A slug is the part of a URL after the final slash — /slugs-that-age-well. It sits alongside the headline but answers a different question. The headline asks will you click? The slug asks will you still trust this link in 2035?
Slugs that age badly are the single biggest source of broken-link rot on the internet. The good news: the fixes are small, mechanical, and you can apply them with any slug generator. Here are the seven rules I've lived by for fifteen years.
Seven rules
1. Short is kinder than specific.
Three to six words. Longer slugs hurt readability, break in emails, and look panicked. /slugs beats /seven-rules-for-writing-slugs-that-age-well-in-2026. You can always redirect; you can't un-send an email.
2. Drop the date.
/2024/03/15/my-post is the fastest way to advertise that your content is stale. Keep dates in the metadata, not the URL. The one exception: news sites where the date is the identifying fact ("election-night-2028").
3. Keywords, not filler.
Strip the, a, of, in — they add length without adding meaning. /history-of-lorem-ipsum → /lorem-ipsum-history. Search engines and humans both scan slugs; filler words slow them down.
4. Lowercase, hyphens, ASCII.
Lowercase prevents the duplicate-content trap where /About and /about resolve separately. Hyphens beat underscores (search engines treat hyphens as word separators; underscores as glue). ASCII-fold your accents — café becomes cafe — unless your audience speaks a language that requires them.
5. Don't mirror the headline.
The headline can change. The slug cannot — or rather, it can, but every change costs you a redirect and some search equity. Write the slug from the topic, not the title. When you rewrite the headline six months from now, the URL will still fit.
6. No stop-words at the start.
Starting a slug with the- or a- is fine, but it makes lists sort poorly and search snippets ugly. Most CMSes let you choose. Always choose no.
7. Plan for the redirect.
Even perfect slugs sometimes need to change — restructures, mergers, rebrands. Set up redirect rules from day one, even if you never use them. When you need them, you'll need them yesterday.
"A URL is a promise. Don't make promises you can't keep." — Tim Berners-Lee, paraphrased
The one exception
All seven rules bend if your site uses slugs as primary keys in a database. Some systems treat the slug as an ID and require uniqueness forever. In that case, add a short numeric suffix (/lorem-ipsum-history-2) when you need to republish, and leave the original intact. The web remembers; your readers don't, but their bookmarks do.
My rule of thumb: if you can't say the slug out loud to a friend on the phone without spelling things out, it's too long.