10 Mobile SEO Mistakes to Avoid in 2021 and Beyond

Is Your Mobile SEO Stuck in the Stone Age? Avoid These 10 Mistakes and Dominate Search Results Mobile users rule the web. But is your website stuck in the desktop era? Ranking high on search engines requires a mobile-first approach. This blog dives into 10 critical mobile SEO mistakes you MUST avoid to stay visible and win over mobile users. From slow loading times to bad website design, discover the culprits behind mobile SEO failure. Learn how to optimize Core Web Vitals, create user-friendly experiences, and leverage structured data for maximum impact. Don't let your mobile SEO be an afterthought. Take action today and ensure your website thrives in our mobile-driven world!



5/19/20216 min read

ext on phone screen about mobile SEO mistakes.
ext on phone screen about mobile SEO mistakes.

Ever since the notorious "mobilegeddon" back in 2015, Google has been preaching the significance of mobile-first indexing. What this basically means is that they are all about prioritizing and, in most cases, only giving attention to your mobile website when determining search rankings. So, even if your desktop site is top-tier, neglecting the optimization for mobile can seriously mess with your search visibility.

With Google's big move towards 100% mobile-first indexing in 2021, ensuring that your mobile experience is smooth has become more essential than ever. This includes keeping a close eye on Core Web Vitals, making sure your mobile content is optimized, and dealing with UX issues that are particular to mobile users.

Here are the top 10 mobile SEO mistakes that you need to sidestep. This will help you keep your website easily discoverable on search results, draw in more traffic, and keep those mobile users engaged:

Core Web Vitals: Slow Site Speed

A fast website is the key to succeeding in mobile SEO. Your pages should not only load quickly but users should also be able to interact with them immediately.

Page load speed is a crucial ranking factor, with two-thirds of Core Web Vitals directly dealing with site speed: Largest Contentful Paint (LCP) and First Input Delay (FID). Google's research also showcases that 53% of users will ditch pages that take longer than 3 seconds to load.

Optimizing your mobile site for speed entails:

  1. Minimizing requests and redirects: Keep your pages neat and streamlined. Get rid of unnecessary 301 redirects, remove extra elements, optimize HTML code, and minify elements like CSS and JavaScript that could slow loading.

  2. Resizing and compressing images: Take advantage of WordPress tools to automatically resize images and resources like compressor.io to minimize file sizes.

  3. Evaluating your hosting solution: Cheaper third-party hosting providers might not provide the speed required to handle large amounts of traffic, especially for e-commerce sites.

  4. Monitoring progress: Use Google's PageSpeed Insights or Lighthouse for a quick and easy evaluation of your website's performance.

  • Leveraging new web technologies: Use lazy loading methods to postpone loading of unnecessary or larger files until they are needed by the user.

Core Web Vitals: Intrusive Interstitials

In 2017, Google dropped the bomb that "pages where content is not easily accessible to a user on the transition from the mobile search results may not rank as high." While the impact on rankings was not massive at first, things have changed around.

Intrusive interstitials consist of pop-up ads, newsletter sign-up forms, and other banners that block user access to your website's content. Since 2021, this has partially merged into the Cumulative Layout Shift (CLS) metric.

CLS is part of Core Web Vitals, analyzing the overall layout shifts that happen on a page while it loads. This covers pop-ups shoving content down, interstitials shuffling content, and other user-unfriendly UX problems.

Websites bringing users a bad experience due to intrusive elements could see lower search rankings. This includes:

  • Pop-ups covering important content, whether they pop up upon landing from Google search results or as users scroll down the page.

  • Standalone, tricky-to-dismiss interstitials, especially those wrongly redirecting users to new pages when clicked.

  • Deceptive layouts where the above-the-fold section fools users into thinking they've stumbled upon an interstitial.

Missing Content: Blocked Files

Becoming a problem child in rankings can happen if there are huge gaps between your mobile and desktop sites. Googlebot, acting like a regular user, should be able to explore your entire website. Curtailing access to significant elements like JavaScript, CSS, and image files can mess with your search visibility.

Ensuring proper crawling of your mobile site involves:

  • Checking your robots.txt file: Confirm that no important elements are disallowed.

  • Testing your robots.txt file with Google Search Console.

  • Using Fetch by Google to spot any indexing problems and mobile-specific troubles using the mobile-friendly test.

  • Comparing both desktop and mobile URLs, not solely individual pages, to pinpoint differences.

Missing Content: Unplayable Content

Before injecting video or multimedia elements on your mobile site, think about their effect on loading speed and device compatibility. Plus, wherever possible, toss in transcripts to aid both Google (for indexing) and users who need closed captioning.

Missing Content: Bad Redirects and Cross-Links

Wonky redirects throw a major wrench in the works for websites without mobile optimization, particularly those with separate desktop and mobile URLs. Here's how you can take things up a notch:

  • Redirect mobile users who land on the desktop version to the equivalent mobile page, not your mobile homepage.

  • If no mobile equivalent for desktop pages exists, make it a priority to create them pronto. Until then, steer clear of redirecting users to your mobile homepage and keep them on the desktop page.

  • Mobile users aiming for dynamically generated URLs should be taken to corresponding mobile URLs that show the desired information.

  • Make sure mobile users across all devices access the same information.

  • Shy away from linking to desktop-optimized versions of your pages from mobile URLs.

The easiest fix to avoid these issues is to go with responsive website design over separate mobile and desktop domains. This strategy helps reduce common mislinking problems. Plus, verifying your mobile site with Google helps find mapping issues and crawl errors that can be fixed using Google Search Console.

Missing Content: Mobile-Only 404s

Much like the last point, users on both desktop and mobile versions of your website should be able to get at the same content. Google missing out on mobile content because it can't see it can do a number on your rankings.

So, tackle any occurrences where mobile users run into a 404 error when trying to access a page that's easily reachable by desktop users. Dodge linking to broken or missing content, and best practice would involve crawling your site using a mobile user-agent to spot any 404s.

Missing Content: Structured Data

Google is on a mission to serve users with rich, precise, and instant answers to their inquiries. Utilizing schema.org markup to classify your content can give you a significant edge in mobile search results.

If you're not yet seizing schema.org or Structured Data markup to categorize your content, you're missing out on a huge driver of organic CTR (click-through rate). Google and its users typically show love to rich snippets flaunting pertinent information that gels with search queries.

Bad UX: Not Specifying Mobile Viewport

Mobile screens come in assorted sizes and resolutions. If you don't specify the correct viewports using the viewport meta tag, users could find themselves on pages that are improperly scaled for their devices.

Bad UX: Poor Mobile Design

Many individuals confuse "mobile-first" with "mobile-friendly." While the former emphasizes Google prioritizing your mobile site for crawling and ranking, the latter signifies that your website is well-designed specifically for mobile devices.

You can be mobile-first without being mobile-friendly, but success in a mobile-first world requires a mobile-friendly approach. Therefore, design your website primarily for smartphones and tablets, not solely for the desktop experience.

Here are some key mobile design considerations:

  • Avoid illegible fonts, small font sizes, and excessive on-screen clutter.

  • Space page elements adequately to prevent mobile users from accidentally clicking the wrong link or button.

Responsive Strategies: Not Cross-Checking Metrics

It's crucial to understand how the tools you use daily function and how they calculate the metrics you rely on. Regardless of whether you're optimizing for mobile or desktop, utilize a reliable site auditing tool to identify potential gaps in your strategy.

This includes checking your content, links, title/meta tags, schema markup, and any other elements that contribute to your website's success. Ensure you're comparing desktop and mobile data to gain a comprehensive understanding of both versions.

Furthermore, recognize that even though different tools might offer similar functionalities (like site audits), they often yield measurably different results. Cross-check your results against another tool's findings, as you might be surprised by the discrepancies. Understanding how each tool arrives at its metrics is vital, allowing you to identify the numbers that matter most to your business and ultimately rely on the most relevant data.

Taking Action for Mobile SEO Success

The core principle of both desktop and mobile SEO lies in usability.

The foundation of any successful SEO strategy hinges on a thorough understanding of your target audience. This research should be the cornerstone of everything you do, encompassing SEO, content creation, website design, and other aspects. Understanding how consumers behave online allows you to tailor your approach and appeal to your audience effectively.

Failing to understand your customers can lead to numerous common SEO mistakes, including choosing irrelevant keywords, using headlines that don't address user pain points, or promoting on the wrong channels.


Getting your mobile SEO game on point is an ever-evolving process. Pay close attention to the user experience on your mobile site, address any potential issues that might hinder your rankings, and strive to create a seamless and engaging mobile experience for your visitors.

Remember, Google’s move towards mobile-first indexing is a clear indication that mobile optimization is no longer an afterthought but a critical component of any successful SEO strategy. By avoiding these common mobile SEO mistakes, you can ensure that your website remains visible in search results, attracts more traffic, and delivers a superior user experience on mobile devices.