Why Your Website Code is Important for SEO

Optimising PerformanceI’m just completing an SEO review on the website of a local business, and I thought it may be helpful to talk generally about some of the major points that came out.

Don’t fret – total confidentiality is guaranteed!

First thing to keep in mind: Search Engine Optimisation is a dynamic environment.

The search engines constantly update their algorithms to provide more relevant results and stay ahead of the black-hatters.

Plus, developments in technology enable them to continually use new and more effective methods of discovering what your site is about.

None-the-less, some core principles hold true:

Web users want sites that load quickly, are easy to navigate, provide good information and are clearly laid out.

So do the search engines.

Consider that for a moment, and you’ll realize that this means more than just good content and good META tags.

It means your entire site construction must be efficient and clean. Here’s why:

Use of images

Among the things that slow down site load times are, of course, too many images that are too large.

I’ve seen sites that use images to portray information that should be in H1 or H2 headers.

Not only does this slow down the site load time but, unless you provide informative descriptions in your ‘alt’ tags, the search engines won’t know what information you’re putting across – because they can’t read images.

Not good for SEO.

Wherever you use images be sure to complete informative ‘alt’ and ‘title’ tags. And use images to support your message, not to give it.

Multiple versions and types of code


HTML has evolved through a number of versions to XHTML. Because of this there’s a doc type declaration at the top of each page that tells the browser which version of HTML or XHTML you’re using.

This enables the browser to render your site quickly and accurately.

I’ve seen sites that declare XHTML in the doc type but then use earlier versions of HTML (as well as XHTML) in the body content.

This will slow down site load times as the browser will take longer to figure out what you’re trying to display. On some browsers it may well create errors.

It will also reduce your cross-browser compatibility, meaning that your site will render completely differently in some browsers – potentially destroying your carefully designed layout.

Ensure that your site is consistently built, using the version of HTML (or XHTML) that you define in your doc type declaration. This will speed up site load times and improve cross-browser compatibility.

Good for SEO

Tables versus CSS

I’ve seen new sites (developed as recently as last year) built using tables, but with blocks of CSS definitions and JavaScripts in the HEAD section.

This, again, will slow down site load times and reduce cross-browser compatibility.

No new site should use tables in its construction.

CSS was developed to separate the design from the content. The styling of your site should be done in a stylesheet and kept in a separate file.

This will speed up site load times because all the style rules need only be downloaded once, instead of each time a page is downloaded. The external stylesheet will ensure styling is displaid consistently throughout your site.

It also improves cross-browser compatibility by reducing the amount of code on the web page and defining the styling in accordance with the agreed CSS standards.

Reducing the amount of code on a page (thereby improving the ratio of content to code) will help the search engines to read your site and understand what it’s about.

Good for SEO


We’ve all known for a long time that the search engines’ aim is to provide the most relevant results possible. Therefore, good content was important if you wanted to do well in the search results.

But other factors are coming into play all the time, and site load-time is a recent one.

So, in addition to all the things I’ve written about before (good content, correct META tags, proper use of H tags, alt tags and title tags, etc), you need to pay close attention to things that will affect site load times and consistent rendering.

Which means making sure your code is up to scratch.


Martin Malden

What do you think?

Comments on this entry are closed.

  • Eric Buckley May 11, 2010 @ 12:25

    Very nice, succinct post Martin. All very good contributing factors towards SEO and good visitor experience.

    I recently posted a more technical aspect of the same topic.

    Google has stated that Site load time will become a significant contributor to ranking. They have introduced a tool in the Webmaster Tools “Labs” section that Webmasters can review to understand the current speed issues with their site.
    .-= Eric Buckley’s last blog post: Protecting Your Online Identity =-.

    • Martin May 11, 2010 @ 15:03

      Thanks, Dude, and thanks for the Retweet as well..!



  • Angiel May 14, 2010 @ 2:22

    Martin – I don’t know how many books I’ve read on SEO, so finally your simple plain English is refreshing!

    I’m curious though – when content is almost exclusively Images, will a theme like Thesis really help?

    Or is SEO for artists just generally much more difficult?
    .-= Angiel’s last blog post: Hide And Seek =-.

    • Martin May 14, 2010 @ 7:00

      Hi Angie,

      If your content is exclusively images then you need to make sure you use image ‘alt’ tags on each image – and make them full and descriptive.

      That will enable the search engines to get the clearest idea possible what each image and, therefore, the page is about.

      The current version of Thesis will help in that you can insert your META Title, Description and Keywords tags for each article individually (just as you can with the All-in-one-SEO-pack) and you can set up site-wide META tags as well.

      Setting up these tags (as well as the image ‘alt’ tags) for each article will definitely improve the SEO effectiveness of the articles (and site).



  • seo May 27, 2010 @ 11:22

    Yes ,i am agree with your opinion. The search Engine always update their algorithm. So, if we concentrate all this tips , I think SEO will be better.

  • Ayden Mar 2, 2011 @ 8:40

    Hi Martin,

    Great advice. I totally agree with Tables versus CSS

    • Martin Mar 2, 2011 @ 10:02

      Ayden, hi,

      Yes – it’s amazing that people are still using tables in new sites..!

      It’s also pretty amazing that the various browsers manage to sort those sites out and render them – not always as the site owner intended, true, but rendered none-the-less.