Slug Checker
Slug Checker inspects a URL slug and tells you whether it follows the conventions search engines and web servers expect: lowercase only, words separated by single hyphens, no spaces, accents or special characters, and no leading or trailing dashes.
Paste a slug or a full title and each rule is checked instantly. When something is off, the tool also proposes a corrected, ready-to-use slug you can copy straight into your CMS or router.
- ✗Not empty
- ✓Only lowercase letters, numbers and hyphens
- ✓No spaces or whitespace
- ✓No uppercase letters
- ✓No accented or non-ASCII characters
- ✓No leading or trailing hyphen
- ✓No consecutive hyphens
- ✓Reasonable length (≤ 75 characters)
How to use Slug Checker
- 1
Paste your slug or title
Enter the URL slug you want to verify, or paste a raw title to see how it would need to be cleaned.
- 2
Read the checklist
Each rule shows a green tick or a red cross so you can see exactly which conventions the slug breaks.
- 3
Copy the suggested fix
If the slug needs work, copy the suggested clean slug and use it in place of the original.
What makes a slug valid and SEO-friendly
A slug is the human-readable part of a URL that identifies a page, for example "slug-checker" in /slug-checker. A good slug is lowercase, uses hyphens (not underscores or spaces) to separate words, contains only unaccented ASCII letters and numbers, and is short and descriptive.
These rules matter because URLs are case-sensitive on many servers, because search engines treat hyphens as word boundaries but underscores as joiners, and because non-ASCII characters get percent-encoded into unreadable sequences like %E2%80%A6 that hurt click-through. Keeping slugs clean avoids duplicate-URL problems and makes links easier to read and share.
How the checks and suggestion work
Each rule is evaluated independently: presence, character set, case, ASCII-only, hyphen placement, consecutive hyphens and length. A slug is reported valid only when every rule passes.
The suggested slug is built by normalizing the input — stripping accents (so "Café" becomes "cafe"), converting the Vietnamese đ/Đ to d, lowercasing, replacing any run of non-alphanumeric characters with a single hyphen, and trimming hyphens from the ends. The result is safe across web servers, content management systems and static site generators.
Frequently asked questions
- Should I use hyphens or underscores in a slug?
- Use hyphens. Google has long treated hyphens as word separators and underscores as word joiners, so "learn-javascript" is read as two words while "learn_javascript" is read as one. Hyphens are the safer SEO choice.
- Are uppercase letters allowed in a URL slug?
- Technically yes, but it is a bad idea. Many servers treat /Page and /page as different URLs, which can create duplicate content and broken links. Always keep slugs lowercase.
- How long should a slug be?
- Shorter is generally better. Aim for a concise slug that contains your main keyword and drop filler words. This checker flags slugs over 75 characters, but most good slugs are far shorter.
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