After auditing thousands of sites, the same ten SEO mistakes show up over and over. They're easy to fix, but only if you know they exist. Here's the list, ordered by how much damage they do.
1. Missing or duplicate title tags
Every page needs a unique, 50–60 character
<title>. Titles are the #1 on-page signal. Duplicate titles
tell Google "these pages are interchangeable", and it will pick one to rank.
2. No meta description
Not a direct ranking factor, but a missing meta description lets Google write whatever it wants in your search snippet. A 150–160 character description with your primary keyword improves click-through rate dramatically.
3. Broken internal links
Every 404 on an internal link wastes crawl budget and breaks the topical hierarchy you built. Audit regularly; redirect or fix every broken link.
4. Images without alt text
Alt text helps Google understand images, improves accessibility, and earns rankings in Google Images. Write descriptive alt text, not "image1.jpg".
5. Non-HTTPS site
HTTPS has been a Google ranking signal since 2014. If your site still serves over HTTP, you're leaking trust signals and losing position to every competitor that invested 30 minutes in Let's Encrypt.
6. No mobile viewport meta tag
Without <meta name="viewport" content="width=device-width,
initial-scale=1">, mobile browsers render your page at desktop width.
Google has indexed mobile-first since 2019, fail this and you fail mobile
rankings.
7. Slow page speed
Google ranks by Core Web Vitals (LCP, INP, CLS) measured in the field. A 4-second LCP isn't just bad UX, it's a documented ranking penalty. See our Core Web Vitals guide.
8. Missing structured data (Schema.org)
Schema markup powers rich snippets: review stars, FAQs, breadcrumbs, product
prices. Sites with rich snippets see 20–30% higher CTR at the same position.
Start with Organization and WebSite schemas; add
Article / Product / FAQ as relevant.
9. Thin content
Pages under 300 words rarely rank for competitive terms. Thin content also triggers Google's Helpful Content System. If a page can't cover its topic in useful depth, consolidate it into a longer page.
10. No XML sitemap
Sitemaps help Google discover pages faster, especially on large or newly launched sites. Submit yours via Google Search Console. Keep it under 50,000 URLs and 50 MB; split into multiple sitemaps if needed.
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