The Essential Technical SEO Checklist I Developed for Client Success

May 15, 2025

The Essential Technical SEO Checklist I Developed for Client Success

Updated: Jun 10, 2025

Over the years, I’ve refined my approach to technical SEO audits through hands-on experience.

This checklist represents my proven system for identifying and fixing the most impactful technical issues affecting search visibility and user experience, which ultimately translates into higher revenue.

Unlike generic SEO guides, this is the actual checklist I created and use with clients to deliver significant improvements.

Each section focuses on elements that genuinely improve search performance and user experience while avoiding time wasted on less consequential optimizations.

Crawlability: Helping Search Engines Discover Your Content

Robots.txt Management

Verify that your robots.txt file is accessible with a 200 status code. This file gives search engine crawlers instructions about which pages they can access and which they should avoid.

Make sure it contains a link to your sitemap to help search engines discover all important pages efficiently.

Check that robots.txt doesn’t block important content on your website, especially pages that should be accessible and resources like JavaScript and CSS, which are critical for rendering content correctly.

Pay special attention to staging or development (sub)domains, which should have crawling forbidden to prevent duplicate content issues.

XML Sitemap Implementation

Ensure your website has an XML sitemap, which is the optimal format for providing structured and comprehensive information about your site architecture to search engines.

XML sitemaps should include all important URLs while excluding non-indexable or low-value pages. They should contain metadata like last modification date and change frequency to help search engines understand your content better.

It is crucial that the XML sitemap remains up to date and is not cached for extended periods, as outdated sitemaps waste crawl budget on non-existent pages.

For large websites with dynamically rendered sitemaps, make sure the server has sufficient resources to handle these requests.

Also, verify that the sitemap has been submitted to Google Search Console. Ideally, check the number of discovered pages to confirm proper processing.

Resolving Crawling Obstacles

Even with properly configured robots.txt and XML sitemap, various crawling issues can prevent search engines from accessing your content. It is essential to ensure that Googlebot and other crawlers can easily access your website without obstacles.

Common problems include server errors, broken pages, excessive redirects, slow response times, and crawl rate limitations.

Monitor Crawl stats in Google Search Console regularly to identify patterns like decreases in crawling, error spikes, or unusual behavior. These could indicate technical issues such as server configuration problems, content delivery issues, or incorrect JavaScript implementation.

For deeper investigation, analyze the website access logs to spot specific crawling patterns or problems.

Optimizing Crawl Budget

Effective optimization strategies include removing unnecessary pages and parameters from URLs, implementing proper pagination, and using canonical tags for duplicate content to focus on valuable content.

Also focus on fixing unnecessary redirects, eliminating thin content, blocking unimportant sections in robots.txt, and improving site speed.

Ensure your internal linking prioritizes important pages to help crawlers find and index your most valuable content efficiently.

Indexability: Ensuring Your Pages Appear in Search Results

Addressing Indexing Issues

First, check the entire website for noindex tags, which should only appear on specific pages you want to keep out of search indexes, such as thank-you pages, account pages, and administrative sections.

Indexability issues often come from incorrect meta tags, robots.txt blocks, server errors, or wrong canonical tags. Even thin or duplicate content creates significant indexing problems.

Pay special attention to canonical and hreflang tags to prevent duplicate content issues, particularly important for e-commerce and international websites.

Incorrectly implemented canonical tags can cause significant traffic loss by consolidating link equity to the wrong URLs.

While canonical tags should be on every website, hreflang tags are only necessary for international sites targeting different languages or regions.

Utilizing Google Search Console’s Indexing Report

Google Search Console provides a comprehensive report of major issues related to website indexing.

The Page Indexing report shows specific issues like server errors, redirect errors, crawled but not indexed pages, and discovered but not crawled URLs.

It also identifies duplicate content without canonical tags, soft 404s, and more, each with affected URLs.

Pay special attention to pages marked “Crawled but not indexed,” which often indicate quality issues that Google has perceived with your content.

Also prioritize fixing server errors and redirect issues as these directly impact user experience. The importance of specific issues varies significantly depending on each website’s unique situation.

Security: Safeguarding Your Business Online

SSL Certificate Implementation

Valid SSL certificates are mandatory nowadays, especially for websites with forms. They encrypt data transmission between servers and browsers, protecting user information.

Beyond security benefits, SSL certificates build trust with users. Search engines also prefer secure sites, with HTTPS being a confirmed Google ranking signal.

Certificate errors or expiration can cause serious disruption, potentially blocking access to your site and triggering alarming security warnings. This damages user trust and leads to significant traffic and conversion drops.

Maintaining Updated Systems

Keeping your infrastructure (Apache, Nginx, PHP, MySQL, etc.) up to date is critical for website security. Outdated server software often contains known vulnerabilities that hackers actively target with automated tools.

Even more important is maintaining an updated CMS with all extensions. WordPress, Magento, and other platforms regularly release security patches, and outdated themes and plugins are among the most common entry points for attacks.

Websites running on outdated systems are vulnerable to automated attacks, which can result in complete deindexing due to malware injections or redirects.

Hackers may insert hidden spam links, malicious JavaScript, or redirect code, triggering Google security warnings. Recovery from these attacks can take months and significant resources, not to mention damage to brand reputation and customer trust.

Advanced Security

While not mandatory, implementing HSTS and CSP significantly enhances your website security. HSTS (HTTP Strict Transport Security) forces browsers to always use HTTPS connections, preventing man-in-the-middle attacks.

Once enabled, even if someone clicks an HTTP link to your site, the browser automatically converts it to HTTPS.

Similarly, CSPs (Content Security Policies) create an allowlist of trusted sources from which content can be loaded, helping prevent cross-site scripting (XSS) attacks, clickjacking, and code injection by specifying exactly which resources are allowed.

Because of the possibility of man-in-the-middle attacks, you should also use absolute links to resources rather than relative ones to maintain security integrity across all pages.

Mobile Optimization: Catering to the Majority of Users

Most websites struggle with responsive design despite understanding that websites should be mobile-first. With mobile traffic accounting for over 60% of all web traffic and Google’s mobile-first indexing, this is no longer optional.

Responsive design should adapt across various screen sizes without horizontal scrolling, overlapping elements, or tiny text. Navigation should be thumb-friendly with appropriately sized tap targets and sufficient spacing between clickable elements.

Keep in mind that all important text from desktop must appear even on smartphone screens to maintain content parity.

Pay special attention to automatic popups during initial loading, as they can block proper content crawling and create poor mobile experiences. Another key factor is a properly set viewport meta tag for correct scaling across devices.

Performance: Speed That Drives Revenue

Passing Core Web Vitals

Passing Core Web Vitals matters not just for Google’s algorithm but mainly for user experience. Studies show that improving them directly correlates with lower bounce rates, longer sessions, and higher conversion rates, leading to higher revenue.

Even small improvements can deliver significant business benefits.

While Core Web Vitals within Google Search Console provide good insights, enhance your analysis with real-user monitoring tools like DebugBear for more comprehensive data that makes fixing issues easier and more effective.

Implementing File Compression

Compression is one of the easiest yet most powerful performance optimizations you can implement.

Compression minimizes the files transferred between the server and the visitor. Modern algorithms like Gzip or Brotli can reduce file sizes by 70 to 90%, dramatically improving load times.

Compressing HTML, CSS, JavaScript, and XML files is standard practice, while images and videos typically have specialized compression formats.

Properly implemented compression not only improves user experience through faster loading but also reduces bandwidth costs for high-traffic sites.

It is particularly impactful for users on slower connections or mobile devices with limited data plans. Setting up compression usually requires minimal server configuration and offers significant performance benefits.

Utilizing Lazy Loading

Lazy loading allows images or videos to load only when needed. During initial page load, only above-the-fold content should load, with everything below loading later as the user scrolls.

This technique drastically improves initial page load time and reduces bandwidth usage, as resources are only requested when they are about to enter the viewport. For image-heavy pages or long-scrolling content, lazy loading can reduce initial load times by over 50%.

Modern browsers support native lazy loading with the loading="lazy" attribute, eliminating the need for JavaScript solutions in many cases.

However, a progressive enhancement approach might use JavaScript as a fallback for browsers without native support. Include appropriate placeholder dimensions to prevent layout shifts during loading.

Do not apply lazy loading to critical above-the-fold images as it would delay visible content that users see immediately.

Effective Caching Strategies

Various caching types can boost website performance. Browser caching through properly set headers is simplest and most accessible.

Other options include CDNs or tools like Varnish for page snapshots, and Memcache, OPcache, or Redis for server-side processing.

Effective caching reduces server load, decreases load times, and improves user experience by serving stored versions rather than repeatedly generating them. For high-traffic sites, proper caching can be the difference between smooth performance and crashes under load.

Different cache lifetimes should be set for different resource types based on how frequently they change. Cache strategy varies widely between sites. News or e-commerce websites need completely different approaches than SaaS company sites or personal blogs.

Optimizing Site Resources

Every website should optimize resources, especially images and videos, but also JavaScript and CSS files to improve performance.

Images and videos should use lossless compression or slightly lossy compression, potentially reducing file sizes by 30 to 95% without noticeable quality loss.

Next-gen formats like WebP and AVIF offer superior compression compared to JPEG and PNG, often reducing file sizes by an additional 25 to 50% while maintaining quality.

For responsive design, use appropriately sized images with srcset and sizes attributes for different devices. Vector formats are ideal for logos, icons, and simple illustrations as they scale perfectly without quality loss.

Also, optimize JavaScript and CSS by loading only what is needed per page. Good practice is splitting them into multiple files and loading the smallest possible code portion for each page.

Minifying these files is suggested since unlimited mobile data or unmetered server bandwidth is not standard for most users and companies.

Additional Speed Optimizations

Beyond the specific performance tasks already covered, other important factors need checking. TTFB (Time To First Byte) should be as small as possible, ideally below 300ms.

Poor TTFB often indicates server issues, inefficient database queries, or excessive processing for dynamic content.

If possible, check MySQL/MariaDB slow query logs and any database tables that might be causing performance issues.

Other major issues include render-blocking resources and excessive DOM, which significantly slow loading times.

Large JavaScript bundles, especially those blocking rendering, can delay interactivity by seconds. Prioritize critical CSS delivery using inline styles for above-the-fold content.

Remember that optimization improves user experience, which often means higher revenue and better conversions. Studies consistently show that faster sites have lower bounce rates, higher conversion rates, and better engagement metrics.

Also verify if all tracking scripts are necessary, as reducing them can significantly boost performance without sacrificing important analytics.

Internal Linking: Creating a Strong Website Structure

Addressing Broken Links

Broken links create dead ends where visitors often leave the website completely. They harm user experience and cause potential crawl budget issues as crawlers waste valuable time on pages that do not benefit your business.

Broken links erode trust in your website credibility while disrupting link equity flow and signaling poor site maintenance to search engines.

Common causes include deleted pages without redirects, typos in manually entered URLs, changes in URL structure during updates, or linking to external pages that no longer exist.

Regular auditing is essential because links that worked yesterday might break tomorrow as external websites change. Implement proper 301 redirects for any pages you remove or relocate to preserve link equity and maintain user experience.

Finding and Fixing Orphan Pages

The golden rule states that each page should be accessible within three clicks from the homepage to ensure proper crawling and user navigation.

Orphan pages have zero internal links pointing to them. These pages receive no internal link equity, have lower crawl priority, and are often missed during routine crawling, limiting their visibility and ranking potential despite potentially valuable content.

For e-commerce sites, orphaned product pages represent missed sales opportunities. Proper site architecture with a maximum of 2-3 levels of depth and strategic internal linking prevents most orphan page issues.

Implementing Strategic Internal Linking

A good internal link structure is one of the most powerful website improvement techniques. Every link should have meaningful anchor text, avoiding generic phrases like “Read more” which provide no context.

Descriptive anchor text helps search engines understand linked page content while clearly signaling to users where the link leads. Including titles for links provides even more information about destination pages.

Your internal linking strategy should prioritize important business pages, creating topic clusters where related content cross-links to establish topical authority.

This helps search engines understand your content hierarchy and expertise in specific areas. Every page should have at least one internal link in the main content to another page. However, avoid excessive internal linking on each page, as it is also a common mistake that can dilute value.

External links should be properly marked as nofollow or sponsored when appropriate to maintain proper link equity flow.

Redirects: Guiding Users and Search Engines Correctly

Selecting Appropriate Redirect Types

Use the appropriate redirect type for each situation. For permanent changes, use 301 redirects, which pass majority of link equity, ideal for site migrations, permanent URL changes, or consolidating duplicate content.

For temporary situations like maintenance pages or seasonal promotions, use 302 redirects.

Consider status code 410 for permanently deleted content, which explicitly tells search engines that content has been removed, helping de-index pages faster than a 404.

Avoid JavaScript redirects and meta refresh, as they are slow, user-unfriendly, and less effective for passing link equity compared to server-side redirects.

Setting Up HTTP to HTTPS Redirects

Even without HSTS implemented, ensure all HTTP requests redirect to HTTPS. This redirect is essential for security and user trust.

Without it, your site effectively exists as two separate websites (HTTP and HTTPS versions), causing duplicate content issues, split link equity, and search engine confusion about your canonical version.

Implement this as a server-level permanent redirect to efficiently pass maximum link equity to the secure version, particularly important if you have legacy backlinks to HTTP URLs.

For sites with mixed content (both HTTP and HTTPS elements), browsers display security warnings that can alarm users and increase bounce rates. Proper redirection eliminates these warnings by ensuring all content loads securely. However, avoid using HTTP links entirely, as the redirects will slow down performance.

Managing WWW and Non-WWW Versions

To prevent duplicate content issues, ensure only one version of your website exists. Typically, the problem is that both www and non-www versions are accessible simultaneously.

Choose one version and redirect all pages from the other version to it. The non-www version appears cleaner and more modern, while the www version clearly identifies the address as a website and provides technical advantages for cookie handling across subdomains.

Implement a server-level permanent redirect from the non-preferred version to maintain link equity and avoid splitting domain authority.

Update all internal links to consistently use your preferred version. Set your preferred domain in Google Search Console and ensure all marketing materials, social profiles, and external communications use the chosen format.

Eliminating Redirect Chains and Loops

Redirects should point directly to destination pages without intermediate redirects. Redirect chains create multiple problems: they waste crawl budget and slow down page loading (adding 300 to 500ms per redirect).

Common causes include multiple site migrations over time and improper redirect implementation during URL structure changes.

Pay special attention to redirect loops, which prevent users and crawlers from ever reaching content, triggering browser errors and causing complete traffic and indexing loss that can severely impact your site performance.

URL Structure: Creating Clear and Logical Paths

Creating a Logical URL Hierarchy

URLs should follow a logical, clear, and consistent hierarchy with a maximum of 2 to 3 levels. Good examples include /blog/ and /blog/title-of-the-blogpost/ or /services/ and /services/technical-seo-audit/.

A logical structure improves user navigation by making URLs predictable and memorable, helps search engines understand content relationships, establishes clear content hierarchy, and facilitates proper analytics tracking.

Each URL segment should represent a logical category or subcategory, becoming more specific from left to right. This creates intuitive breadcrumb navigation and helps users understand their location within your site.

Avoid deep nesting (more than 3 levels) as it creates unnecessarily long URLs.

Crafting User and Search Engine Friendly URLs

All URLs should be easy to read, not too long, and ideally include targeted keywords from your content. Human-readable URLs provide multiple benefits: they are easier to remember, share, and type. Also, they give users and search engines clear context before clicking.

Avoid special characters except for allowed ones. Special characters often require URL encoding (like %20 for spaces), making URLs longer and harder to read.

Separate words with hyphens rather than underscores, as search engines recognize hyphens as word separators. Also, avoid non-Latin alphabets like Cyrillic, Arabic, or Chinese, as they create encoding, compatibility, and sharing problems. Use transcription or transliteration instead for better compatibility.

Standardizing URL Format with Trailing Slash

Choose one URL format, with or without trailing slashes, and ensure only that version exists across your entire website, with the other version redirecting to it.

URLs with and without trailing slashes are considered different by browsers and search engines. Without standardization, you risk duplicate content issues, split link equity, and inconsistent user experiences.

Traditionally, trailing slashes indicate directories while no trailing slash indicates a file. However, modern web servers often handle both formats regardless of resource type.

Consistency is key, so choose one format, implement redirects for the non-preferred version, and use your chosen format consistently in all internal links, sitemaps, and canonical tags to maintain consistency.

Structured Data: Enhancing Search Visibility

Implementing Rich Snippets and Schema Markup

Rich Snippets and Schema Markup significantly enhance visibility in search results. Implement all possible types for maximum effectiveness, ensuring they are error-free since crawlers cannot recognize faulty markup.

Complete even optional fields to gain advantage when competing with similar websites. Structured data helps search engines understand your content beyond text, enabling enhanced search results like rich snippets and knowledge panels, which typically increase click-through rates significantly.

Different content types need different schema: Articles need Article Schema, products need Product Schema, local businesses need LocalBusiness Schema, etc. Each type has specific required and recommended properties.

While implementation methods vary (JSON-LD, Microdata, RDFa), Google strongly prefers JSON-LD as it does not interfere with HTML rendering and is easier to maintain separately from your content.

Validating Schema Implementation

Implementation alone is not enough, structured data must be error-free to be properly crawled and processed. Validate across all pages and fix every mistake to ensure proper functioning.

Common errors include invalid property values, missing required properties, incorrect nesting, duplicate structured data, inconsistencies between visible content and structured data values, and syntax errors in JSON-LD code.

Even small errors can prevent search engines from using your structured data for rich results. For example, a single misplaced comma or bracket in JSON-LD can invalidate the entire block.

Regular validation is particularly important after website updates, content changes, or CMS and extension upgrades, which might break previously working implementations. Set up monitoring to catch issues early before they impact your visibility.

Content Optimization: Crafting Effective Web Content

Optimizing Metadata

Each page needs a unique, descriptive meta title and description, as these serve as advertisements for your website in search results and apps.

Meta titles should be approximately 50 to 60 characters long with primary keywords positioned toward the beginning.

Descriptions should be approximately 150 to 160 characters long with a compelling call to action, key benefits, and naturally incorporated keywords that entice clicks.

Avoid titles and descriptions that are too short or too long as they will be truncated in search results, potentially cutting off important information.

Do not overlook other meta tags like Open Graph, which controls how your content appears when shared on social platforms and can significantly impact click-through rates from social media.

Establishing Clear Heading Hierarchy

While not a strict rule, good heading hierarchy improves readability and accessibility by establishing a clear content structure. Use only one H1 tag per page, containing your primary keyword and accurately describing the main topic.

This helps search engines understand your page’s primary focus and aids users in quickly grasping your content.

Headings should increase by only one level (H1 → H2 → H3, not skipping to H4), creating a logical progression that users and search engines can easily follow.

Headings should be descriptive rather than decorative, focusing on the content beneath them. Proper heading structure significantly improves screen reader navigation for visually impaired users and makes content scanning easier for all readers.

Optimizing Image Alt Texts

Every image should have alt text that describes the image clearly, not generic placeholders. Think of alt text as the only way someone who cannot see would know what is on the image.

Alt text improves accessibility for visually impaired users, provides context when images fail to load, offers keyword relevance signals to search engines, and helps images appear in image search results.

Effective alt text should be descriptive yet concise (ideally under 100 characters), focused on the image content and context within the page, and include relevant keywords naturally without stuffing.

For decorative images with no informational value, use empty alt attributes. Product images should include specific details like color, model, and brand name to maximize search visibility.

Ensuring JavaScript Independence

A crucial but often overlooked rule is maintaining a functional website even without JavaScript. You do not need to follow this strictly, but ensure at least that all content remains visible when JavaScript is disabled.

Many crawlers do not render JavaScript at all, making content invisible to them and potentially hurting your rankings.

While Google can now render JavaScript, it is more resource-intensive and may cause issues. Other search engines, social media scrapers, and older devices often have limited JavaScript capabilities.

Common JavaScript-dependent elements that should have HTML fallbacks include navigation menus, tabbed content, accordion sections, infinite scrolling, and form validation. Links should use anchor tags rather than JavaScript onClick events.

Building Trust and Authority

To build a competitive, trusted website, follow E-E-A-T principles, Google framework for evaluating content quality, particularly for YMYL topics that could impact users’ wellbeing.

Websites should have clear authorship and accessible contacts with real people behind them. Include author bios near articles, with author pages detailing qualifications and relevant experience.

Other E-E-A-T elements include clear editorial policies, fact-checking processes, authoritative source citations, accessible privacy policies and terms of service, and transparent business information such as address and registration numbers.

Many best practices vary by website type. Ensure all content follows Google Quality Guidelines to build long-term trust with both users and search engines.

Accessibility: Creating an Inclusive User Experience

Maintaining Clean and Valid Code

While W3C code validation used to be standard practice, it is now often overlooked. Following these standards makes the internet more accessible for people with disabilities and ensures better compatibility.

Valid code ensures proper interpretation by browsers, screen readers, and assistive technologies. Common validation errors include unclosed tags, duplicate IDs, improper nesting, deprecated elements, and missing required attributes, all causing unpredictable rendering across different browsers and devices.

Beyond accessibility, valid code typically loads faster, is easier to maintain, and provides more consistent user experiences. It helps search engines better understand content structure and relationships between elements.

Clean, valid HTML particularly benefits mobile users, where browser compatibility issues are more common and processing resources more limited, resulting in better performance overall.

Following WCAG Guidelines

While only certain websites are legally required to follow WCAG guidelines, implementing them makes life easier for all users with disabilities, who are potential customers too.

WCAG (Web Content Accessibility Guidelines) covers four principles: Perceivable (information must be presentable in ways users can perceive), Operable (interface elements must be usable), Understandable (information and operation must be comprehensible), and Robust (content must work with various user agents).

Key implementation areas include sufficient color contrast, keyboard navigation, proper form labels, skip-navigation links, descriptive link text, video captions, and proper ARIA attributes for dynamic content.

At minimum, implement basic optimizations like keyboard navigation, accessible forms, and screen reader support to ensure your site remains usable for all visitors.

Putting It All Together

This comprehensive technical SEO checklist represents what I believe are the most impactful elements that truly deserve attention. While thorough, it focuses on areas that genuinely matter for search visibility and user experience rather than less consequential optimizations that waste time and resources.

Technical SEO requires ongoing attention as search algorithms, web technologies, and websites continue to evolve. I regularly update this checklist based on real-world results and industry changes to ensure it remains effective. By systematically addressing these elements, you create a solid foundation for your content marketing efforts and substantially improve your chances of ranking well in search results.

The best approach is to tackle these issues methodically, prioritizing those with the greatest impact on your specific website and business goals. Start with critical issues like crawlability, indexability, and security before moving on to performance optimizations and content structure improvements.

Remember that technical excellence alone is not enough. It must be combined with valuable content that meets user needs and a strategic approach to link building and promotion. When all these elements work together harmoniously, your website will not only rank better but also provide a superior user experience that converts visitors into loyal customers.

2 thoughts on “The Essential Technical SEO Checklist I Developed for Client Success”

    • I mentioned multiple times rendering within tasks. Do you have something specific about rendering in mind?

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