Google appears to Change Algorithm: Using Capital Letters Creates New Keywords

Written on May 7, 2008 – 12:18 pm | by bigoak |

Keyword research tools may be in for another overhaul.Google’s algorithm now appears to be viewing the capitalized versions of keywords as separate from the lowercase versions.I came across this while searching for the lowercase and uppercase versions of the keyword “engagement rings.”Look at these screen shots from the datacenter.

Screenshot of Google results with a lowercase “e” in engagement rings. Click for larger image.

Lowercase E

Screenshot of Google results with an uppercase”E” in Engagement rings. Click for larger image.


Searching with a capital “E” gives different results than searching with all lowercase letters, and I also noticed discrepancies between lowercase and uppercase letters with that keyword at the datacenter.

Now, look at the differences in the SERPS at the datacenter for the lower and uppercase version of the keyword “dog tags.”The results change after the second search result.

Screenshot of Google results with a lowercase “d” in dog tags. Click for larger image.

dog tags lower

Screenshot of Google results with an uppercase “D” in Dog tags. Click for larger image.

Dog Tags upper

Assuming this isn’t a temporary glitch, the SEO landscape will undergo another transformation.If this reflects a real change in the algorithm, keyword research tools such as Wordtracker and Keyword Discovery will have to be adjusted to compensate.They currently don’t differentiate between searches with lowercase and capital letters.Since the Google search results were believed to be identical for each, they had no reason to.

We’ll have to wait for an official word from Google (if they give one), but right now this is looking at lot less like a glitch and a lot more like a real shift in the algorithm. And it would be a significant one.I would guess that people search with different forms of capitalization as often as they misspell words or use theplural form of words.But it’s just a guess, as there is no keyword research data to back that assumption up….yet.

We’ll have to keep our eyes on this one.

  1. 28 Responses to “Google appears to Change Algorithm: Using Capital Letters Creates New Keywords”

  2. By Arnie on May 7, 2008 | Reply

    I’ve always wondered about this. I just conducted some a few searches with and without caps and the results did not seem to differ, but I only tried 3 different phrases.

    If what you are finding turns out to be true, you are right, the SEO world has something new to concentrate on. And just when I was beginning to cut my hours down to 16 per day :-)

  3. By Shell Harris on May 7, 2008 | Reply

    Arnie, you and I are in the same long-hours boat. I’m hoping this is only a temporary things. It’s hard enough with clients seeing different results due to Google datacenters but now we have to ask, “Are you using a uppercase or lowercase spelling?”

    By the way, I thought you have a lot of good information on your Auto Do Follow link post. You have great commenters! I am going to use some of that information for our auto dealer client.

  4. By Kiowa Jackson on May 8, 2008 | Reply

    I see different results when I search on a phrase with caps than I do without caps. But if I search a second time with caps the results go back to normal

  5. By Guy Thompson on May 10, 2008 | Reply

    I’ve noticed some differences in the lower reaches of the SERPs. Right now I’d say that the first 10% of results are probably identical, but that the lower pages can differ.

    Your mileage will vary.

    On a related topic, using hyphens in conjunction with capital letters in (for example) blog post titles and URLs might change the positioning in the SERPs, but again, there’s not much research to back it up.

    Experimentation will be the only way to be sure, but not many of us have the time!

  6. By Ash Nallawalla on May 10, 2008 | Reply

    Checked at,,, and while the total number of results for Engagement Ring (no quotes) is 7,160,000 and for engagement ring it is 7,140,000, the first 100 results for each are the same. Completely different results seen from Australia, e.g. the fourth result in both is a News item with Scarlett Johansson’s picture from the SF Chronicle.

    IOW, the observation could either be a glitch or a test that we are not seeing here.

  7. By Inkode SEO on May 15, 2008 | Reply

    There is currently a discussion about this on digital point:

  8. By Record Management on May 15, 2008 | Reply

    hopefully capitalization stuff doesn’t affect key wordage… otherwise I’m in for a world of hurt -_-

  9. By PA Internet Marketing on May 20, 2008 | Reply

    Yes I also notice the same, but you are right Will Paoletto for Google official words.

  10. By designer cufflinks on May 20, 2008 | Reply

    Wow, I didn’t notice that. Hope that this is just a temporary glitch, but if its not it will a lot of headache. Thanks for heads up.

  11. By A Tucson SEO on May 24, 2008 | Reply

    Thanks for the information in your article .I’m to do some searching of my own.

  12. By Southwest Rugs on May 25, 2008 | Reply

    Wow, never really noticed that capital letters changed the results. Thanks for the post, gonna try it out and see.

  13. By Tracy on May 29, 2008 | Reply

    This makes link building for some keyphrases really tough. Things that involve city names are a real toss up on whether they capitalize or not. This means twice as much link building.

  14. By Dave on Jun 1, 2008 | Reply

    I never knew about this. really gives a different results eh…will try on it. Thanks for the tips

  15. By John Barremore, SEO on Jun 2, 2008 | Reply

    I also noticed this discrepancy occurring about a couple of weeks back. The duality is especially apparent for sites online under a year. Though for clients with an Internet presence of 3+ years with stable positions it doesn’t appear to be an issue.

    …then again, I could be wrong. Who knows what’s really going on.

  16. By Hello on Jun 10, 2008 | Reply

    Great article. This is going to be interesting to follow because Googles URL’s are case sensitive as it is.

  17. By MWM on Jun 21, 2008 | Reply

    After reading this post, i came to realise that with or without a cap lock do make a difference in google search. Thanks for sharing info!

  18. By kevin on Sep 11, 2008 | Reply

    I feel it too…
    I see different results when I search on a phrase with caps than I do without caps. But if I search a second time with caps the results go back to normal

    I think it is because Google officials always say that google search algorithm is like human psychology and behavior and it try to show different and random results…

    So I think it when we search two three time with caps and small then we feel the difference in results…

  19. By Suresh on Sep 16, 2008 | Reply

    This is the happening this now. I would say that this might not be effecting us so much as most of the visitors on the search engines would not use capital letters. But lets hope this would not effect the SERP’s.

  20. By Mark on Oct 11, 2008 | Reply

    We’ll definitely have to watch this. The only constant with G seems to be that they are always changing. Rarely do they seem to stand still. I’ll run some tests on this later.

    Thanks for posting!

  21. By Jason on Oct 31, 2008 | Reply

    Now this is strange.. I’m assuming whether or not you use capitals in your title, meta tags and content can also affect your SERPS. This is pretty wild.

    Maybe using a variation of keywords that are both capital and lowercase when it makes sense is a good idea.

  22. By Antara on Jan 8, 2009 | Reply

    I don’t understand why Google would do this…since the intention of an user typing a letter in caps doesn’t differ much from the one not doing so..
    Any insights?

  23. By Will on Jan 11, 2009 | Reply

    @Antara, it can differ. There’s a difference between someone searching for Titanic, (the name of the ship or movie), and titanic, the adjective. If you search with a capitol “T,” you’re probably looking for the ship or movie. If you search with all lowercase letters, you may be looking for the definition of the adjective.

  24. By Antara on Jan 19, 2009 | Reply

    Yes.. I have to agree. You are right, it can differ :)
    Thanks for sharing :)

  25. By Christopher Regan on Feb 27, 2009 | Reply

    The ‘caps’ phenomenon is occurring again. Started two days ago, sadly.

  26. By Sandy on Mar 6, 2009 | Reply

    Yes there are some differences in google algorithm. Thanks or sharing the information. The Keysearch Analytics blog has tips, tricks, advice and case studies for the search marketing industry.

  27. By Im niche formula on Apr 14, 2009 | Reply

    This isn’t a very good system. Often people put the titles and headings of a site in capitals, but users search in lowercase

  28. By khalil on Apr 21, 2009 | Reply

    if your discovery is confirmed, it would be problem for web marketers who create tags and titles for websites… is there not a source to know about the google algorithm?

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  2. Jun 3, 2008: HELP: Why is PR different on URL when capitalized instead of Lowercase ? - WebProWorld

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