Skip to content
    Moz logo Menu open Menu close
    • Products
      • Moz Pro
      • Moz Pro Home
      • Moz Local
      • Moz Local Home
      • STAT
      • Moz API
      • Moz API Home
      • Compare SEO Products
      • Moz Data
    • Free SEO Tools
      • Domain Analysis
      • Keyword Explorer
      • Link Explorer
      • Competitive Research
      • MozBar
      • More Free SEO Tools
    • Learn SEO
      • Beginner's Guide to SEO
      • SEO Learning Center
      • Moz Academy
      • MozCon
      • Webinars, Whitepapers, & Guides
    • Blog
    • Why Moz
      • Digital Marketers
      • Agency Solutions
      • Enterprise Solutions
      • Small Business Solutions
      • The Moz Story
      • New Releases
    • Log in
    • Log out
    • Products
      • Moz Pro

        Your all-in-one suite of SEO essentials.

      • Moz Local

        Raise your local SEO visibility with complete local SEO management.

      • STAT

        SERP tracking and analytics for enterprise SEO experts.

      • Moz API

        Power your SEO with our index of over 44 trillion links.

      • Compare SEO Products

        See which Moz SEO solution best meets your business needs.

      • Moz Data

        Power your SEO strategy & AI models with custom data solutions.

      Track AI Overviews in Keyword Research
      Moz Pro

      Track AI Overviews in Keyword Research

      Try it free!
    • Free SEO Tools
      • Domain Analysis

        Get top competitive SEO metrics like DA, top pages and more.

      • Keyword Explorer

        Find traffic-driving keywords with our 1.25 billion+ keyword index.

      • Link Explorer

        Explore over 40 trillion links for powerful backlink data.

      • Competitive Research

        Uncover valuable insights on your organic search competitors.

      • MozBar

        See top SEO metrics for free as you browse the web.

      • More Free SEO Tools

        Explore all the free SEO tools Moz has to offer.

      NEW Keyword Suggestions by Topic
      Moz Pro

      NEW Keyword Suggestions by Topic

      Learn more
    • Learn SEO
      • Beginner's Guide to SEO

        The #1 most popular introduction to SEO, trusted by millions.

      • SEO Learning Center

        Broaden your knowledge with SEO resources for all skill levels.

      • On-Demand Webinars

        Learn modern SEO best practices from industry experts.

      • How-To Guides

        Step-by-step guides to search success from the authority on SEO.

      • Moz Academy

        Upskill and get certified with on-demand courses & certifications.

      • MozCon

        Save on Early Bird tickets and join us in London or New York City

      Access 20 years of data with flexible pricing
      Moz API

      Access 20 years of data with flexible pricing

      Find your plan
    • Blog
    • Why Moz
      • Digital Marketers

        Simplify SEO tasks to save time and grow your traffic.

      • Small Business Solutions

        Uncover insights to make smarter marketing decisions in less time.

      • Agency Solutions

        Earn & keep valuable clients with unparalleled data & insights.

      • Enterprise Solutions

        Gain a competitive edge in the ever-changing world of search.

      • The Moz Story

        Moz was the first & remains the most trusted SEO company.

      • New Releases

        Get the scoop on the latest and greatest from Moz.

      Surface actionable competitive intel
      New Feature

      Surface actionable competitive intel

      Learn More
    • Log in
      • Moz Pro
      • Moz Local
      • Moz Local Dashboard
      • Moz API
      • Moz API Dashboard
      • Moz Academy
    • Avatar
      • Moz Home
      • Notifications
      • Account & Billing
      • Manage Users
      • Community Profile
      • My Q&A
      • My Videos
      • Log Out

    The Moz Q&A Forum

    • Forum
    • Questions
    • Users
    • Ask the Community

    Welcome to the Q&A Forum

    Browse the forum for helpful insights and fresh discussions about all things SEO.

    1. Home
    2. SEO Tactics
    3. Intermediate & Advanced SEO
    4. Is DOCTYPE important for SEO?

    Moz Q&A is closed.

    After more than 13 years, and tens of thousands of questions, Moz Q&A closed on 12th December 2024. Whilst we’re not completely removing the content - many posts will still be possible to view - we have locked both new posts and new replies. More details here.

    Is DOCTYPE important for SEO?

    Intermediate & Advanced SEO
    2
    2
    4751
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as question
    Log in to reply
    This topic has been deleted. Only users with question management privileges can see it.
    • AdeLewis
      AdeLewis last edited by

      Hello fellow Mozzers.

      I am just having a brief look at a potential clients website before speaking to them tomorrow and whilst looking at the source I noticed that they don't appear to have a clear definition for their Doctype.

      All the have at the top of each page is

      I have to admit that Doctypes aren't my strong point but I know that they are normally slightly more descriptive than this.

      Can this have any effect on rankings? or is this just an issue for W3C validation?

      Thanks 🙂

      1 Reply Last reply Reply Quote 0
      • SL_SEM
        SL_SEM last edited by

        If it is an HTML 5 page that should be just fine as it is the HTML 5 doctype tag.

        Check out the info here: http://www.w3schools.com/html5/tag_doctype.asp

        It might cause trouble with really old browsers, but if they have that going I would hope they have already thought about the reasons for and against using it 🙂

        EDIT: even better link: http://www.w3.org/TR/html5-diff/#doctype

        1 Reply Last reply Reply Quote 1
        • 1 / 1
        • First post
          Last post

        Got a burning SEO question?

        Subscribe to Moz Pro to gain full access to Q&A, answer questions, and ask your own.


        Start my free trial


        Browse Questions

        Explore more categories

        • Moz Tools

          Chat with the community about the Moz tools.

        • SEO Tactics

          Discuss the SEO process with fellow marketers

        • Community

          Discuss industry events, jobs, and news!

        • Digital Marketing

          Chat about tactics outside of SEO

        • Research & Trends

          Dive into research and trends in the search industry.

        • Support

          Connect on product support and feature requests.

        • See all categories

        Related Questions

        • dailynaukri

          Do self referencing links have any SEO importance?

          Intermediate & Advanced SEO | | dailynaukri
          0
        • Muhammad-Isap

          How important is admin-ajax.php?

          Hi there! It's been a long time since I last did a technical audit of a site. I've currently playing with the 'fetch as google' tool to find out if we're blocking anything vital. The site is based on Wordpress, and after a recent hacking incident, a previous SEO moved the login portal from domain.com/wp-admin/ to domain.com/pr3ss/wp-admin/ - to stop people finding it. Fair enough. But they then updated the robots.txt file to look like this: User-agent: *
          Disallow: /pr3ss/wp-admin/ Now, some pages are trying to draw on theme elements like: http://www.domain.com/pr3ss/wp-admin/admin-ajax.php
          http://www.domain.com/pr3ss/wp-content/themes/bestpracticegroup/images/column_wrapper_bg.png And are naturally being blocked (not that this seems to affect the way pages are rendering in Google's eyes) A good SEO friend of mine has suggested allowing the theme folder, and any sub folders where this becomes an issue. What are your thoughts? Is it even worth disallowing the /pr3ss/wp-admin/ path? Cheers guys and gals! All the best, John. I've found a couple of the theme's

          Intermediate & Advanced SEO | | Muhammad-Isap
          0
        • nicole.healthline

          How important are sitemap errors?

          If there aren't any crawling / indexing issues with your site, how important do thing sitemap errors are? Do you work to always fix all errors? I know here: http://www.seomoz.org/blog/bings-duane-forrester-on-webmaster-tools-metrics-and-sitemap-quality-thresholds Duane Forrester mentions that sites with many 302's 301's will be punished--does any one know Googe's take on this?

          Intermediate & Advanced SEO | | nicole.healthline
          0
        • cre8

          How important is the number of indexed pages?

          I'm considering making a change to using AJAX filtered navigation on my e-commerce site.  If I do this, the user experience will be significantly improved but the number of pages that Google finds on my site will go down significantly (in the 10,000's). It feels to me like our filtered navigation has grown out of control and we spend too much time worrying about the url structure of it - in some ways it's paralyzing us.  I'd like to be able to focus on pages that matter (explicit Category and Sub-Category) pages and then just let ajax take care of filtering products below these levels. For customer usability this is smart.  From the perspective of manageable code and long term design this also seems very smart -we can't continue to worry so much about filtered navigation. My concern is that losing so many indexed pages will have a large negative effect (however, we will reduce duplicate content and be able provide much better category and sub-category pages). We probably should have thought about this a year ago before Google indexed everything :-).  Does anybody have any experience with this or insight on what to do? Thanks, -Jason

          Intermediate & Advanced SEO | | cre8
          0
        • MangoMan16

          Changing Servers + Effect on SEO

          Hi, I am currently with a very slow server. Our website takes quite a while to load, FTP is very slow and content changes with Wordpress are slow because even the database connection takes a lot of time. However, my website ranks very well. Traffic has doubled in the last year. Our domain has been registered with this company for over 10 years. I am wondering if changing to a different hosting provider would have an effect on my rankings due to the change in IP.

          Intermediate & Advanced SEO | | MangoMan16
          0
        • kashyaplakkad

          What should I cover in a SEO proposal ?

          What should I cover in a SEO proposal? Is there any sample SEO Proposal template in SEOMoz?

          Intermediate & Advanced SEO | | kashyaplakkad
          1
        • kchandler

          URL Shorteners. Are they SEO Friendly?

          Do URL shortener services like bit.ly act as 301 redirects? I was thinking about utilizing one for longer query based URLs and didn't want to risk losing link juice. Thanks for the insight! Regards - Kyle

          Intermediate & Advanced SEO | | kchandler
          0
        • VividLime

          Link Age as SEO factor?

          Hi Guys
          I have a client who ranks well within a competitive sector of the travel industry. They are planning CMS move which will involve changing from .cfm to .aspx We will be doing the standard redirects etc However Matt's statement here on 301 redirects got me thinking
          http://www.youtube.com/watch?v=zW5UL3lzBOA&t=0m24s He says that basically you loose a bit of page rank when you do a 301 redirect. Now, we will be potentially redirecting 1000s of links and my thinking is 'a lot of a little, adds up to a lot'  In other words, 1000s of redirects may have a big enough impact to loose some rankings in a very competitive and aggressive space. So recommended that we contact the sites who has the link highest value and ask them to manually change the links from cfm to aspx. This will then mean that there are no loss value as with a 301 redirect. -But now I have another dilemma which I'm unsure about. So the main question:
          Is link age factor in rankings ? If I  update any links, this will make said link new to Google, so if link age is a factor, would this also lessen the value passed initially?

          Intermediate & Advanced SEO | | VividLime
          0

        Get started with Moz Pro!

        Unlock the power of advanced SEO tools and data-driven insights.

        Start my free trial
        Products
        • Moz Pro
        • Moz Local
        • Moz API
        • Moz Data
        • STAT
        • Product Updates
        Moz Solutions
        • SMB Solutions
        • Agency Solutions
        • Enterprise Solutions
        • Digital Marketers
        Free SEO Tools
        • Domain Authority Checker
        • Link Explorer
        • Keyword Explorer
        • Competitive Research
        • Brand Authority Checker
        • Local Citation Checker
        • MozBar Extension
        • MozCast
        Resources
        • Blog
        • SEO Learning Center
        • Help Hub
        • Beginner's Guide to SEO
        • How-to Guides
        • Moz Academy
        • API Docs
        About Moz
        • About
        • Team
        • Careers
        • Contact
        Why Moz
        • Case Studies
        • Testimonials
        Get Involved
        • Become an Affiliate
        • MozCon
        • Webinars
        • Practical Marketer Series
        • MozPod
        Connect with us

        Contact the Help team

        Join our newsletter
        Moz logo
        © 2021 - 2025 SEOMoz, Inc., a Ziff Davis company. All rights reserved. Moz is a registered trademark of SEOMoz, Inc.
        • Accessibility
        • Terms of Use
        • Privacy

        Looks like your connection to Moz was lost, please wait while we try to reconnect.