Overview
Introduction
Blog post titles, product names, and page headings all need a clean, predictable identifier for use in a URL, no spaces, no accents, no punctuation a browser or file system would choke on. That identifier is a slug.
Writing that transform by hand is fiddlier than it looks. A naive replace(/ /g, '-') leaves accented letters, curly quotes, and stray symbols in the output, and getting it wrong produces a slug that looks fine in a text editor but breaks the moment it's used as a URL path segment or a filename on a case-sensitive filesystem.
What Is Slug Generator?
A slug is a lowercase string containing only letters, digits, and hyphens, typically derived from a longer human-readable title, and commonly used as the final segment of a URL path.
It's the same convention you see in a blog platform's /posts/10-tips-for-better-photography or a documentation site's /docs/getting-started: short, readable at a glance, and safe to type, bookmark, or share without any character needing to be escaped.
How Slug Generator Works
The tool lowercases the input, Unicode-normalizes it (NFKD) to separate accented letters from their accent marks, strips those accent marks, replaces every run of non-alphanumeric characters with a single hyphen, and trims any leading or trailing hyphens.
The NFKD step is what lets 'café' become 'cafe' instead of 'caf' or a mangled byte sequence. Normalization decomposes the é into a plain e plus a separate combining accent character, and a Unicode range regex then removes just the accent marks, leaving the base letters intact.
When To Use Slug Generator
Use it when generating a URL path segment from a blog post title, creating a filename from a document name, or producing a stable CSS class or HTML id from arbitrary text.
It's especially handy anywhere a title might contain accents, curly quotes, or emoji that would otherwise need manual cleanup. Paste the raw title in and get something safe to store as a permalink or route parameter.
Often used alongside Lowercase Text Converter.
Features
Advantages
- Strips accents intelligently instead of dropping accented letters entirely.
- Collapses multiple consecutive spaces or symbols into a single hyphen, avoiding double hyphens.
- Produces output safe to use directly in URLs, filenames, and CSS identifiers.
Limitations
- Doesn't guarantee uniqueness. Different inputs can slugify to the same output.
- Only handles scripts that Unicode NFKD normalization can decompose into base + accent. Some non-Latin scripts won't be transliterated into ASCII.
Slug Generator vs. Lowercase Converter
| Slugify (this tool) | Lowercase only | |
|---|---|---|
| Strips accents | Yes | No |
| Replaces spaces and punctuation with hyphens | Yes | No |
| Lowercases the text | Yes | Yes |
| Safe to use directly in a URL | Yes | No |
Examples
Best Practices & Notes
Best Practices
- Enforce slug uniqueness at the application level (e.g., by appending a counter or ID) rather than relying on the slug alone.
- Slugify consistently at creation time and store the result, rather than re-slugifying the title on every request.
- Keep slugs reasonably short, since very long titles produce unwieldy URLs even after slugifying.
- Handle the 'no alphanumeric characters' error explicitly in your own code path instead of assuming a slug is always produced. Text that's entirely punctuation, emoji, or non-Latin script will hit it.
- Need true transliteration of non-Latin scripts rather than accent-stripping? Use a dedicated transliteration library. NFKD normalization alone won't Romanize Cyrillic or CJK text.
Developer Notes
This relies on String.prototype.normalize('NFKD') to decompose accented characters before stripping combining marks with a Unicode range regex. No transliteration library is used, so non-Latin scripts pass through only as far as NFKD can decompose them, which for most non-Latin scripts is not at all, leaving those characters to be removed by the subsequent /[^a-z0-9]+/g collapse rather than converted to anything. The empty-input check runs on the trimmed input before any transformation, and a second, separate check after the full pipeline catches input that survives that initial check but reduces to nothing once accents, punctuation, and non-alphanumeric characters are all stripped away.
Slug Generator Use Cases
- Generating a URL path segment from a blog post or article title
- Creating a safe filename from a user-provided document name
- Producing a stable HTML id or CSS class name from arbitrary text
- Sanitizing a filename generated from a user-provided product or document title before saving it to a filesystem
Common Mistakes
- Assuming slugify guarantees uniqueness across an entire site without an additional uniqueness check.
- Re-slugifying a title on every page load instead of storing the slug once, causing URLs to change if the title is edited.
- Assuming slugify will transliterate non-Latin scripts into readable ASCII, when unsupported scripts are stripped entirely rather than Romanized.
- Not handling the empty-result error case for input that's entirely punctuation, emoji, or non-Latin text.
Tips
- Two records might produce the same slug? Append a short unique suffix (like an id) rather than relying on the text alone.
- Run the result through the lowercase tool if you're combining it with other manually-typed URL segments to keep casing consistent.
- Slugifying returns an error on text that looks like it has real words? Check whether that text is in a non-Latin script. NFKD only decomposes accented Latin characters, not other alphabets.