Which URL Structure Is Best for SEO in 2025?

Ever wonder why some websites rank higher just because their URLs look cleaner? It’s not magic. It’s simple math: search engines prefer URLs that are clear, short, and tell a story. A messy URL like example.com/index.php?id=123&cat=4&lang=en tells Google nothing useful. But example.com/best-seo-practices-2025? That’s a signal. And in 2025, with Google’s algorithms more advanced than ever, your URL structure still matters-more than most developers think.

What Makes a URL SEO-Friendly?

An SEO-friendly URL isn’t about stuffing keywords. It’s about clarity. Think of it like a signpost on a highway. If someone sees example.com/cheap-shoes, they know what to expect. If they see example.com/product/12345?source=ads, they’re confused. Search engines feel the same way.

Google’s John Mueller has said multiple times: "URLs don’t need to be keyword-rich, but they should be readable by humans." That’s the golden rule. A URL that’s easy for people to understand is also easier for search engines to index and rank.

Here’s what works:

• Use hyphens to separate words (best-seo-tips), not underscores or spaces.
• Keep it short. Under 60 characters is ideal.
• Include the main keyword naturally-don’t force it.
• Avoid parameters like ?id=, &session=, or utm_source= in permanent URLs.
• Use lowercase letters only. Example.com/Best-SEO can cause duplicate content issues.

Static vs Dynamic URLs: Which Wins?

Dynamic URLs are generated by servers on the fly-often from databases. They look like this: example.com/products.php?category=shoes&color=red&size=10. They’re fine for internal use, but terrible for SEO.

Static URLs are hardcoded or rewritten to look clean: example.com/shoes/red/size-10. These are preferred because:

• They’re easier for crawlers to understand and index.
• They’re more likely to be clicked in search results.
• They’re easier to share on social media or in emails.

Most modern CMS platforms like WordPress, Drupal, and even custom Laravel or Django apps support clean URL rewriting. If you’re building a site from scratch, don’t even think about letting dynamic URLs go live. Use URL routing to turn /product?id=123 into /product/123-blue-shoes. It’s not hard-it’s standard practice.

How Deep Should Your URL Hierarchy Be?

Some developers think deeper URLs = better organization. Not true. example.com/category/subcategory/product-name is fine. But example.com/category/subcategory/sub-subcategory/product-name? That’s overkill.

Google recommends keeping your URL structure as shallow as possible. Three levels deep is the max you should aim for. Why? Because:

• Each additional level reduces link equity passed to the page.
• Deeper URLs look less trustworthy to users.
• Crawlers may not reach pages buried too deep, especially on smaller sites.

Think of your site like a tree. The homepage is the trunk. Main categories are branches. Product pages are leaves. If the leaves are too far out, they don’t get enough sunlight-or traffic.

Do Subdomains Help SEO Over Subdirectories?

There’s a myth that blog.example.com is better than example.com/blog for SEO. It’s not. Google treats both the same. In 2025, there’s no ranking advantage to using subdomains for content.

Subdomains are useful for entirely separate products or services: shop.example.com, app.example.com, or support.example.com. But for blog posts, guides, or product pages? Stick with subdirectories.

Why? Because subdirectories help consolidate your site’s authority. All links pointing to example.com/blog/ boost the main domain. Subdomains act like separate sites in Google’s eyes. That means you’re splitting your SEO power.

Case in point: HubSpot moved all their blog content from blog.hubspot.com to hubspot.com/blog in 2022. Their organic traffic grew 37% in 18 months.

What About HTTPS and www?

HTTPS isn’t optional anymore-it’s mandatory. Google has marked HTTP sites as "not secure" since 2018. If your site isn’t on HTTPS, you’re already behind.

As for www vs non-www: it doesn’t matter for SEO. But you must pick one and stick with it. Use a 301 redirect to force consistency. If your site loads both www.example.com and example.com, you’re creating duplicate content. Google will pick one, but you risk losing link equity in the process.

Set your preferred domain in Google Search Console. Then configure your server (Apache, Nginx, etc.) to redirect the other version. It takes five minutes. Not doing it is a silent SEO killer.

Common URL Mistakes Developers Make

Even experienced devs mess this up. Here are the top mistakes I see in real projects:

• Using session IDs or tracking codes in URLs - ?utm_source=facebook should only be on temporary links, never stored in your sitemap or indexed.
• Changing URLs without redirects - Renaming a page? Always set up a 301 redirect from the old URL to the new one. Otherwise, you lose all rankings.
• Using uppercase letters - /Product/ and /product/ are treated as two different pages by some servers.
• Too many numbers or IDs - /post-123456 tells no one anything. Use a slug: /how-to-optimize-urls.
• Not using canonical tags - If you have multiple URLs serving the same content (like with filters), use <link rel="canonical"> to tell Google which one to rank.

How to Audit Your URLs

Here’s a quick checklist to audit your site’s URLs:

1. Run a crawl with Screaming Frog or Sitebulb.
2. Filter for URLs with query parameters (?).
3. Check for uppercase letters or underscores.
4. Look for URLs longer than 80 characters.
5. Find duplicate content across similar URLs.
6. Verify all URLs redirect properly to HTTPS and your preferred domain (www or non-www).

Fix what you can. For big sites, prioritize pages with high traffic or backlinks. A 301 redirect from an old URL to a clean one can recover lost rankings.

Real-World Example: Before and After

Take a real e-commerce product page:

Before: example.com/product.php?cat=shoes&id=8973&color=blue&size=9

After: example.com/shoes/blue/size-9

Now imagine someone sees that URL in a search result. Which one looks trustworthy? Which one will they click? The clean one. And Google notices that click-through rate. Higher CTR = better ranking potential.

Plus, the clean URL is easier to remember. People share it. Bloggers link to it. It becomes a backlink magnet.

Final Rule: Write URLs for Humans First

SEO isn’t about tricking algorithms. It’s about making things easier for people-and search engines follow along.

Ask yourself: If I saw this URL in a tweet, would I click it? If the answer is no, rewrite it.

Good URLs are:

• Short
• Clear
• Readable
• Consistent
• Static

That’s it. No magic. No secret formulas. Just clean, human-centered design.