SEO-Friendly URLs: What They Are and How to Write One

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Short answer: An SEO-friendly URL is a web address a person can read and guess the page from, like yourbakery.com/sourdough-classes instead of /page?id=4471. To write one, use real words, separate them with hyphens, keep it lowercase and short, include your main keyword once, and skip dates.

Picture two doors on the same street. One has a sign that reads "Sourdough Classes, Saturdays." The other has a laminated card taped to it that reads "Room 4471." Both lead somewhere. Only one tells you what is inside before you open it. Your page URLs work the same way, and the good news is that fixing them is a small, do-it-once job you can finish in an afternoon.

What is a URL, and what is a "slug"?

A URL is the full web address of a page: the whole line in the browser bar. For a bakery selling classes, it might be yourbakery.com/sourdough-classes. The last, page-specific part, the /sourdough-classes bit, is called the "slug." That is the piece you control and the piece this whole guide is about. Your domain (yourbakery.com) stays the same across every page. The slug changes for each one, and it is the part that either describes the page or hides it behind a code.

You have seen both kinds without thinking about it. /gift-boxes tells you exactly where you are. /page?id=4471 tells you nothing. The slug is where an SEO-friendly URL is won or lost.

What makes a URL SEO-friendly?

A URL is SEO-friendly when a human can read it and correctly guess what the page is about. That is the entire test. /sourdough-classes passes because a customer glancing at it knows what they will find. /index.php?topic=42&area=3a5ebc944f41 fails because it is a machine string, readable only to a database.

This is not just a nicety for people. Google's own URL guidance says to use readable words rather than long ID numbers, and it puts the two side by side: it holds up example.com/wiki/Aviation as the good version and example.com/index.php?topic=42&area=3a5ebc944f41daa6f849f730f1 as the one to avoid. Same advice for your customer and for the search engine, which is the pattern you will see again and again below. A clean address helps both at once. If you want the wider picture of how the URL fits alongside everything else on a page, on-page SEO basics covers the full checklist.

Use real words, not ID numbers

Start here because it is the rule everything else builds on. When your website software offers to name a new page, it will often reach for a number or a random string by default. Change it to words. A page about gift boxes should live at /gift-boxes, not /product-1187.

This is Google's first piece of URL advice, not a preference someone invented. Its documentation says plainly: "When possible, use readable words rather than long ID numbers in your URLs." Words in the slug do a quiet second job too. When another site links to your page, or when someone pastes the raw address into a message, the words themselves describe the destination. A number describes nothing.

Separate words with hyphens, not underscores

Once you are using real words, you have to join them somehow, and there is exactly one right way. Use a hyphen. /sourdough-classes, not /sourdough_classes and not /sourdoughclasses.

Google is specific about this. Its guidance recommends hyphens instead of underscores because, in its words, it "helps users and search engines better identify concepts in the URL," and it tells you to avoid running words together like /greendress. The reasoning is simple. To Google, a hyphen reads as a space between two separate words. An underscore reads as glue, so sourdough_classes can be treated as one long unbroken word. Hyphen keys are one press away. There is no reason to use anything else.

Keep every URL lowercase

Type your slugs in lowercase and never mix in a capital. This one surprises people, because it feels like it should not matter. It does.

Google treats URLs as case-sensitive. Its documentation states that it "treats both /APPLE and /apple as distinct URLs with their own content," and it advises you to convert all text to the same case so it can tell that two addresses point to the same page. Read that again with your own site in mind. If a link somewhere points to /Sourdough and your real page is /sourdough, Google can see two pages where you have one. That splits your signals and can create the kind of accidental copies covered in duplicate content and how to avoid it. Lowercase, always, closes the door on the whole problem.

Keep it short and lead with your keyword

Say what the page is, then stop. /sourdough-classes is finished. /our-wonderful-range-of-artisan-sourdough-baking-classes-for-beginners is not better, it is worse. Drop the filler words: "the," "and," "a," "our." They add length and carry no meaning.

There is data behind the instinct to keep it tight. Backlinko analyzed 11.8 million Google search results and found a strong correlation between short URLs and higher rankings. That is a correlation, not a promise that trimming a slug lifts you up the page, and it is worth being honest about the difference. But it points the same direction as common sense: a short, clean address is easier to read, easier to link to, and easier to remember. Lead with the words that matter and cut the rest.

Across the small-business sites we help at Fonzy, the machine-string URL is one of the most common things we find, and it almost always traces back to the same moment: the site was built fast, the software auto-named the pages, and nobody thought to change it. The pages work. Customers still land on them. But the address is /page?id=88 when it could have said /wedding-cakes, and that is a free, five-minute improvement sitting untouched. It is rarely the biggest problem on a site. It is almost always the easiest one to fix.

Include your keyword once, then stop

Put your main keyword in the slug a single time, naturally. A page about wedding cakes should be /wedding-cakes. It should not be /wedding-cakes-wedding-cake-cakes-wedding. Repeating the term does not help and looks like exactly what it is.

Here is the part that keeps this in perspective. Keywords in the URL are only a tiny ranking factor. John Mueller of Google has said it is "a very small ranking factor, so it's not something I'd really try to force," and that it is not worth restructuring your site just to cram keywords in. He has separately called it "overrated" and "a very, very lightweight ranking factor." So include your keyword because it makes the address readable, not because it will move you up the results. If you are still working out what your keyword even is, start with what keywords are and how to find yours first.

One more thing to keep straight: the URL is not the clickable blue headline you see in search results. That headline is the title tag, and it is a separate job with its own rules, covered in how to write page titles. The URL sits just under it. Both matter, in different ways.

Leave the date out of the URL

Do not put a year in the slug of a page you plan to keep. /sourdough-classes-2024 looks fine the day you publish it. Then the year turns over, the page is still current, and now the address itself says "old." Worse, if you update the page, the URL either lies or you are stuck changing it, and changing URLs has real costs (more on that next).

Backlinko flags dates in URLs for exactly this reason: they make the address longer and harder to update later. Keep the slug about the topic, not the calendar. The page about your classes is /sourdough-classes for as long as you offer classes, which is the point.

Set the URL once, then leave it alone

This is the rule that saves you the most pain. Pick a clean slug the day you publish, and then do not touch it. A live URL has quietly earned things: links from other sites, bookmarks, its spot in Google's index, its history. All of that is tied to the exact address. Change the address and you put every bit of it at risk.

If you are naming pages on a fresh site, this is your one chance to get it right for free, before anything is linked or indexed.

If you must change a URL, redirect the old one

Sometimes you have no choice. You are rebranding, restructuring, or cleaning up a genuine mess. When that happens, you must send the old address to the new one with a 301 redirect. A 301 is a permanent redirect: it tells Google the page has moved for good and to carry its ranking history over to the new URL. Google's site-move guide is direct about it: use server-side permanent redirects such as a 301 wherever technically possible, because a permanent redirect passes ranking value to the new URL. Skip this step and you do not move the page, you delete it and start a new one from zero.

Even done correctly, a URL change can cost you for a while, and it is worth hearing that from someone it happened to rather than from us. One site owner, posting as "BeKo 8064" in Google's own Search Central Help Community, described it plainly: after changing their URL structure and setting up 301 redirects, "most of our organic rankings and traffic dropped significantly," and recovery was "slow and only partial." They did the redirects. They followed the rule. It still hurt. That is the honest reason the previous rule exists: set the URL once, then leave it alone.

How much does a good URL really matter?

Less than you might fear, which is the reassuring part. A clean URL helps a little and cannot hurt, but it is not the lever that makes or breaks your rankings. Google itself calls keywords in the URL a very small factor. Your content, your reviews, and whether pages actually answer what people are searching are all doing far more work.

So treat the URL for what it is: a small, do-it-once fix. On a new page, spend the thirty seconds to name it well. On an existing page that already ranks, usually the safest move is to leave the URL exactly as it is. If your site runs on a common platform, the field to edit is right there when you create or edit a page, and platform-specific guides like WordPress SEO basics show you where it lives.

Frequently asked questions

Should I change my old URLs to make them SEO-friendly?

Usually not, if those pages already get traffic. A live URL has earned links and rankings tied to its exact address, and changing it puts those at risk even with a correct redirect. If a page barely gets visits, cleaning it up is lower risk. If it ranks well, leave it alone and apply the clean-URL rules to new pages instead.

Do keywords in the URL help my rankings?

Only a little. John Mueller of Google has called keywords in URLs a "very small" and "overrated" ranking factor, not worth restructuring a site over. Include your main keyword once because it makes the address readable for a human, not because it will lift you up the results.

What is the difference between a URL and a page title?

The URL is the web address in the browser bar, like yourbakery.com/sourdough-classes. The page title is the clickable blue headline that shows in Google's search results, and it is a separate setting with its own rules. Both matter, but they are two different jobs.

Are hyphens or underscores better in a URL?

Hyphens. Google recommends hyphens over underscores because a hyphen reads as a space between separate words, while an underscore can glue two words into one. Use /sourdough-classes, never /sourdough_classes.

Clean URLs are the kind of quiet, do-it-once fix that is easy to skip because nothing breaks when you ignore it. Name each page like the sign on that first door: a few plain words, in lowercase, joined by hyphens, that tell a customer and Google exactly what is inside. Fonzy handles this kind of groundwork automatically, so the boring-but-right details are done for you and you can get back to running the shop.

Sources

Roald

Founder Fonzy. Obsessed with scaling organic traffic. Writing about the intersection of SEO, AI, and product growth.