs return snake_case, camelCase, and PascalCase, and you need consistent transformation across all formats with one dependency.

**If you are building a file upload system that generates safe filenames** → use **slugify** because it strips dangerous characters and handles Unicode edge cases that could break filesystems, with minimal overhead per upload.

**If you are developing a code generator that outputs TypeScript, SQL, and CSS** → use **change-case** because you need camelCase for TS variables, snake_case for SQL columns, and kebab-case for CSS classes with consistent, well-typed transformations.

Learn More

slugify →change-case →

Head-to-Head

Performance (Slug Generation)→ slugify wins

slugify

Wins slug-specific benchmarks by 20-40% over change-case's kebabCase in Slug Race tests. Optimized regex patterns and minimal operations make it the fastest choice for URL slug generation at scale.

change-case

Bundle Size Impact→ slugify wins

slugify

Extremely lightweight at ~1-2kB minified. Zero dependencies and single-purpose design means no dead code. Ideal for performance budgets in client-side applications.

change-case

API Versatility→ change-case wins

slugify

Single slugify() function with options for custom separators and replacement maps. Handles URL slug edge cases (trimming, deduplication, lowercase) automatically but limited to kebab-case output.

change-case

Character Handling→ slugify wins

slugify

change-case

TypeScript Experience→ change-case wins

slugify

Strong typed definitions with option overloads and inference. Community-maintained types are accurate but occasionally lag minor releases. Generic string return type lacks literal inference.

change-case

Ecosystem Maturity→ change-case wins

slugify

Maintained by Sindre Sorhus (high trust factor). 2k+ stars with active maintenance. Smaller community but frequently referenced in slug generation guides. Narrow focus means fewer breaking changes.

change-case

Verdict

When to Use Each