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.
How much impact does bad html coding really have on SEO?
- 
					
					
					
					
 My client has a site that we are trying to optimise. However the code is really pretty bad. There are 205 errors showing when W3C validating. The >title>, , <keywords> tags are appearing twice. There is truly excessive javascript. And everything has been put in tables.</keywords> How much do you think this is really impacting the opportunity to rank? There has been quite a bit of discussion recently along the lines of is on-page SEO impacting anymore. I just want to be sure before I recommend a whole heap of code changes that could cost her a lot - especially if the impact/return could be miniscule. Should it all be cleaned up? Many thanks 
- 
					
					
					
					
 Hi Chammy, I inherited a site that reported 3,184 crawl errors in MOZ and a significant number of them (nearly 600) were duplicate titles and content. I have that down to under 1,000 total errors and only 86 critical errors. I have seen my ranking grow pretty substantially and in one week had 6 pages increase over 20 positions in rank. I can share the MOZ Rank Report if you would like to see it. So yes, it does have an impact. 
- 
					
					
					
					
 I'm sorry, I don't have any evidence from the user experience point of view,. although I would also be interested to see the results of any studies. I will say that from a site management/maintenance point of view it makes sense to try and keep the code as clean as possible. I've been involved in project were a considerable chunk of the cost was incurred due to the amount of time and effort that was required to unravel the mess even before any new changes were made! 
- 
					
					
					
					
 Thanks very much everyone - very helpful. Good point re page speed - the pages are certainly slow to load so this could well be due to the huge amount of js and bad code. And yes, think the duplicate tags should be sorted - this shouldn't be difficult. Has anyone got any tangible results that they've seen as a result of cleaning up js and code? 
- 
					
					
					
					
 If you've got things like duplicate title and meta-description's going on then I'd certainly take a look at fixing those. Being able to manage these two tags is vital to managing the way your pages will appear in the search results. (And your title tag is an important ranking factor). Normally, if your page doesn't validate then it's not a major problem and search engines won't penalise you for it. If however, your page is so badly crafted that the html errors, and general page structure makes it difficult for the search engines (and humans) to read your page then you're going to suffer. The key is to make sure that your site/page content is accessible. How accessible is your page to someone with disabilities, using a screen reader etc. You've got to make sure that the search engines can understand what your page is about or your page won't be seen as a relevant page for any search terms... How bad is it? How does google render the page in it's instant previews (you can check this is Google Webmaster tools) 
- 
					
					
					
					
 I personally don't worry about bad code unless it slows down my page or can possibly make things confusing for search engines or readers. If the title and meta are appearing twice this could be confusing for search engines, so I would change this. But, if you've got things like an unclosed here and there I personally don't think that's going to be much of a factor. 
- 
					
					
					
					
 Invalid code has a small effect on ranking. However, if the invalid code causes usability issues such as load time and or causes a high bounce rate then it can lower your rankings and of course cut back on conversions. Some of it is a higher priority than others. I would say defo remove the meta keywords. Combine JS pages. The tables while out of date is not a big issue. If you have the time and resources then yes it should be cleaned up. If not then clean up major problems 
Browse Questions
Explore more categories
- 
		
		Moz ToolsChat with the community about the Moz tools. 
- 
		
		SEO TacticsDiscuss the SEO process with fellow marketers 
- 
		
		CommunityDiscuss industry events, jobs, and news! 
- 
		
		Digital MarketingChat about tactics outside of SEO 
- 
		
		Research & TrendsDive into research and trends in the search industry. 
- 
		
		SupportConnect on product support and feature requests. 
Related Questions
- 
		
		
		
		
		
		# Tag - opacity and SEO impact
 Hello, Technical SEO | | Tiffany_Barn
 I have a query animation 'fade-in-up' on my website: tiffanybarnard.com which moves the H1 tag slightly and fades it in from zero opacity to 1. Will this affect the SEO value of the H1 tag?
 Thank you!0
- 
		
		
		
		
		
		does <base> in html affect seo?
 hey, just wanna know does <base> in head of website affect SEO? and if it's a yes, how? Technical SEO | | m17001
- 
		
		
		
		
		
		Do long UTM codes hurt SEO?
 Since most UTM codes/URLs are longer than 70ish characters, is this hurting my SEO? If it is, how can I solve the problem while still using a UTM code? Thanks! Technical SEO | | Cassie_Ransom0
- 
		
		
		
		
		
		Is Removing Breadcrumbs Detrimental for SEO?
 We have full navigational breadcrumbs on our site for the menu and the brand menu. i.e. Home > Clothing > Jackets Brand > Brand Name > Brand Jackets There's been talk of removing this and having it like Chico's does, where on item pages they just have a link at the top to previous category (i.e. you're on a shirt product page and at the top it says "Back to Tops" instead of listing Home > Clothing > Tops) Is doing something like this detrimental to SEO? From what I've read Breadcrumbs are for user experience but I just want to be sure. Technical SEO | | AliMac260
- 
		
		
		
		
		
		Will removing the trailing slash impact my SEO?
 Hi there, We have a company website based on Wordpress. I just noticed that under Settings > Permalinks I can configure the look of the URLs and even remove the trailing slash. We have about 2-300 pages online. If I remove the trailing slash now, will that negatively impact our SEO in anyway for existing pages? Thanks! Technical SEO | | Amr-Haffar0
- 
		
		
		
		
		
		Sitmap Page - HTML and XML
 Hi there I have a domain which has a sitemap in html for regular users and a sitemap in xml for the spiders. I have a warning via seomoz saying that i have too many links on the html version. What do i do here? regards Stef Technical SEO | | stefanok0
- 
		
		
		
		
		
		Is link cloaking bad?
 I have a couple of affiliate gaming sites and have been cloaking the links, the reason I do this is to stop have so many external links on my sites. In the robot.txt I tell the bots not to index my cloaked links. Is this bad, or doesnt it really matter? Thanks for your help. Technical SEO | | jwdesign0
- 
		
		
		
		
		
		Root vs. Index.html
 Should I redirect index.html to "/" or vice versa? Which is better for duplicate content issues? Technical SEO | | DavetheExterminator0
 
			
		 
			
		 
			
		 
			
		 
			
		 
					
				 
					
				 
					
				 
					
				 
					
				 
					
				 
					
				