What is Mobile SEO? 7 Ways to Improve SEO

What is Mobile SEO? 7 Ways to Improve SEO
Mobile SEO is a measure to improve a site's usability to be comfortably viewed on a Mobileand receive a high rating from Google, leading to improved search rankings. 

Google has adopted a Mobile-first index, which places more importance on Mobile-oriented sites than PC sites. 

Some items cannot be evaluated simply by making the site responsive to Mobileusing methods such as responsive. Let's check what criteria are used.

Overall Overview

When it comes to Mobile SEO, Google recommends addressing the following seven items

  1. Make text large enough to read
  2. Allow pages to be viewed by scrolling vertically
  3. Make links and buttons easy to press
  4. Don't Use Flash
  5. Display the same content on Mobile and PC
  6. Mutual redirection between Mobile and PC
  7. Place canonical link tag

1 through 4 are called "Mobile-friendly"; 

Google uses these four criteria to check whether a site is compatible with Mobile.

1. Make text large enough to read


Set the font size at 16px.

Google checks the font size of text

When indexing a page, Google checks whether the size of the text is appropriate. If the font size is small and difficult to read, the page is deemed "not Mobile-friendly.

Mobile-friendliness is a search ranking factor, and pages that are not Mobile-friendly will receive a negative rating.

Set the font size to an appropriate value

Set the font size to an appropriate value, including text such as notes and annotations.

Google recommends 16px as the font size for body text.

If the font size is too small, even after setting the font size, add the following meta tag so that the text is displayed at an appropriate size according to the screen size of a Mobile.

<meta name="viewport" content="width=device-width, initial-scale=1.0">

Use the Mobile Friendly Test Tool to find out if Google has deemed your site as Mobile friendly.

2. Allow pages to be viewed by scrolling vertically


Layout the page to fit the screen's width so that the entire page can be viewed without scrolling horizontally.

If a page can be scrolled horizontally, it is not Mobile-friendly

Images and tables that exceed the screen width of a Mobile phone cannot be viewed without scrolling horizontally or reducing the size of the page. 

Such horizontal scrolling operation is not comfortable from a usability standpoint, so Google will determine that "this page is not Mobile-friendly" as soon as it finds content that exceeds the screen width.

Set the maximum width of images and tables

Images and tables are the two most common things that can easily exceed the screen width on a Mobile site. 

It is most likely to occur when unusual large images are used or when tables with many columns or large amounts of text are described. Usually, this can be solved by writing the following CSS in advance.

img, table {
    max-width: 100%;


Avoid short, consecutive anchor text.

Google automatically determines the position of links and buttons

Since Mobileusers tap links and buttons with their fingers, it is easy for them to make mistakes if the buttons are small or if the links are close together. If Google finds a link or button that is "hard to press" or "easy to miss-press," it will consider the page "not Mobile-friendly.

Avoid anchor text that is too short

If the link text string is short, such as one to three characters in English, and if it is continuous, the link will be difficult to tap. 

Make the anchor text longer, or separate the lines if they cannot be longer.

Example 1Mobile-friendly link

<a href="...">src attribute</a> <a href="...">alt attribute</a>

Example 2Mobile-friendly links

  <li><a href="...">src</a></li>
  <li><a href="...">alt</a></li>

Example 3Not Mobile-friendly link (short anchor text)

<a href="...">src</a> <a href="...">alt</a>

4. Don't Use Flash


Use an alternative technology to Flash.

PC browsers no longer support Flash

Browsers for Mobiledo not support Flash, and browsers for PC no longer support Flash. Google considers Flash pages to be "not Mobile-friendly," which harms search rankings.

Replace it with an alternative technology

Today, Mobile and PC can achieve similar animations and UI with HTML 5 and CSS 3 without Flash.

Please refer to the following article for more information on Mobile-friendly support.

5. Display the same content on Mobile and PC


Do not differentiate the amount of information between Mobile and PC.

The same content is assumed for Mobile as for PC

It should not be desirable for users to see differences in the amount of information depending on the device used to view the site; Google also checks for differences in the amount of information by device, and recommends "the same content regardless of device.

Do not create separate HTML for Mobile and PC

Instead of creating different pages for Mobileand PC, use responsive or Mobile site libraries and use a single HTML.

When creating separate pages for Mobile phones and PC, ensure that the content is identical, even if the design is different.

6. Mutual redirection between Mobile and PC


If separate PC and Mobile pages exist, redirect to the page appropriate for the device.

Crawlers visit pages for PC and for Mobile

There are two types of search engine crawlers"PC crawlers" that patrol PC sites and "Mobilecrawlers" that patrol Mobilesites.

It is when the PC page and the Mobilepage exist separately. When the "crawler for Mobile" accesses the PC page, the crawler can discover the Mobilepage if it is redirected to the Mobilepage. 

Also, when a "PC crawler" accesses a Mobilepage, if it is redirected to a PC page, the crawler can discover the PC page.

Redirect to the appropriate page for each device

Even if you set up a link that says "Click here for the Mobilesite," the crawler cannot recognize that the destination is a Mobilepage.

Change the server settings to redirect to the Mobilepage when the PC page is accessed from a Mobilebrowser. Similarly, when a PC browser accesses a Mobilepage, redirect to the PC page.


Perform URL canonicalization and combine the ratings of PC and Mobile content.

Google evaluates similar content together

Search engines perform "URL normalization," or aggregation of similar content, before performing SEO evaluation. 

However, there are times when the automatic identification of similar content does not work correctly, which may result in a decrease in SEO evaluation.

Placing canonical link tag

The canonical tag is a tag that is responsible for telling search engines about canonical URL and can canonicalize the URL of similar content (duplicate content). 

canonical link tags specify the URL of PC pages.

<link rel="canonical" href="https://example.com/service/">


Mobile SEO is essentially about improving usability on Mobile.

To improve usability and display speed on Mobile, "Mobile-first," which puts the Mobilefirst, is helpful.

Since Google prioritizes the evaluation of Mobile sites over PC sites, Mobile-first is a natural progression in SEO.

To learn more about SEO, check out the post below.