The Ultimate Technical SEO Checklist: Errors, Warnings, and Optimization Opportunities

Technical SEOBy Marketers.pkUpdated 2026-10-1426 min read

Technical SEO refers to optimizing a website’s backend aspects to improve its search engine visibility and performance. It focuses on elements such as site structure, indexing, crawling, page speed, and mobile compatibility, which are crucial for search engines to access and rank a website properly. Unlike on-page SEO, which involves content optimization like keywords and meta tags, technical SEO ensures that the website’s infrastructure is sound and efficient. Both are essential for boosting rankings, but technical SEO handles the behind-the-scenes mechanics, ensuring smooth functioning and accessibility. This makes technical SEO a critical part of an overall SEO strategy.

Key takeaways

A technical SEO checklist covers crawling, indexing, HTTPS, redirects, sitemaps, speed and mobile setup so search engines can reach and rank your pages (list reviewed October 2026).
Fix errors first: 5xx and 4xx responses, broken links, blocked pages, invalid robots.txt or sitemaps, and TLS or certificate problems.
Warnings such as temporary redirects, missing alt text, uncompressed files and long titles come next; none of these are 'penalties', they are ranking or user-experience weaknesses.
Add the checks crawlers miss: JavaScript rendering, the Crawl stats and robots.txt reports in Search Console, AI crawler rules and HTTP/2 or HTTP/3.
Legacy items like AMP canonicals, frames, Flash plugins, text-to-HTML ratio and underscores in URLs can usually be ignored.

Why Technical SEO is Important

Technical SEO is crucial in enhancing a website’s performance in search results. It’s not just about doing the right things; it’s about doing them efficiently. Improving crawlability and indexing ensures that search engines can efficiently navigate and display your site, making it more likely to appear in search results. Optimizing page speed, mobile-friendliness, and site architecture leads to a better user experience, reducing bounce rates and boosting engagement.

A technically optimized site also has an advantage over competitors, many of whom neglect this aspect. Ultimately, technical SEO builds a strong foundation, supporting the long-term success of both on-page and off-page SEO efforts and making your SEO efforts more productive and effective. This checklist was last reviewed in October 2026; items that no longer matter have been moved to a short legacy note near the end.

Errors

Technical errors can significantly hinder your website’s performance and visibility in search engines. Identifying and fixing these issues is critical to maintaining a healthy site that ranks well and provides a seamless user experience. Below, we break down common technical SEO errors, their causes, and actionable solutions to address them.

5xx Errors

Problem: These server-side errors (e.g., 500, 503) occur when the server is unable to fulfill a request due to a malfunction or overload.
Impact: Users can’t access the website, causing poor user experience and loss of rankings as search engines can’t crawl the affected pages.
Solution: Check server logs for specific causes, increase server capacity, or contact hosting providers for support.

4xx Errors

Problem: Client-side errors (e.g., 404 not found) occur when a user or search engine requests a page that doesn’t exist or can’t be accessed.
Impact: Poor user experience, wasted crawl budget, and potentially lost rankings for linked pages.
Solution: Set up 301 redirects for moved pages or create a custom 404 page to guide users.

Missing Title Tags

Problem: Pages without title tags are missing key metadata used by search engines to understand content.
Impact: Reduced SEO performance and poor click-through rates in search results.
Solution: Ensure all pages have unique and descriptive title tags.

Duplicate Title Tags

Problem: Multiple pages have identical title tags, causing confusion for search engines.
Impact: Difficulty ranking the correct page, leading to potential keyword cannibalization.
Solution: Write unique title tags for each page that reflect its content.

Duplicate Content

Problem: Same or very similar content appears on multiple pages or across different domains.
Impact: Search engines may pick the wrong version to rank and split signals between the copies, leading to lower rankings.
Solution: Use canonical tags to indicate the preferred version of a page or remove duplicate content.

Broken Internal Links

Problem: Internal links point to non-existent or moved pages.
Impact: Bad user experience, wasted crawl budget, and lost ranking signals.
Solution: Regularly audit and fix broken internal links.

Pages Not Crawled

Problem: Pages are not accessible to search engine crawlers, possibly due to restrictions in robots.txt or server issues.
Impact: Pages won’t appear in search results, limiting visibility and traffic.
Solution: Check crawl settings in robots.txt and Google Search Console, and resolve server issues.

DNS Resolution Issue

Problem: The domain name system (DNS) is unable to resolve, meaning the browser cannot find the website’s IP address.
Impact: Users can’t access the site, leading to downtime and potential loss of traffic.
Solution: Check DNS settings and work with the hosting provider to resolve any configuration issues.

We Couldn’t Open the Page’s URL

Problem: Search engine crawlers cannot access a specific page.
Impact: Search engines can’t index the page, reducing its visibility.
Solution: Verify that the page is accessible, check for errors like 403 (forbidden) or 404, and ensure proper permissions.

Broken Internal Images

Problem: Images on the website are missing or fail to load due to incorrect file paths or deletion.
Impact: Poor user experience and negative impact on visual content engagement.
Solution: Audit the site for missing images and update file paths or re-upload them as needed.

Duplicate Meta Descriptions

Problem: Multiple pages have identical meta descriptions.
Impact: Search engines struggle to differentiate between pages, potentially reducing click-through rates.
Solution: Write unique, compelling meta descriptions for each page.

Invalid Robots.txt Format

Problem: The robots.txt file is improperly formatted, leading to miscommunication with search engines.
Impact: Crawlers may unintentionally block important pages or resources.
Solution: Check the file in Search Console’s robots.txt report, test rules with our free robots.txt tester, and correct any errors.

Invalid Sitemap.xml Format

Problem: The sitemap.xml file contains errors, making it unreadable for search engines.
Impact: Search engines may miss important pages when crawling the site.
Solution: Run the file through our free sitemap validator and correct the errors.

Incorrect Pages Found in Sitemap.xml

Problem: The sitemap contains pages that shouldn’t be indexed (e.g., old or duplicate content).
Impact: Crawlers waste time and resources, reducing the efficiency of indexing important pages.
Solution: Update the sitemap to include only relevant and indexable pages.

www Resolve Issues

Problem: The website is accessible through both www and non-www versions without proper redirects.
Impact: Can lead to duplicate content issues and diluted SEO efforts.
Solution: Set up a 301 redirect from one version to the other to ensure consistency.

Viewport Not Configured

Problem: No viewport meta tag is set, making the site unoptimized for mobile devices.
Impact: Poor mobile user experience and weaker mobile rankings.
Solution: Add a viewport tag in the HTML to make the site responsive.

Large HTML Page Size

Problem: Pages have excessively large HTML sizes, slowing down loading times.
Impact: Poor user experience, increased bounce rates, and lower search rankings.
Solution: Optimize the HTML by minifying code and removing unnecessary elements.

Issues with Hreflang Values

Problem: Incorrect or missing hreflang values cause problems for international SEO.
Impact: Search engines may serve the wrong language version of your site to users.
Solution: Correct hreflang values to ensure the right language and region version appears for each user.

Hreflang Conflicts Within Page Source Code

Problem: Conflicting hreflang tags within the page’s source code confuse search engines.
Impact: Reduced international ranking and traffic due to improper targeting.
Solution: Fix any conflicts and ensure hreflang values are consistent.

Issues with Incorrect Hreflang Links

Problem: Incorrect hreflang links point to the wrong URLs.
Impact: Search engines may misinterpret regional targeting.
Solution: Audit hreflang links and fix incorrect URL values.

Non-Secure Pages

Problem: Pages are served over HTTP instead of HTTPS.
Impact: Weaker rankings, browser security warnings, and user trust issues.
Solution: Migrate all pages to HTTPS.

Certificate Expiration

Problem: SSL certificate has expired.
Impact: Browser warnings, blocked access to the website, and lost traffic.
Solution: Renew the SSL certificate with your hosting provider.

Old Security Protocol Version

Problem: The site still accepts outdated protocols such as SSL 3, TLS 1.0 or TLS 1.1.
Impact: Vulnerability to attacks and browser warnings.
Solution: Enable TLS 1.2 and 1.3 and disable older versions in the web server or control panel.

Certificate Registered to Incorrect Name

Problem: The SSL certificate does not match the website domain.
Impact: Browser warnings and potential security risks.
Solution: Obtain an SSL certificate for the correct domain name.

Issues with Mixed Content

Problem: Pages load both secure (HTTPS) and insecure (HTTP) elements.
Impact: Browser security warnings and a weaker page experience.
Solution: Update all resources (images, scripts) to load over HTTPS.

Neither Canonical URL Nor 301 Redirect From HTTP Homepage

Problem: No canonical URL or 301 redirect is set from the HTTP version of the homepage to the HTTPS version.
Impact: SEO issues and duplicate content risks.
Solution: Set up a 301 redirect from the HTTP homepage to the HTTPS version.

Redirect Chains and Loops

Problem: Multiple redirects in a sequence or an infinite loop.
Impact: Slower load times and wasted crawl budget, leading to poor SEO performance.
Solution: Simplify redirects to a single step, and fix any looping issues.

Broken Canonical URLs

Problem: Canonical tags point to non-existent or incorrect URLs.
Impact: Confuses search engines and can cause indexing issues.
Solution: Fix broken canonical URLs to point to valid pages.

Multiple Canonical URLs

Problem: Multiple canonical URLs are specified for a single page.
Impact: Causes search engines to misinterpret which version is the main one.
Solution: Ensure only one canonical URL is set for each page.

Meta Refresh Redirects

Problem: Pages use meta refresh tags to redirect instead of server-side 301 redirects.
Impact: Confuses search engines and users, and is slower and less reliable than a server redirect.
Solution: Use 301 redirects instead of meta refresh tags.

Broken Internal JavaScript and CSS Files

Problem: JavaScript and CSS files are missing or broken.
Impact: Poor page functionality and user experience, potentially hurting rankings.
Solution: Audit and fix broken script or stylesheet paths.

Insecure Encryption Algorithms

Problem: The server still offers weak TLS cipher suites or old protocol versions during the HTTPS handshake.
Impact: Security vulnerabilities, browser warnings, and user trust issues.
Solution: Enable TLS 1.2 and 1.3 with modern cipher suites, disable TLS 1.0 and 1.1, and test the server with SSL Labs.

Too Large Sitemap.xml

Problem: Sitemap.xml file exceeds size limits (50 MB or 50,000 URLs).
Impact: Search engines may not fully crawl or index the sitemap.
Solution: Split the sitemap into smaller files and link them in a sitemap index.

Malformed Links

Problem: Links on the website are incorrectly formatted or broken.
Impact: Negative user experience and lost link equity.
Solution: Regularly check and fix malformed or broken links.

Invalid Structured Data Items

Problem: Structured data on the page is incorrectly formatted or missing required fields.
Impact: Rich search result features may not appear, lowering visibility.
Solution: Validate structured data using Google’s Rich Results Test or the Schema Markup Validator and correct any errors.

Viewport Width Not Set (Same Fix as Viewport Not Configured)

Problem: Semrush lists this separately, but it is the same missing or incomplete viewport meta tag as above.
Impact: The same as above: poor mobile user experience and weaker mobile rankings.
Solution: Use <meta name="viewport" content="width=device-width, initial-scale=1"> once in the head of every page.

Slow Page (HTML) Load Speed

Problem: HTML pages take too long to load due to large file sizes or server issues.
Impact: Higher bounce rates, poor user experience, and lower search rankings.
Solution: Optimize code, compress resources, and improve server response times.

Addressing these errors will improve your site’s functionality, ensure search engines can efficiently crawl and index your pages, and enhance user experience, leading to better search rankings and performance.

Warnings

Warnings indicate potential areas of concern that, while not immediately critical, could impact your website’s SEO and usability if left unresolved. These are opportunities to fine-tune your site’s technical setup and ensure optimal performance in search results.

Broken External Links

Problem: External links point to non-existent or unreachable web pages.
Impact: Reduces user trust and may impact SEO if search engines crawl these broken links.
Solution: Regularly audit and update or remove broken external links.

Broken External Images

Problem: External images fail to load due to broken URLs or removed files.
Impact: Poor user experience and potential negative impact on the visual appeal of your content.
Solution: Ensure all external image URLs are valid and consider hosting important images locally.

Links Lead to HTTP Pages for HTTPS Site

Problem: Internal or external links direct users to HTTP pages while your site uses HTTPS.
Impact: Security warnings in browsers and a possible drop in rankings due to mixed content.
Solution: Update all links to point to the HTTPS versions of the pages.

Short Title Element

Problem: Title tags are too short and fail to adequately describe the page content.
Impact: Missed SEO opportunities and reduced click-through rates.
Solution: Write descriptive, keyword-optimized titles that are at least 50–60 characters.

Long Title Element

Problem: Title tags are too long and may be truncated in search results.
Impact: Lower visibility in SERPs and potential miscommunication of content relevance.
Solution: Ensure title tags are concise, around 50–60 characters, including keywords.

Missing H1

Problem: The page lacks an H1 header, which is crucial for content structure and SEO.
Impact: Search engines may struggle to understand the main topic of the page.
Solution: Add a clear and relevant H1 tag that reflects the page’s primary focus.

Duplicate Content in H1 and Title

Problem: The content in the H1 tag is identical to the title tag.
Impact: None with Google; an identical H1 and title is fine. At most it is a missed chance to phrase the headline differently.
Solution: Optional. Vary the H1 wording if a different headline reads better on the page; otherwise ignore this warning.

Missing Meta Description

Problem: No meta description is present, leaving search engines to generate one automatically.
Impact: Missed opportunity to control how your page is described in SERPs, potentially reducing click-through rates.
Solution: Write unique, engaging meta descriptions for each page to improve SEO and encourage clicks.

Too Many On-Page Links

Problem: The page contains an excessive number of links.
Impact: Dilutes link equity and overwhelms users, leading to poor user experience.
Solution: Audit and reduce the number of on-page links to focus on the most important ones.

Temporary Redirects

Problem: Temporary (302) redirects are used instead of permanent (301) redirects.
Impact: Search engines may not transfer SEO value properly, leading to lower rankings.
Solution: Replace temporary redirects with 301 redirects when permanent page moves are intended.

Missing ALT Attributes

Problem: Images lack ALT text, which is used to describe images for search engines and visually impaired users.
Impact: Missed SEO opportunities and accessibility issues.
Solution: Add relevant ALT attributes to all images.

Too Many URL Parameters

Problem: URLs contain numerous parameters, which can cause issues for search engines.
Impact: Search engines may struggle to index the content properly, and tracking parameters could be confusing.
Solution: Simplify URLs by reducing parameters and using SEO-friendly URL structures.

Missing Hreflang and Lang Attributes

Problem: The page lacks hreflang and lang attributes that specify the language and region targeting.
Impact: Search engines may not display the correct language version of your page to users in different regions.
Solution: Add hreflang and lang attributes to specify language and regional targeting.

Encoding Not Declared

Problem: The page does not declare a character encoding standard.
Impact: Browsers may not display the content correctly, leading to usability issues.
Solution: Declare the correct character encoding, such as UTF-8, in the page’s HTML header.

Doctype Not Declared

Problem: The HTML document does not declare a DOCTYPE.
Impact: Browsers may render the page incorrectly, affecting user experience and accessibility.
Solution: Add the correct DOCTYPE declaration at the beginning of the HTML document.

Low Word Count

Problem: Pages have insufficient content to be deemed valuable by search engines.
Impact: Lower rankings and decreased relevance for targeted keywords.
Solution: Add meaningful, high-quality content to each page.

Frames Used

Underscores in URL

Nofollow Attributes in Outgoing Internal Links

Problem: Internal links are marked with a nofollow attribute, which prevents search engines from following them.
Impact: Wasted link equity and reduced crawl efficiency.
Solution: Remove nofollow attributes from internal links unless there is a specific reason to block search engines from following them.

Sitemap.xml Not Specified in Robots.txt

Problem: The robots.txt file does not specify the location of the sitemap.xml.
Impact: Search engines may miss the sitemap, leading to inefficient crawling.
Solution: Add the sitemap location to the robots.txt file.

Sitemap.xml Not Found

Problem: No sitemap.xml file is available for the website.
Impact: Search engines may struggle to discover and index all pages efficiently.
Solution: Create and submit a sitemap.xml file to search engines.

HTTPS Encryption Not Used

Problem: The website does not use HTTPS encryption.
Impact: Lower rankings, potential browser security warnings, and reduced user trust.
Solution: Implement an SSL certificate to secure the site and use HTTPS for all pages.

No SNI Support

Problem: The server does not support Server Name Indication (SNI), which allows multiple SSL certificates on the same IP address.
Impact: HTTPS may not work properly for some users.
Solution: Upgrade the server to support SNI.

HTTP URLs in Sitemap.xml for HTTPS Site

Problem: Sitemap.xml contains HTTP URLs for a website that uses HTTPS.
Impact: Confusing search engines and creating security issues.
Solution: Update all URLs in the sitemap to use HTTPS.

Uncompressed Pages

Problem: Pages are not compressed, leading to slower load times.
Impact: Poor user experience and lower search engine rankings due to slow performance.
Solution: Enable Gzip or Brotli compression on the server to reduce page size.

Blocked Internal Resources in Robots.txt

Problem: Critical internal resources (like CSS or JavaScript files) are blocked in the robots.txt file.
Impact: Search engines may not fully understand or render the page correctly.
Solution: Remove unnecessary blocks from the robots.txt file.

Uncompressed JavaScript and CSS Files

Problem: JavaScript and CSS files are not compressed, leading to slower page load times.
Impact: Poor user experience and potentially lower rankings due to slow performance.
Solution: Compress JavaScript and CSS files using Gzip or Brotli.

Uncached JavaScript and CSS Files

Problem: JavaScript and CSS files are not cached, causing longer load times on repeat visits.
Impact: Reduced user experience and slower load times, impacting SEO.
Solution: Implement caching for these files to improve performance.

Too Large JavaScript and CSS Total Size

Problem: The combined size of JavaScript and CSS files is too large, leading to slow loading times.
Impact: Increased load times negatively affect user experience and SEO.
Solution: Minimize and combine JavaScript and CSS files where possible.

Too Many JavaScript and CSS Files

Problem: The page loads an excessive number of JavaScript and CSS files.
Impact: Increases page load times, hurting user experience and rankings.
Solution: Combine and minimize files to reduce the number of requests.

Unminified JavaScript and CSS Files

Problem: JavaScript and CSS files are not minified, which adds unnecessary weight to the page.
Impact: Slower load times and poor SEO performance.
Solution: Minify these files to remove excess code and reduce page size.

Too Long Link URLs

Problem: URLs are excessively long, often containing unnecessary parameters or elements.
Impact: Poor user experience and reduced SEO efficiency, as shorter URLs tend to perform better.
Solution: Simplify and shorten URLs by removing unnecessary characters or parameters.

By resolving these warnings, you can fine-tune your website’s SEO, avoid potential pitfalls, and ensure that your site performs well in both search engine rankings and user engagement.

Notices

Notices highlight minor issues or areas for improvement that, while not urgent, can affect your website’s overall SEO and user experience if left unchecked. By addressing these notices, you can optimize your site further and prevent these minor issues from escalating into more serious problems.

Multiple H1 Tags

Problem: A page contains more than one H1 tag, which can confuse search engines about the page’s primary focus.
Impact: May dilute the SEO value of the primary H1 tag and reduce the clarity of the page’s structure.
Solution: Ensure each page contains only one H1 tag that accurately reflects the content’s main topic.

Blocked from Crawling

Problem: Some pages or resources are blocked from being crawled by search engines, either by robots.txt or meta tags.
Impact: Search engines cannot index or rank blocked content, reducing visibility.
Solution: Review robots.txt and meta tags to ensure important content is not unintentionally blocked.

URLs Longer than 200 Characters

Problem: URLs are excessively long, often including unnecessary parameters or lengthy descriptions.
Impact: Long URLs can be difficult for users to read and may negatively affect SEO.
Solution: Shorten URLs by removing unnecessary parameters and creating concise, descriptive URLs.

Nofollow Attributes in Outgoing External Links

Problem: External links are marked with a nofollow attribute, preventing search engines from following these links.
Impact: None for your own rankings. Nofollow on an external link only tells Google not to treat the link as your endorsement of that site.
Solution: Keep nofollow (or sponsored and ugc) for paid, user-submitted or untrusted links, and leave normal editorial links to trusted sources as plain links.

Robots.txt Not Found

Problem: The website does not have a robots.txt file.
Impact: Search engines may waste resources crawling unimportant or restricted pages, leading to inefficient indexing.
Solution: Create a robots.txt file to guide search engines on which pages to crawl and which to ignore.

Hreflang Language Mismatch Issues

Problem: Hreflang tags need to match language or region codes.
Impact: Search engines may serve the wrong language version of a page to users, reducing the relevance of your content.
Solution: Correct the hreflang values to match the intended language and region.

No HSTS Support

Problem: The website does not use HTTP Strict Transport Security (HSTS), which enforces the use of HTTPS.
Impact: Users may still access the site over HTTP, potentially causing security risks and lower trust.
Solution: Enable HSTS to ensure all users are directed to the HTTPS version of your site.

Orphaned Pages (Google Analytics)

Problem: Pages that receive visits in Google Analytics have no internal links pointing to them. Semrush shows this only when GA4 is connected; without Semrush, export your GA4 page list or sitemap and compare it with a Screaming Frog crawl.
Impact: Orphaned pages may not be easily discoverable by users or search engines, reducing their visibility.
Solution: Ensure all pages are linked within the site to improve internal linking and crawlability.

Orphaned Sitemap Pages

Problem: Pages listed in the sitemap are not linked to other pages on the website.
Impact: Search engines may find these pages through the sitemap, but they could still be considered low-value due to the need for internal links.
Solution: Add internal links to these pages to improve crawlability and user access.

Blocked by X-Robots-Tag: noindex HTTP Header

Problem: The X-Robots-Tag blocks Pages from indexing in the HTTP header.
Impact: Search engines will not index these pages, preventing them from appearing in search results.
Solution: Review the X-Robots-Tag settings and unblock any pages that should be indexed.

Blocked External Resources in Robots.txt

Problem: External resources like CSS or JavaScript files are blocked in the robots.txt file.
Impact: Search engines may not be able to render pages properly, which could impact rankings.
Solution: Unblock critical external resources in the robots.txt file to ensure proper rendering.

Broken External JavaScript and CSS Files

Problem: External JavaScript or CSS files are missing or broken.
Impact: This can affect the functionality and appearance of your website, leading to a poor user experience.
Solution: Replace or fix the external JavaScript and CSS files to restore functionality.

Page Crawl Depth More than 3 Clicks

Problem: Pages are buried deep within the website, requiring more than three clicks.
Impact: Pages too far from the homepage may not be crawled frequently or rank well.
Solution: Flatten the site structure by linking important pages closer to the homepage.

Pages with Only One Internal Link

Problem: Some pages are linked from only one other page on the site.
Impact: These pages may receive less link equity and are harder for users and search engines to discover.
Solution: Add more internal links to these pages to increase their visibility and SEO value.

Permanent Redirects

Problem: The site uses permanent (301) redirects, which are correctly implemented but should be regularly reviewed.
Impact: While 301 redirects pass link equity, too many redirects can slow down performance.
Solution: Regularly audit redirects and eliminate any unnecessary chains or loops.

Resources Formatted as Page Links

Problem: Non-page resources (e.g., PDFs, images) are linked as HTML pages.
Impact: Misleading anchor text and expectations can lead to poor user experience.
Solution: Clearly label non-page resources and consider embedding or handling them differently.

Links with No Anchor Text

Problem: Links on the page have no anchor text at all.
Impact: Search engines rely on anchor text to understand link relevance so that missing text can hurt SEO.
Solution: Add meaningful anchor text to all links to improve clarity and SEO.

Links with Non-Descriptive Anchor Text

Problem: Links use generic text like “click here” or “read more” instead of descriptive keywords.
Impact: Missed opportunities to provide context for both users and search engines.
Solution: Replace non-descriptive text with keyword-rich, relevant anchor text.

External Pages or Resources with 403 HTTP Status Code

Problem: External pages or resources return a 403 (forbidden) status code, which is inaccessible.
Impact: Users and search engines cannot access these external resources, affecting user experience.
Solution: Check the external resources or contact the website owners to resolve access issues.

This collection of notices reflects potential issues that are generally less severe but should still be addressed to maintain good SEO practices and a strong user experience. Regular auditing and proactive maintenance will help prevent these issues from becoming more critical.

Core Web Vitals and the Order to Fix Issues

Most audit tools flag slow pages, but Google measures real-user experience with three Core Web Vitals. Check them in the Core Web Vitals report in Google Search Console and in PageSpeed Insights.

Metric	What it measures	Good score
LCP (Largest Contentful Paint)	How fast the main content loads	2.5 seconds or less
INP (Interaction to Next Paint)	How fast the page responds to taps and clicks	200 milliseconds or less
CLS (Cumulative Layout Shift)	How much the layout jumps while loading	0.1 or less

INP replaced FID in March 2024, so ignore older guides that still talk about First Input Delay.

Field data versus lab data

The scores that count for ranking are field data: measurements from real Chrome users, collected in the Chrome User Experience Report (CrUX). PageSpeed Insights shows them at the top of its report, and Search Console groups URLs by them. The Lighthouse score lower down is a lab test on one simulated device and is only a guide. A page with little traffic has no field data of its own; PageSpeed Insights then falls back to origin-level data for the whole site, and if the site is also small you will see "no data". In that case fix what the lab test and your own phone show, and note that Google simply has no Core Web Vitals signal for that page, good or bad.

A simple priority order

Indexing blockers: 5xx errors, robots.txt blocks, noindex tags and DNS problems.
Security and redirects: HTTPS, expired certificates, TLS versions, redirect chains and loops.
Duplicates: canonical tags, www and non-www versions, duplicate titles.
Speed: Core Web Vitals, image sizes, compression and caching.
Clean-up: notices such as orphaned pages, deep pages and weak anchor text.

Work through one group at a time, recrawl, and confirm the fix before moving on.

Checks Most Crawlers Miss (Added October 2026)

The errors, warnings and notices above come from what a crawler can see. These checks need Search Console or a look at the server, and they catch problems that crawl reports do not.

JavaScript rendering. If your site is built on React, Vue, Next.js or a page builder that injects content with scripts, inspect a key page with the URL Inspection tool in Search Console and open "View crawled page". If the rendered HTML is missing your text, links or products, Google is missing them too. Server-side rendering or pre-rendering fixes it.
Crawl stats report. In Search Console under Settings, the Crawl stats report shows how often Googlebot visits, how many requests end in errors and how long responses take. A rising error rate or response times over a second point to hosting problems that no audit tool reports.
robots.txt report. Search Console's robots.txt report (added in 2023, replacing the old tester) shows the file Google last fetched, when, and any parse errors. Check it after every deployment, and test rules before you publish with our free robots.txt tester.
AI crawler rules. Decide deliberately which AI crawlers may fetch your pages. GPTBot (OpenAI), ClaudeBot (Anthropic), PerplexityBot and others honour robots.txt. Google-Extended only controls use for Gemini training; it does not affect Google Search or AI Overviews, so blocking it will not remove you from AI Overviews. Blocking everything can cost you citations in AI answers; allowing everything costs bandwidth. Most businesses allow the major ones.
HTTP/2 or HTTP/3. Confirm your host serves pages over HTTP/2 at least (most Pakistani shared hosts and Cloudflare do). It lets browsers load many files over one connection, which makes the "too many JavaScript and CSS files" warnings far less important than they were under HTTP/1.1.
hreflang via sitemap. For a site with English and Urdu versions, hreflang annotations in the XML sitemap are easier to keep consistent than tags in every page's head. Search Console no longer has an International Targeting report, so validate with a crawler or our sitemap validator.
Index status of key pages. Use the Page indexing report, and spot-check a batch of URLs with our Google index checker.

Legacy Issues You Can Usually Ignore

Audit tools still report some items that stopped mattering years ago. Do not spend time on these unless a developer has a specific reason:

AMP canonical tags. AMP has had no ranking advantage since Google's 2021 page experience change. If you still serve AMP pages, the better fix is to retire them and 301 them to the normal pages.
Frames and framesets. Almost no modern site uses them; if one of your pages does, rebuild it rather than tune it.
Incompatible plugins (Flash, Java, Silverlight). Browsers dropped support long ago. Replace the content with HTML5 or video.
Text-to-HTML ratio. Google has said this is not a ranking factor. Heavy pages matter for speed, which Core Web Vitals already measure.
Underscores in URLs. Hyphens are the convention, but Google handles both. Do not redirect existing URLs just to swap underscores for hyphens; the redirects cost more than the underscores.
Identical H1 and title. Fine with Google. Vary them only if a different headline reads better.

Conclusion

Addressing the technical aspects of SEO is crucial to ensuring your website performs at its best for users and search engines. By resolving errors, addressing warnings, and proactively managing notices, you can maintain a healthy, high-performing website that ranks well and provides a seamless user experience.

To uncover and resolve these issues, various site audit tools are available. Popular tools like SEMrush Site Audit, Ahrefs Site Audit, and Screaming Frog can help you identify technical SEO problems, monitor your site’s health, and guide your optimization efforts. Regularly auditing your website with these tools will keep your SEO on track and help you avoid potential issues before they impact your rankings and traffic.

More Technical SEO guides

Frequently asked questions

How often should I run a technical SEO audit?

Run a full technical SEO audit at least once a quarter, and after any redesign, migration, theme change or big plugin update. Small sites that rarely change can manage with a crawl every few months. Busy e-commerce sites should schedule weekly crawls, because new products, filters and out-of-stock pages create fresh errors all the time. Check Google Search Console weekly in between.

What is the difference between technical SEO and on-page SEO?

Technical SEO makes sure search engines can crawl, render and index your site: server responses, redirects, HTTPS, sitemaps, robots.txt, speed and mobile setup. On-page SEO improves the content of each page: titles, headings, keywords, internal links and meta descriptions. Both matter. Great content cannot rank if the page is blocked or broken, and a fast, clean site still needs useful content.

Can I do a technical SEO audit for free?

Yes. Google Search Console is free and shows indexing problems, Core Web Vitals, HTTPS status, crawl stats, robots.txt fetches and manual actions. PageSpeed Insights tests speed for any URL. Screaming Frog SEO Spider has a free version that crawls up to 500 URLs, which is enough for most small business sites, and marketers.pk offers free robots.txt, sitemap, redirect, schema and on-page checkers. Paid tools like Semrush and Ahrefs add scheduled crawls, history and larger limits.

Which technical SEO issues should I fix first?

Fix anything that stops pages being crawled or indexed first: server errors, pages blocked in robots.txt, stray noindex tags and broken HTTPS. Next, clean up redirects, duplicate content and canonical tags. Then work on speed and Core Web Vitals. Leave notices like long URLs or non-descriptive anchor text for last, unless they affect your most important pages.

#Google Search Console #Site Audit #Redirects