Most Croatian websites lose 30-60% of potential organic traffic due to technical SEO mistakes that can be fixed in a few hours. The most common: slow page load (LCP), missing H1-H6 structure, duplicate content via www and non-www, unoptimized images, and missing schema markup. All checkable for free, all fixable without big projects. Concrete savings for the marketing team: a week of SEO work replaced by a day of technical fixing.
This article shows five real mistakes, how to detect them, and how to fix them.
Mistake 1: Slow page load (poor Core Web Vitals)
The problem: Since 2021, Google uses Core Web Vitals (LCP, INP, CLS) as a ranking factor. Pages that load slower than 2.5 seconds lose positions, especially on mobile.
How to check:
- pagespeed.web.dev - enter your URL
- Look for “Largest Contentful Paint (LCP)” - must be under 2.5s
- “Interaction to Next Paint (INP)” - must be under 200ms
- “Cumulative Layout Shift (CLS)” - must be under 0.1
Most common causes:
- Templates (WordPress, Wix) full of plugins that load even when unused
- Images that aren’t compressed (5MB JPEG when 200KB would do)
- Cookie notice blocking rendering
- Slow hosting (local providers often have slow servers)
How to fix:
- Compress all images (tinypng.com, Squoosh)
- Remove inactive plugins
- Move hosting to a CDN (Cloudflare, Vercel)
- Set up “lazy loading” for all images below the fold
Typical result: PageSpeed score from 30/100 to 80+/100 in 1-2 days of work.
Mistake 2: Missing or wrong H1 structure
The problem: Every page should have exactly one H1 containing the primary keyword. Many sites either have no H1, multiple H1s, or an H1 with generic text (“Welcome”).
How to check:
- Open the page in a browser, click “View page source”
- Search for
<h1>- there should only be one - The H1 content must match what the page wants to rank for
Typical bad example:
<h1>Welcome</h1>
<h1>About us</h1> <!-- second H1, mistake -->Typical good example:
<h1>Plumber Zagreb - emergency interventions 24/7</h1>How to fix: Review every page. Define the primary keyword per page. Rewrite the H1 to include that keyword naturally.
Mistake 3: Duplicate content via www and non-www (or http and https)
The problem: Your site is accessible at both company.com and www.company.com, and both get indexed as different pages. Google doesn’t know which is “the real one,” so it splits authority between them.
How to check:
- Open
company.comin a browser - does it work? - Open
www.company.com- does it also work, on the same page? - Open
http://company.com- does it redirect to https?
If all three versions work without redirection - you have a serious duplicate content problem.
How to fix:
- Set up a 301 redirect from www to non-www (or vice versa, but consistently)
- Set up a 301 redirect from http to https
- Configure canonical tag on every page pointing to the primary version
On Cloudflare: create a Redirect Rule. On nginx: add to config. On a cPanel host: through the Redirects module.
Mistake 4: Images without alt text and too large
The problem: Google can’t “see” images. Alt text is the only way to tell them what’s in the image. Plus, oversized images slow the page down.
How to check:
- Open “Inspect” in the browser
- Check img elements - do they have an
altattribute? - What’s the size (KB) of each image? Above 200KB is a warning, above 500KB is a problem.
Most common example:
<img src="image1.jpg" /> <!-- no alt, useless for SEO -->How it should be:
<img src="plumber-zagreb-price.jpg" alt="Plumber in Zagreb fixing a faucet" />How to fix:
- Audit through screamingfrog.co.uk (free up to 500 URLs)
- Add alt text to every image, descriptively
- Compress all images over 200KB
- Rename images with descriptive names (
image1.jpg→plumber-zagreb.jpg)
Mistake 5: Missing Schema markup
The problem: Schema (structured data) helps Google understand what a page represents. Pages with proper schema more often get “rich snippets” in results - larger display, more clicks.
Most common schemas that work for businesses:
- LocalBusiness - for anything with a physical location (restaurants, salons, plumbers)
- Organization - for any company
- Product - for products in a webshop
- Article - for blog posts
- BreadcrumbList - for navigation paths
How to check:
- search.google.com/test/rich-results - enter the URL
- See what schemas exist and whether they’re valid
How to fix:
Add JSON-LD to the <head> of every page. Example for a plumber:
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "LocalBusiness",
"name": "Plumber Marina",
"image": "https://example.com/logo.jpg",
"telephone": "+385912345678",
"address": {
"@type": "PostalAddress",
"streetAddress": "Ilica 1",
"addressLocality": "Zagreb",
"postalCode": "10000",
"addressCountry": "HR"
},
"areaServed": "Zagreb"
}
</script>Typical result: Pages with schema get 20-30% more clicks in the SERP because they look more visible.
Bonus: 3 quick checks you can do right now
Open your site and:
1. Sitemap.xml check
Type yourdomain.com/sitemap.xml. It should exist and be up-to-date. If it doesn’t exist - big hole.
2. Robots.txt check
Type yourdomain.com/robots.txt. Must exist and must not block important pages. Especially dangerous line: Disallow: / (blocks the entire site from Google).
3. Mobile check Open your site on a phone. Is it readable? Are links easy to click without frustration? Does it load fast? Google is “mobile-first” - the mobile version is the primary version.
What to do next
The flow we recommend:
-
Run a technical audit through free tools: Google Search Console, PageSpeed Insights, screamingfrog (up to 500 URLs free).
-
Make a findings list divided by priority: Critical (blocks indexing), High (impacts rankings), Medium (improvement).
-
Start from Critical and High downward. The mistakes described here are mostly High - big impact on rankings, but fixable without complex development.
-
Measure before and after. Google Search Console shows growth in impressions and clicks after technical fixes - usually visible in 2-6 weeks.
Frequently asked questions
How much does technical SEO actually affect rankings? Estimated at 20-30% of total SEO success. The rest is content and backlinks. But without good technical SEO, even the best content can’t succeed.
Can we fix this ourselves, or do we need an SEO consultant? For WordPress sites - a lot you can do yourself through plugins like Yoast SEO or Rank Math. For custom-built sites - you probably need a developer.
How quickly are results visible? Technical SEO effects are usually visible within 2-6 weeks, but it depends on site size and how often Google crawls. Content changes can take 3-6 months.
Does technical SEO need ongoing maintenance? Yes. Websites degenerate - every new plugin can slow the site, every new piece of content can introduce problems. A monthly check is a good minimum.
Need an SEO audit?
If you suspect your site has technical SEO problems and want a clear plan of what to fix, book a free Discovery call. We do a quick audit and propose priority fixes - no charge for the review.
Reach out at [email protected] or through the form on our homepage.