Google indexing influenced by Letter case

Has Google changed how it indexes based on lettercase and does it care about bounce rate anymore?

Google Webmaster LogoGoogle is always working to refine its search results with a renewed focus to reduce the impact of the Bing decision engine model with a move to evaluate and adjust results based on the users intention. One of the recent ones was noticed last month regarding local search results changing to suit the users letter case for a particular query but it seems that it may also be tested on all Google search results. With some of the many updates to Google Webmaster Tools it is now much more transparent and it is possible to get a better insight into keywords, pages indexed and what search queries will show which URLs from your website.

Google Webmaster Tools Changes?

The recent change to how Google has started to change its preference for lowercase versus uppercase urls showing in its search results which may also be trying to guess users intention based on emphasis of words.  Using one of my clients website data in Google Webmaster Tools the following points were noted regarding the preference for lowercase

  • not always preferred for low traffic terms
  • not dependant on single word search queries
  • did not depend on users search query letter case
  • very low traffic terms usually only indexed lowercase version
  • massive growth in organic traffic for lowercase versions

So looking at the Google cache to see if a lowercase and uppercase version were indexed showed only 1 version was available, but any that showed a preference for lowercase had a cache date of the 2nd May.  Some of the pages had a preference for the uppercase to be shown and these had a cache date of the 23rd March, which shows that the recent Mayday algorithm change affected more than just longtail keyword volumes but is also not yet fully implemented. Another question is do the uppercase and lowercase URLs showing up in the index, amount to duplicate content even after a recent update to the cached version of the 8th May, still can show both?

Which signals did Google use to select the letter case URL?

Lowercase signals

  • matched directory xml sitemap
  • no onsite links used the lowercase

Uppercase signals

  • onsite links used uppercase
  • primary xml sitemap used uppercase

So based on this it seems that the preference is likely decided by Googlebot as a change to the primary sitemap and onsite links that were using uppercase, did reduce the number of uppercase duplications showing but did not eliminate them completely.  The change to reducing the uppercase versions did show a large drop in Google Webmaster Tools in both impressions and clicks for a number of high traffic keywords, but might have been related to the Mayday update. Google continues to prefer to show the lowercase version of my clients URLs but still shows some of the uppercase versions within Google Webmaster Tools, but it seems you get more impressions and clicks if you have both versions included in the index. The URL data was from a period of approximately 10 days where both pages where showing in the search results and was taken from Google Analytics.

How does traffic to each case version differ?

Page 1 uppercase url = 161 visitors via 79 keywords (0.49 visitors/keyword)
Page 1 lowercase url = 927 visitors via 291 keywords (3.18 visitors/keyword)
Page 2 uppercase url = 33 visitors via 22 keywords (1.5 visitors/keyword)
Page 2 lowercase url = 162 visitors via 39 keywords (4.5 visitors/keyword)

Page case analysis: It seems that the lowercase was shown more times, and based on ratio the lowercase delivered a much higher number of visitors per keyword.  It is possible that this related to the uppercase might have shown up much lower in the search results.

How does the user behaviour of each case version differ?

Page 1 uppercase url
Bounce Rate 61.11%
Time on site: 1:45

Page 1 lowercase url
Bounce Rate 68.04%
Time on site: 1:46

Page 2 uppercase url
Bounce Rate 40%
Time on site: 1: 18

Page 2 lowercase url
Bounce Rate 54%
Time on site: 0: 48

Page Case Analysis: So it seems that the uppercase version appeared to perform significantly better based on the difficult metric of Bounce Rate compared to the lowercase version Google is preferring to show.  So does this mean that Google has changed how it calculates relevance and no longer considers bounce rate a valid metric for measuring user experience or is Google preferring people bounce back to the search results and do more searches?

4 Replies to “Google indexing influenced by Letter case”

  • this is a real problem with Hebrew wordpress blogs
    which uses /%category%/%postname%/ in permalink
    as Google seem to be stuck in a redirect due to the fact
    that Hebrew address are transformed into capital letters
    but wordpress changes them to lower case.

    i am stumped with such a problem now and would have
    to change permalink to something fixed such as p=123
    which does not include any keyword

    big big problem indeed

    • hmm… i’m not even sure how language might impact on this lowercase/uppercase issue but some of the answer above might help if not you might have to consider reaching out to another SEO agency who has experience in this language issue, try RustyBrick Web Services.

  • Interesting post have one question for you. What you will suggest if some of the URLs are uppercase and some are lowercase? Google only shows lowercase urls in its index. And the website have interlink from sidebar with uppercase url. What is your suggestion for this? Did one should use redirect and make all urls lowercase?

    • I have had to do this for one client’s website, it was a manual process of going through and changing the internal links. It can be a problem compounded by the hosting platform as .NET can be case specific so it can actually be a much bigger problem.

      I would try and force lowercase on the internal links manually that is much faster, but also ensure the CMS doesn’t change the case back after you publish it, the case settings are usually found in the advanced settings menus/area of the CMS admin console. Also you can look for htaccess help guides on this that can fix this issue.

      If you are using WP there are hacks you should be able to do as there are a limited number of plugins such as PermaLowercase

      If Google only wants to show lowercase, its easier to just accept this and adjust the site to use lowercase, but you have to be careful if you are using 301s as you might create a endless 301 loop.

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