An Easy Guide to Website Accessibility (Explaining All 46 Lighthouse Factors)

Adam Smartschan

Partner & Chief Strategy Officer

The web is the greatest information dissemination tool in the history of the world. Basically, it’s the Library of Alexandria times a million, in your pocket.

It’s critical to every piece of everyday life, from your commute to your job to your dinner. 

But what if you couldn’t use the internet? Or if parts of it were unavailable to you?

That’s why website accessibility is so important.

Website Accessibility graphic - building a site

Website accessibility isn’t just a set of standards or guidelines. It’s not just about “ADA compliance” or not getting sued. It’s about making your online work – the stuff you poured your heart and soul into – available to everyone. In short, it’s the right thing to do.

Here’s what you need to know about accessibility, how to check your site, and specific things to watch out for.

101 Guide to Website Accessibility

The standard in accessibility guidelines is the Web Content Accessibility Guidelines (WCAG), version 2.1.

WCAG 2.1 is pretty huge, but it boils down to one acronym: POUR. That is, content must be:

  • Perceivable
  • Operable
  • Understandable
  • Robust 

It’s not just about being OK for screen reader software, or having enough color contrast, or making your layout easy to follow. It’s all of that. 

There are multiple levels of accessibility standards: A, AA and AAA. They’re progressively more stringent – each has more rules than the last. 

It’s not possible to “partially” meet a WCAG level. You either do or you don’t. For most sites, we recommend shooting for AA compliance.

Checking Your WCAG Compliance

WebAIM provides a handy checklist for accessibility compliance, but the easiest way to quickly check your site is to use Lighthouse.

Lighthouse is an open source tool provided by Google meant to help developers improve user experience on their web properties. It’s broken down into four scores, which are likely fed into the Google algorithm. (Yes, accessibility can impact SEO.) The one you need to think about here is, naturally, Accessibility.

To check your site’s accessibility, head to, enter your URL and click “Run Audit.” The second score is the one to look for. It’s on a 1-100 scale. Most sites end up in the 60s or 70s out of the box; a select few – those that have focused on accessibility – are in the green, or 90+.

WCAG 2.1 Compliance Checklist

Lighthouse checks 35 individual website accessibility factors, and recommends a manual check of 11 more. Here they are.

Manual Website Accessibility Checks

Lighthouse advises you to look at these 11 website accessibility factors, but cannot check them automatically.

Adam Smartschan

Adam Smartschan heads Altitude's strategic marketing and branding efforts. An award-winning writer and editor by trade in a former life, he now specializes in data analytics, search engine optimization, digital advertising strategy, conversion rate optimization and technical integrations. He holds numerous industry certifications and is a frequent speaker on topics around B2B marketing strategy and SEO.