What Is Mobile-First Indexing? A Comprehensive Guide

Mobile-first indexing is here to stay — and for good reason. Mobile devices dominate web traffic, which means businesses must keep up with the changing landscape of search engine optimization (SEO) to reach their target audiences successfully. One such change is the rise of mobile-first indexing.

So what is mobile-first indexing? In this post, we’ll explain what it means, its benefits, and how you can optimize your website for this important shift in SEO.

Mobile-First Indexing Definition

Mobile-first indexing means that search engine bots index the mobile version as the primary version of your website.

It’s essential to ensure your website is mobile-friendly for the sake of SEO and user experience. Your website should have a responsive design that can adjust to different screen sizes and load quickly on mobile devices.

Desktop-first indexing, which was the standard in the past, meant that results were ranked based on the desktop version of a website. However, the desktop version is now considered the “backup” option that comes second to mobile.

Evolution of Mobile-First Indexing

Mobile use grew in popularity over desktop sites in the mid-to-late 2000s. And these user habits and preferences helped change the landscape that led Google to adopt a mobile-first indexing policy.

In June 2014, the scales tipped in favor of mobile use versus a desktop site for the first time in history. Google was early to adopt a new “mobile-friendly” attitude in crawling and indexing.

The first sign was an article on the Google Webmaster Central blog from October 2009 titled “Let’s make the mobile web faster.” This was followed by tips to help mobile sites rank well according to the Google algorithm.

In November 2016, the Google blog announced the search engine’s future plans for mobile-first indexing. In March 202, Google announced that mobile-first indexing would be enabled by default for all new websites starting July 1, 2021, indicating a complete shift to mobile-first indexing.

However, in March 2021, Google delayed the mobile-first indexing deadline for existing websites to March 2023 due to the impact of the COVID-19 pandemic, giving webmasters additional time to prepare their sites.

Importance of Mobile-First Indexing

Why should you care about optimizing your mobile pages? Here’s a look at the top benefits of mobile-first indexing.

• Improved User Experience: Google ranks websites based on their mobile versions, so optimizing your mobile site leads to better rankings and an enhanced experience for mobile users.
• Better Google Search Rankings: Mobile-first indexing prioritizes mobile content and considers page speed, leading to higher search rankings.
• Enhanced Mobile Traffic: Mobile-first indexing increases mobile traffic by making your site more visible and user-friendly to those on a mobile device, resulting in higher conversions and sales.
• Optimized for the Future: Mobile-first indexing is a long-term strategy essential for businesses as mobile usage continues to rise.
• Competitive Edge: Embracing mobile-first indexing gives your business a competitive advantage by reaching a wider audience and increasing your customer base.

Keep in mind that mobile and desktop versions should be comparable — so if you optimize one, you should optimize the other too.

How Mobile-First Indexing Works

Now that you know the benefits of mobile-first indexing, let’s take a look at how it works.

Google’s Crawling and Indexing Process

To show a website in its search results, Google sends bots called “crawlers” to gather information for Google’s index. The traditional desktop index used these bots to crawl desktop versions. Now, the smartphone Googlebot crawls the site’s mobile version as the main iteration that requires indexing.

Your role is to direct these crawlers to the correct information on your website. This is done by having the appropriate XML sitemaps and robots.txt files. Sitemaps rank the pages in order of importance and give extra information, like modification dates and how often changes are made.

Robot.txt files tell the mobile user agent which pages to crawl and index and which to skip. This helps prevent duplicates and low-quality pages from being indexed.

Determining Mobile-Friendliness

To determine your website’s mobile-friendliness, there’s a mobile-friendly test made available by Google Search Console. It gives you a verdict of your website’s usability on mobile, which is the starting point for optimizing your mobile site.

Here are the key factors that determine mobile-friendliness:

Responsive Design

Responsive design means the web design of desktop and mobile versions of your website is the same and seamlessly works on different devices. This requires the inclusion of adaptive CSS, JavaScript, and HTML.

Page Load Speed

You can expect a mobile page to load slower than a desktop page, but minimizing the gap helps boost your website’s mobile friendliness.

Content Accessibility

Avoiding elements that can’t be viewed on mobile devices helps make for a mobile-friendly version of your website.

Ranking Factors for Mobile-First Indexing

Mobile-first indexing ranks some websites better than others based on the following criteria:

Mobile Usability

Mobile usability means the mobile site is accessible to the smartphone Googlebot. The Google Search Console URL testing tool checks if your website uses separate mobile and desktop URLs and crawls both versions. Mobile usability doesn’t mean the website design is mobile-friendly, though.

Page Speed and Load Time

Having a slow load time for your mobile site can highly affect its ranking. If the mobile version of your website lags or crashes, this spells trouble for how well the Googlebot can access it. Practices like “lazy-loading” a web page can help create more responsive sites that don’t take forever to load.

Mobile Content and Structured Data

Ensuring your website’s desktop and mobile versions have the same content can do wonders for mobile rankings.

This also applies to having the same structured data and images that spell the website’s layout to crawlers. For example, recipe ingredients, directions, and calorie content headings in a cooking blog help search engines look for specific data when prompted.

Mobile-Specific Metadata

Website metadata helps crawlers index and rank a page by offering page titles, keywords, and descriptions. A mobile site should have the same metadata as the desktop site, besides mobile-specific meta robots tags that help offer the mobile version to a mobile browser.

Best Practices for Mobile-First Indexing

To give your mobile site a leg up in the mobile-first indexing race, here are some practices to put into mind:

Responsive Web Design

Opting for responsive design on your website has innumerable benefits. These include more mobile traffic, easier and less-expensive development and maintenance, and better search engine ranking.

A cornerstone practice of responsive design is CSS media queries, meaning any content rendering adapts to different conditions, like screen resolution, for example. This approximates content availability for both mobile and desktop sites.

Flexible grids and layouts that don’t have a declared number of rows or columns also make for a smoother experience navigating your website on mobile.

Mobile Page Speed Optimization

Fast loading time on a mobile site isn’t just a luxury. It directly affects the website’s “crawlability” and determines whether Googlebot can index the pages or struggle through the process.

You can measure page speed through multiple developer tools, such as PageSpeed Insights, GTMetrix, and WebPage Test.

You can also use one of the following optimization techniques that can vastly improve mobile page speed to match or even exceed the desktop version of your website:

• Minify CSS, JavaScript, and HTML: Remove unnecessary characters from files to reduce their size.
• Optimize Images: Resize and compress images to occupy a smaller space on the webpage for the mobile version.
• Leverage Browser Caching: This process controls how long a guest’s mobile browser stores images, JS, and CSS files on the device. Downloading less data at a time makes the pages load faster.

Content Optimization

A huge part of optimizing your mobile and desktop site versions is consistent content across devices. Having an abridged version for your mobile site spells SEO trouble because the pages indexed for mobile-first indexing don’t contain enough information.

You should also improve the readability on mobile devices by increasing font sizes (no smaller than 32p) and using highly contrasting colors for the font and background.

Properly formatted headings and subheadings can also boost your SEO ranking thanks to structured data markup. And as for the use of multimedia and visual elements, they help make your website more visually interesting instead of having walls of text.

Mobile SEO Techniques

To target users visiting your website on mobile, you should consider doing some mobile-specific keyword research while building content. This ensures the mobile version of your site is ranking high enough to garner clicks.

Another important factor in mobile SEO is voice search optimization. Optimizing for voice search results can be done by targeting long-tail keywords and questions and using conversational language in your content.

This ties in with local search optimization if you run a business you want to redirect traffic toward, online and offline. Claim your Google Business Profile and keep your mobile site updated. For instance, the next time someone asks Alexa, “Where’s the nearest pet supply store?” your business could come up first.

Common Mobile-First Indexing Issues and Solutions

Here are some hurdles you might face while adapting your mobile site to mobile-first indexing and how to address each.

Inaccessible or Hidden Content on Mobile

One of the things that can hurt your website’s ranking is inaccessible or hidden content (aka black hat SEO tactics). This was a trick that websites used to optimize for SERPs back when search engines were text-based. However, doing so can get your website penalized or even taken off SERPs.

Ensuring all content is accessible and visible to the user means you don’t hide content via CSS on the mobile version. It also means avoiding shady practices like cloaking, which can get your website blacklisted.

Avoid any use of Flash and other outdated technologies that can appear as desktop and mobile errors. This is best practice even if you consider the desktop site to be the primary version of your website.

Unplayable Videos

Current HTML5 video standards support three formats: Mp4, Ogg, and WebM. However, you should keep in mind that support for these formats varies among mobile and desktop browsers.

While Mp4 is almost universal, Firefox browsers disable it by default. WebM lacks support in some browsers, and Ogg isn’t supported by Safari. This issue can lead to videos being unplayable on your mobile site, depending on the guest’s browser.

One way to circumvent this problem is by providing video transcripts. This not only gives your mobile guests a way of accessing the unplayable content but also allows crawlers to index the transcript text.

Intrusive Interstitials and Pop-ups

One of the most rewarding mobile-first best practices is following Google’s guidelines on interstitials. These are defined as page elements meant to obstruct the page view, often including a call-to-action, like an email signup or app download.

Some alternative solutions for promotions and calls-to-action can be found in un-intrusive dialog boxes. These include banners and smaller-sized interstitials.

Whatever you do, don’t completely hide the page with interstitials or redirect users to a separate page for signups or giving consent.

Final Thoughts

Mobile-first indexing ensures a better user experience. Now that we’ve answered the question of “What is mobile-first indexing?” you know it’s a significant change in SEO you must pay attention to stay competitive in the digital marketplace.

A mobile-optimized website will increase website traffic, visibility, and conversions. You’ll also want to ensure users have a great experience on your desktop site for the highest rankings.

Ensure your website design is responsive and loads quickly on mobile devices. By doing so, you’ll be in a good position to benefit from this SEO update and stay ahead of the competition.