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5 most common website accessibility failings, according to the WebAIM Million analysis

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The WebAIM Million is an accessibility analysis of homepages from the top 1,000,000 websites, first carried out in February 2019. A second analysis, published in August, suggests that disabled people are excluded in the current state of online accessibility.

The WebAIM Million analysis uses WAVE stand-alone API, a tool developed by WebAIM, to test for website accessibility problems. The WAVE tool flags patterns in web page content that align with end user accessibility issues. These issues are defined by the Web Content Accessibility Guidelines (WCAG). Each issue raises a potential problem for people using assistive technology. This includes screen readers and text-to-speech (TTS) software.

These results automatically generate and measure the number of detectable issues according to WCAG.

Read more about the WAVE accessibility tool in our article ‘6 quick tools web developers can use to test for accessibility

What is the WebAIM Million 6-month re-analysis?

The study uses the top million websites to test the state of online accessibility. These ‘top’ million websites are informed by the Majestic Million. This tool, created by Majestic SEO, indexes link data about websites with the most referring subnetworks or other websites. The more backlinks and referrers a site has, the more important Majestic SEO considers it. At the top of the Majestic million are sites from Google, Facebook, YouTube, Twitter, LinkedIn, Instagram and Microsoft.

How many websites passed WCAG 2 accessibility standards?

The WCAG 2 failure rate based on automatically detectable errors was 98.0% in August compared to 97.8% in February. While the number of detectable errors decreased marginally, the number of home pages with WCAG failures increased slightly over 6 months.

Which are the most common website accessibility issues?

Bar chart showing most common WCAG failures.

WCAG Failure Type % of home pages in February % of home pages in August
Low contrast text 85.3% 86.1%
Missing alternative text for images 68.0% 67.9%
Empty links 58.1% 58.9%
Missing form input labels 52.8% 53.2%
Missing document language 33.1% 30.5%


Which issues do most websites fail on?

1. Low contrast text

Having the appropriate contrast ratio between the text and background colours makes words easier to read. For people with moderate to low vision and colour deficiencies, having adequate contrast is the difference between being able to read or not.

WCAG guidelines state that there must be a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. Graphics and user interface components, like buttons, should also have a contrast ratio of at least 3:1.

Screenshot from WebAIM's Colour Contrast Checker website with example text in yellow and purple showing a pass.
WebAIM’s Colour Contrast Checker tool

Use WebAIM’s Contrast Checker to check that your colours are WCAG compliant

2. Missing alternative text for images

For anyone who relies on a screen reader to process their images for them, this is essential. All images should have a descriptive attribute attached to them, known as alt-text.

Providing alternative descriptions is necessary for people using screenreaders and other assistive technology to understand your images.

If an image is decorative and provides no other purpose or meaning, using a null (empty) text alternative (alt=””) will convey this information to assistive technologies.

“Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.”

1.1, WCAG 2.0 Guidelines

Read W3’s web accessibility tutorial on images and text alternatives here

3. Empty links

If a link contains no text, the function or purpose of the link will not be presented to the end user. For keyboard and screen reader users, this can be confusing.

Either remove the link or provide text that explains where the link is going or what the end user will achieve by clicking it.

Read WCAG’s guidelines on link text for more information

4. Missing form input labels

All form controls, such as checkboxes, text fields and drop-down menus should have labels that describe what is being asked of the user. The purpose of the form control should be indicated in the html.

Web developers should use the label element within html to associate text with explicit form elements. The for attribute of the label should match the id of the form control.

See how to implement correct form input labels using this W3 tutorial

5. Missing document language

In HTML, the lang attribute identifies the language in which the text content is written on a page. It’s used by search engines to provide language-appropriate results and by assistive technology to switch language profiles and provide the correct pronunciation.

Learn how to add language attributes to html tags with this W3 tutorial

For web accessibility, what else has changed in the last six months?

  • Homepage errors decreased by 1%. The tool found an average of 59.1 errors per homepage in August, a slight decrease from 59.7 errors per homepage in February.
  • Home page complexity increased by 4.3% in 6 months. This changed from 783 elements per page in February, to 816 elements per page in August.
  • The number of websites who failed most WCAG 2 standards went up by 0.2%. In August, 98.0% of websites failed based on automatically detectable errors, compared to 97.8% in February.
  • The prevalence of alternative text on images improved, with 2.2% less alt-text errors found than in February.
  • The most notable change over this 6-month period is the significant increase in ARIA usage. Pages that include ARIA markup increased from 60.1% in February to 64.5% in August.

“While it is tempting to extrapolate these findings into an increase or decrease in web accessibility more broadly, using these and future data to draw trend lines over time will be more accurate.”


As WebAIM suggests itself, the six-month period between analyses is too short a time to predict long term accessibility trends. Yet it does remind us that even the top million websites, with their huge associated budgets, could be doing more to serve their disabled customers online.

Are you a web developer or agency who knows a lot about accessibility? Why not contribute an article? Get in touch with your suggestions today at [email protected].

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