Technical SEO Checklist: 15 Issues That Silently Tank Your Traffic | AuditMySite

The Invisible Traffic Killers

Most websites lose 30-70% of their potential organic traffic to technical SEO issues that are completely invisible without a proper audit. These aren't content problems or backlink gaps — they're structural issues that prevent Google from properly crawling, indexing, and ranking your pages.

We've audited over 500 websites in the past two years. Here are the 15 most common technical issues we find, ranked by impact on traffic.

Critical Priority (Fix Immediately)

1. Blocked Crawling via robots.txt or Meta Tags

You'd be surprised how often this happens. A developer adds noindex during staging and forgets to remove it. Or robots.txt blocks an entire subdirectory. We've seen sites lose 90% of traffic overnight from a single misplaced robots directive.

How to check: Search site:yourdomain.com in Google. If pages you expect are missing, check robots.txt and meta robots tags immediately. Use Google Search Console's URL Inspection tool for definitive answers.

2. Missing or Duplicate Title Tags

Title tags remain the single most impactful on-page SEO element. Yet 23% of websites we audit have pages with duplicate titles, and 8% have pages with no title tag at all.

Best practices:

Every page gets a unique title tag
50-60 characters (Google truncates at ~600px width)
Primary keyword near the beginning
Brand name at the end, separated by a pipe or dash

3. Broken Internal Links (404s)

Internal links that point to non-existent pages waste crawl budget and create dead ends for users. Sites with more than 5% broken internal links show measurable ranking degradation in our analysis.

Fix: Run Screaming Frog or Sitebulb monthly. Set up redirect rules for any URLs that have been removed. A 301 redirect preserves ~95% of link equity.

4. Missing SSL/HTTPS

Still finding this in 2026. HTTPS has been a ranking signal since 2014. Chrome marks HTTP sites as "Not Secure." There is zero reason not to have SSL — Let's Encrypt provides free certificates, and most hosts offer one-click setup.

5. Slow Page Speed (LCP > 4s)

Page speed is both a ranking factor and a user experience destroyer. Amazon found that every 100ms of additional load time cost them 1% in sales. For a small business, the math is even more punishing because you have fewer visitors to begin with.

Common culprits: unoptimized images, too many plugins (WordPress sites average 20-30), no caching configured, cheap shared hosting with 2+ second TTFB.

High Priority (Fix This Week)

6. Missing or Incorrect Canonical Tags

Canonical tags tell Google which version of a page is the "real" one. Without them, Google guesses — and often guesses wrong. Common scenarios:

HTTP and HTTPS versions both accessible (without redirect)
www and non-www versions both live
URL parameters creating duplicate versions (?sort=price, ?page=2)
Paginated content without proper canonicalization

Rule: Every indexable page should have a self-referencing canonical tag. Every duplicate or variant should canonical to the primary version.

7. Missing Schema Markup

Schema markup doesn't directly influence rankings, but it dramatically improves click-through rates by enabling rich results. Sites with proper schema see 20-30% higher CTR on average.

Priority schema types:

LocalBusiness: Essential for any local business (address, hours, phone)
FAQ: Adds expandable Q&A directly in search results
Product: Shows price, availability, and reviews in SERPs
Article: Helps content appear in Top Stories and Discover
HowTo: Step-by-step instructions shown as rich results

8. Poor Mobile Experience

Google uses mobile-first indexing — meaning it crawls and ranks based on the mobile version of your site, not desktop. If your mobile experience is degraded (hidden content, tiny tap targets, horizontal scrolling), your rankings suffer on both mobile AND desktop.

Test with Chrome DevTools device mode and Google's Mobile-Friendly Test tool. Key checks:

Tap targets at least 48x48px with 8px spacing
Font size minimum 16px for body text
No horizontal overflow
All content visible (not hidden behind "read more" expandables that exist only on mobile)

9. Thin or Duplicate Content

Pages with less than 300 words of unique content are often treated as thin by Google. E-commerce sites are especially vulnerable — product pages with only manufacturer descriptions duplicated across thousands of stores.

Solutions: Add unique product descriptions, customer reviews, FAQ sections, and usage guides. For service businesses, create distinct pages for each service area with location-specific content.

10. XML Sitemap Issues

Your sitemap should be a curated list of your best pages — not an auto-generated dump of every URL on your site. Common problems:

Including noindex pages in the sitemap (contradictory signals)
Including redirected URLs
Missing important pages
Sitemap too large (over 50,000 URLs or 50MB — split into multiple sitemaps)
Not submitted in Google Search Console

Medium Priority (Fix This Month)

11. Missing Alt Text on Images

Alt text serves two purposes: accessibility for screen readers and SEO context for image search. Google Image Search drives 22% of all searches, and you're invisible there without alt text.

Write alt text that's descriptive and includes relevant keywords naturally. "red-kitchen-renovation-sacramento.jpg" with alt="Modern red kitchen renovation in Sacramento home" is better than alt="IMG_4392."

12. Orphaned Pages

Pages with zero internal links pointing to them are "orphaned" — Google may never discover them, and they receive no internal link equity. We commonly find orphaned pages on:

Old blog posts that fell off the main blog listing
Landing pages created for campaigns and never linked internally
Service pages missing from navigation menus

Building strong internal linking structures matters for all types of sites, whether you're building a brand or running a restaurant with a digital presence.

13. Redirect Chains

Page A redirects to Page B, which redirects to Page C, which redirects to Page D. Each hop loses crawl equity and adds latency. Google will follow up to 10 redirects before stopping, but best practice is a maximum of one redirect hop.

14. Hreflang Errors (International Sites)

If you serve content in multiple languages or for different regions, incorrect hreflang tags cause Google to show the wrong language version. This is one of the most complex technical SEO elements — even Google admits their documentation could be clearer.

15. Missing Structured Data for Breadcrumbs

Breadcrumb schema helps Google understand your site hierarchy and displays a clean navigation path in search results instead of an ugly URL. Implementation is straightforward and the visual improvement in SERPs is immediate.

Your Audit Action Plan

Week 1: Fix critical issues (#1-5). These are actively harming your rankings.
Week 2-3: Address high priority (#6-10). These are leaving traffic on the table.
Month 1: Clean up medium priority (#11-15). These are optimization opportunities.
Ongoing: Set up monthly automated crawls to catch regressions.

Recommended Audit Tools

Screaming Frog SEO Spider: Free for up to 500 URLs, comprehensive crawl analysis
Google Search Console: Free, shows how Google sees your site
Ahrefs Site Audit: Automated monitoring with issue categorization
Sitebulb: Visual crawl analysis with prioritized recommendations

Technical SEO isn't glamorous, but it's the foundation everything else is built on. Fix these 15 issues and you'll see measurable improvement within 4-8 weeks.