What is a URL slug?
A URL slug is the human-readable part of a URL that identifies a specific page, typically derived from the page title. For example, in the URL https://example.com/blog/how-to-build-a-rest-api, the slug is 'how-to-build-a-rest-api'. Slugs use only lowercase letters, numbers, and hyphens. No spaces, special characters, or uppercase letters. They are SEO-friendly, readable, and meaningful to both users and search engines.
Why are slugs important for SEO?
Slugs are a key on-page SEO signal. Search engines read the URL slug as an indicator of the page's topic, and keywords in the slug contribute to ranking for those terms. A descriptive slug like /best-email-marketing-tools is more SEO-friendly than /p?id=123. Google's John Mueller has confirmed that words in URLs are a minor but real ranking factor. Slugs also improve click-through rates in search results because users can see the topic before clicking.
Should I use hyphens or underscores in slugs?
Use hyphens (-). Google treats hyphens as word separators in URLs, so 'email-marketing-tools' is interpreted as three separate words. Underscores (_) are treated as character connectors, 'email_marketing_tools' is read as a single word. This is confirmed by Google's own documentation. The hyphen convention is also more readable for humans. This tool defaults to hyphens and recommends them for all new URLs.
Should slugs be lowercase?
Yes. Always use lowercase slugs. URLs are case-sensitive on most servers (Linux/Unix). 'My-Page' and 'my-page' are technically different URLs, and if both exist, you risk duplicate content issues. Search engines generally canonicalise to the lowercase version, but inconsistent casing can waste crawl budget. Using all-lowercase slugs from the start avoids these problems entirely.
How long should a URL slug be?
Aim for 3-5 words, typically 40-80 characters. Shorter slugs are more readable and shareable. Long slugs dilute the keyword signal and look unwieldy in search results and social sharing. For a post titled 'The 10 Best Free Email Marketing Tools for Small Businesses in 2024', a good slug would be 'best-free-email-marketing-tools'. Keeping the main keywords and dropping stop words (the, for, in) and the year (which will make the URL feel outdated). This tool provides an optional max-length setting.
What are stop words and should I remove them?
Stop words are common words like 'the', 'a', 'an', 'in', 'of', 'for', 'and', 'to', 'with', 'is', 'are' that carry little SEO value. Removing them produces shorter, cleaner slugs. For example, 'the-best-tools-for-email-marketing' becomes 'best-tools-email-marketing'. However, removing stop words is optional. Include them if they're important for readability or meaning. This tool generates slugs from your exact title; you can manually trim stop words from the output if preferred.
