A technically sound website gives search engines a better chance of discovering, understanding and indexing your pages. That matters even more as search continues to evolve, with AI Overviews appearing for an increasing share of queries.
But technical SEO isn’t about ticking off a list of warnings and calling the job done. A good technical SEO checklist helps you identify the issues that could be limiting your website’s visibility, understand which ones matter most and prioritise the fixes that can have the greatest impact.
In this guide, we’ll walk through the technical SEO checks worth paying attention to, from crawlability and indexing to Core Web Vitals, structured data, mobile performance and security. We’ll also explain how SMP approaches technical SEO when a checklist isn’t enough.
What Is a Technical SEO Checklist and Why Does It Matter?
A technical SEO checklist is a set of checks used to assess the technical elements that affect how search engines access, understand and index a website.
It covers areas that aren’t always visible to visitors, including crawlability, indexability, site architecture, page performance, structured data, mobile behaviour and security.
These foundations matter because even strong content can struggle to perform if search engines can’t access the pages properly or understand which versions should appear in search.
Technical SEO also supports the wider SEO strategy. Content, internal links and authority all have more opportunity to deliver results when the website underneath them is technically sound.
If you want to see how technical SEO fits into a wider search strategy, our SEO services cover the broader optimisation process alongside the technical foundations.
Crawlability Checklist: Can Search Engines Find Your Pages?
Before a page can be indexed, search engines need to be able to discover and crawl it. That’s where a crawlability checklist comes in.
Crawlability is about making sure search engine crawlers can access the pages that matter without wasting resources on URLs that don’t need to be crawled.
On larger websites, this becomes particularly important. Research from Digital Applied has suggested that around 30% of crawl budget on sites with more than 10,000 pages can be wasted on duplicate or low-quality URLs.
A practical crawlability checklist should include:
- Robots.txt — check that important sections aren’t accidentally blocked.
- XML sitemaps — make sure your sitemap contains the important URLs you want search engines to discover and doesn’t include unnecessary or broken URLs.
- Internal links — important pages should be reachable through useful internal links rather than existing as orphans.
- Status codes — identify unexpected 4xx and 5xx responses that could prevent pages from being accessed.
- Redirects — identify unnecessary redirect chains and loops that could make crawling less efficient.
- URL structure — keep important pages accessible through a logical site hierarchy.
Together, these checks help make sure search engines can access and discover the pages that matter.
If your website relies heavily on JavaScript, it’s also worth checking that important content and links can still be accessed and rendered correctly.
Once search engines can access your pages, the next step is checking whether those pages are eligible to appear in search.
Indexing Checklist: Are Your Important Pages Eligible to Appear?
Crawling and indexing aren’t the same thing.
A search engine may successfully crawl a page without including it in its index. That’s why an indexing checklist needs to look beyond whether a URL can be accessed.
Start by checking:
- Noindex directives — make sure important pages haven’t been excluded accidentally.
- Canonical tags — confirm they point to the preferred version of a page.
- Duplicate URLs — identify multiple versions of substantially similar content.
- Thin or low-value pages — review whether every indexable page genuinely contributes value.
- Internal linking — make sure important pages aren’t isolated from the rest of the site.
- Indexation status — compare the pages you expect to be indexed with what search engines actually have available.
A common example is a page carrying a noindex directive that was left behind after development or testing. The page may be live and accessible to users, but it won’t be eligible to appear in search while that directive remains in place.
An indexing review therefore asks a simple question: are the pages we want to appear in search actually eligible to do so?
For a deeper look at how these checks fit into a full audit, see our complete guide to technical SEO audits.
Site Speed and Core Web Vitals
Technical SEO isn’t only about whether search engines can access a website. The experience people have once they arrive matters too.
Core Web Vitals provide a useful way to assess key aspects of page experience:
- Largest Contentful Paint (LCP) — measures how quickly the main content becomes visible. A good score is 2.5 seconds or less.
- Interaction to Next Paint (INP) — measures how quickly a page responds to user interactions. A good score is 200 milliseconds or less.
- Cumulative Layout Shift (CLS) — measures unexpected movement of content while a page loads.
A technical SEO checklist should also look beyond the headline metrics. Large images, unnecessary JavaScript, third-party scripts and slow server responses can all contribute to a poor experience.
Practical checks include:
- Optimising images and serving appropriate formats.
- Reducing unnecessary JavaScript and CSS.
- Reviewing third-party scripts and their impact on performance.
- Improving server response times.
- Testing important page templates rather than relying only on the homepage.
- Monitoring performance using real-world user data where available.
web.dev provides detailed guidance on Core Web Vitals and how to measure them.
The goal isn’t simply to achieve a perfect score in a testing tool. It’s to identify performance problems that could affect how people use the site and address the issues that matter most.
Structured Data and Schema Markup
Search engines need to interpret the information on a page, not just access its HTML. Structured data can provide additional context about what that content represents.
Depending on the website, this could include information about products, organisations, articles, services, events or other supported content types.
Your technical SEO checklist should include:
- Checking whether relevant structured data has been implemented.
- Making sure the markup reflects the visible content on the page.
- Using the appropriate schema type for the content.
- Checking for errors and invalid properties.
- Reviewing structured data after major website changes.
Structured data doesn’t guarantee enhanced search results, but correctly implemented markup can help search engines understand the entities and information represented on a page.
You can explore the available vocabulary through Schema.org and use Google’s Rich Results Test where applicable to check whether eligible markup can be detected.
The important thing is not to add schema simply because it’s available. It should support the content and purpose of the page.
Mobile Performance and Security
A technically healthy website also needs to work reliably across devices and connections.
Your technical SEO checklist should include:
- HTTPS — check that secure connections are correctly implemented across the site.
- Mixed content — make sure secure pages aren’t loading important resources over HTTP.
- Mobile rendering — confirm that important content and functionality work properly on smaller screens.
- Readable content — text should be easy to read without unnecessary zooming.
- Interactive elements — buttons and links should be usable on touchscreens.
- Content consistency — important content shouldn’t disappear from the mobile version of a page.
These checks aren’t separate from SEO. A page that is difficult to use, slow to load or affected by security warnings can create a poor experience for visitors even when the underlying content is strong.
How to Use a Technical SEO Checklist
A checklist gives you a starting point, but it doesn’t tell you which issues deserve attention first. The aim is to understand what’s happening across the site, why it’s happening and what needs to be addressed.
1. Find the issue
Use crawling tools, Google Search Console, performance data and other relevant sources to identify problems across the website.
2. Understand the cause
Work out whether the issue affects one page, a specific template or the wider site. A problem affecting hundreds of URLs may need a very different solution from an isolated error.
3. Assess the impact
Prioritise issues affecting important pages, organic visibility or user experience. Not every warning generated by an SEO tool needs to be fixed immediately.
4. Fix the underlying problem
Address the cause rather than repeatedly treating the same symptoms. For example, correcting a template that generates incorrect canonical tags can be more effective than fixing individual URLs one at a time.
5. Monitor the result
Check that the fix worked and that it hasn’t created another issue elsewhere on the site. Technical SEO needs ongoing attention, particularly on websites that are regularly updated.
This is where a technical SEO audit checklist becomes more useful than a simple list of tasks. The goal isn’t to fix every warning a tool produces. It’s to understand which findings actually matter and turn them into practical actions.
Our complete technical SEO audit guide goes into the audit process in more detail, including crawling, crawlability, indexability, site structure, performance and other technical checks.
Preparing Your Website for AI Overviews
Search is changing, but the fundamentals of technical SEO haven’t disappeared.
AI Overviews and other search experiences need to retrieve and interpret information from web pages. That makes clear site architecture, accessible content and well-structured information increasingly important.
The answer isn’t to create a completely separate technical SEO checklist for AI. Start with the fundamentals:
- Make important content accessible to search engines.
- Keep your site structure logical.
- Use clear page-level signals.
- Implement structured data where it genuinely applies.
- Keep important information consistent and up to date.
- Avoid technical barriers that prevent pages from being properly accessed or understood.
In other words, AI search makes a strong technical foundation more useful, not less.
Your Technical SEO Checklist at a Glance
| Checklist area | What to check | Why it matters |
| Robots.txt, XML sitemap, internal links, status codes and redirects | Helps search engines discover important pages | |
| Noindex directives, canonicals, duplicate URLs and indexation status | Helps ensure the right pages are eligible for search | |
| 404 errors, crawl errors, redirect chains and URL consistency | Helps prevent technical issues from affecting access and signals | |
| LCP, INP, CLS, images, JavaScript and server response times | Supports a fast and responsive experience | |
| HTTPS, mobile rendering, mixed content and content consistency | Keeps the website accessible and reliable | |
| Relevant schema, valid implementation and updated markup | Provides search engines with additional context |
This checklist is a useful starting point, but a full review needs to consider how these areas interact across the website.
How SMP Approaches Technical SEO
Technical SEO shouldn’t be reduced to a report full of warnings and green ticks.
At SMP, we start by understanding the website, its goals and the issues that could be affecting organic performance. We then use the available data to identify problems, understand their impact and prioritise what needs attention first.
That means we’re not recommending changes simply because an SEO tool has flagged them. A technical issue needs to be considered in context: how widespread is it, which pages does it affect, and what difference could fixing it make?
Our approach can cover areas such as:
- Crawlability and indexation
- Site architecture and internal linking
- Technical migrations and redirects
- Core Web Vitals and website performance
- Structured data
- Mobile and security issues
- Technical SEO monitoring
Every website has its own history, technology and priorities, so the right technical SEO plan shouldn’t be based on a generic template.
If you want a clearer picture of what’s affecting your website, explore SMP’s technical SEO services.
Frequently Asked Questions
It covers the key areas that can affect how search engines access, understand and index a website. This includes crawlability, indexing, site health, Core Web Vitals, mobile performance, security and structured data.
The checklist can be useful for website owners, marketing teams, developers and SEO professionals who want to identify technical issues that could affect organic visibility. It’s particularly useful when launching, redesigning or migrating a website, or when organic performance isn’t meeting expectations.
SMP looks beyond the number of technical issues fixed. We assess whether the work has resolved important technical barriers, improved crawlability and indexability, and supported wider organic performance. The specific measures depend on the website, its goals and the issues identified.
A crawlability checklist focuses on whether search engines can discover and access your pages. An indexing checklist looks at whether those pages are eligible to appear in search and whether the correct versions are being selected.
Start with issues that could prevent important pages from being discovered, crawled or indexed. Check robots.txt, XML sitemaps, noindex directives, crawl errors, status codes and canonical tags before moving on to areas such as performance, structured data and mobile experience.