The slug is the part of a web address that comes after the domain name — the best-email-marketing-tools in example.com/best-email-marketing-tools/. It is one of the most overlooked pieces of on-page SEO, and one of the few that becomes genuinely risky to change later.
A tidy slug does double duty: it gives search engines a low-noise signal about what the page covers, and it gives real people a URL they can read, trust, and remember at a glance. That matters when a link is shared, pasted into a chat, or read aloud.
What makes a good slug
- Short — 3–5 words is usually enough. It does not need to restate the whole title.
- Lowercase, hyphenated — Google treats hyphens as word separators. Underscores are not reliably read the same way, so
email-marketingbeatsemail_marketing. - Keyword-first — include your primary keyword, once, naturally.
- Readable — a stranger should be able to guess the page topic from the URL alone.
- Permanent — no dates or years that go stale, and no numbers that will change when you update the post.
Bad vs good: 5 examples
| Page title | Bad slug | Good slug |
|---|---|---|
| 10 Best Email Marketing Tools for Small Businesses in 2026 | /10-best-email-marketing-tools-for-small-businesses-in-2026/ | /best-email-marketing-tools/ |
| How to Write a Meta Description That Gets Clicks | /?p=1284 | /how-to-write-a-meta-description/ |
| The Ultimate Guide to On-Page SEO (2026 Update) | /the-ultimate-guide-to-on-page-seo-2026-update/ | /on-page-seo-guide/ |
| Best Budget Laptops Under $500 — Top Picks | /best_budget_laptops_under_$500_top_picks/ | /best-budget-laptops-under-500/ |
| What Is Keyword Density? | /post/2026/03/12/untitled-4/ | /what-is-keyword-density/ |
The pattern is the same every time: strip the filler words (a, the, and, of), drop the date, keep the words a searcher would actually type.
How to write one in 30 seconds
- Take your page title.
- Keep the 3–5 words that carry the topic; delete the rest.
- Lowercase everything, join with hyphens.
- Check it reads clearly on its own — no context needed.
- Set it before the page goes live.
Or generate it instantly: paste your title into the free Slug Generator and it will return a clean, lowercase, hyphenated slug — with an option to strip stop words automatically.
The one rule you must not break
Never change a slug after the page is indexed and ranking. Once a URL has backlinks, shares, and search trust, changing it without a proper 301 redirect quietly erases months of progress — every old link becomes a 404. If you must change a URL, set up a 301 redirect from the old slug to the new one first, then resubmit the URL in Search Console.
That is also why dates do not belong in slugs. A slug like /seo-tips-2022/ looks outdated within a year even if the content is still accurate. Put the year in the title if you need it — keep it out of the permanent URL.
Checklist before you publish
- ☐ 3–5 words, keyword included
- ☐ All lowercase, hyphens only (no underscores, spaces, or special characters)
- ☐ No dates, years, or numbers that will go stale
- ☐ Reads clearly without the title for context
- ☐ Unique — no other page on the site uses the same slug
- ☐ Set before publishing, not after