The WebAIM Million
The 2023 report on the accessibility of the top 1,000,000 home pages
For the fifth consecutive year, WebAIM conducted an accessibility evaluation of the home pages for the top 1,000,000 web sites. The evaluation was conducted using the WAVE stand-alone API (with additional tools to collect site technology and sector parameters). The results provide an overview of and insight into the current state of web accessibility for individuals with disabilities and trends over time.
Sites without home pages, pages that returned errors (404, etc.), pages with fewer than 10 HTML elements, and pages with more than 5,000 links to the same domain (for SEO purposes) were not included.
The WAVE accessibility engine was used to analyze the rendered DOM of all pages after scripting and styles are applied. WAVE detects end-user accessibility barriers and Web Content Accessibility Guidelines (WCAG) conformance failures. All automated tools, including WAVE, have limitations—not all conformance failures can be automatically detected. Absence of detected errors does not indicate that a site is accessible or compliant. Although this report describes only a subset of accessibility issues on only 1,000,000 home pages, this report provides a quantified and reliable representation of the current state of the inaccessibility of the most influential pages on the web.
Across the one million home pages, 49,991,225 distinct accessibility errors were detected—an average of 50.0 errors per page. The number of detected errors decreased slightly (1.6%) since the 2022 analysis which found 50.8 errors/page. "Errors" are WAVE-detected accessibility barriers having notable end user impact, and which have a very high likelihood of being WCAG 2 Level A/AA conformance failures.
Home Page Complexity
The home pages tested had over 1 billion page elements. Home page complexity increased significantly in 12 months, from an average of 955 elements in February 2022 to an average of 1050 elements per home page in February 2023 - a 10% increase.
The following chart shows the number of home page elements detected over the last five WebAIM Million studies:
Home page elements have increased over 34% in the last 4 years. It is promising that detected errors have decreased slightly while page complexity has increased notably, but it seems that accessibility progress could be greatly accelerated if the number of home page elements was not growing at such alarming rates.
4.8% of all home page elements had a detected accessibility error. Users with disabilities would expect to encounter errors on 1 in every 21 home page elements with which they engage. Page with more elements present an even higher proportion of errors per element than more simple pages.
Error density (number of errors divided by number of page elements) is provided in the site lookup, but is an unreliable metric of site accessibility. A significant number of page elements (
<span> elements, for example) may result in a lower error density (suggesting better accessibility), when in fact many new accessibility errors may have also been introduced. This report focuses on average number of detected errors—likely end user barriers—present as opposed to error densities (how diluted those errors are within page elements).
96.3% of home pages had detected WCAG 2 failures! This improved very slightly from 96.8% in 2022. Over the last 4 years, the pages with detectable WCAG failures has decreased by only 1.5% from 97.8%. These are only automatically detected errors that align with WCAG conformance failures with a high level of reliability. Because automatic testing cannot detect all possible WCAG failure types, this means that the actual WCAG 2 A/AA conformance level was certainly lower.
This chart shows the percentage of home pages with detected WCAG conformance failures over time:
While the rate of pages with no detectable errors was very low, 20.7% of pages had 5 or fewer detected errors and 30.8% had 10 or fewer. Most conformance failures fall into just a few categories, as described below.
|WCAG Failure Type||% of home pages in 2023||% of home pages in 2022||% of home pages in 2021||% of home pages in 2020||% of home pages in 2019|
|Low contrast text||83.6%||83.9%||86.4%||86.3%||85.3%|
|Missing alternative text for images||58.2%||55.4%||60.6%||66.0%||68.0%|
|Missing form input labels||45.9%||46.1%||54.4%||53.8%||52.8%|
|Missing document language||18.6%||22.3%||28.9%||28.0%||33.1%|
96.1% of all errors detected fall into these six categories. These most common errors have been the same for the last 5 years. Addressing just these few types of issues would significantly improve accessibility across the web.
Low Contrast Text
Low contrast text, below the WCAG 2 AA thresholds, was found on 83.6% of home pages. This was the most commonly-detected accessibility issue. On average, each home page had 30.4 distinct instances of low-contrast text, down slightly from 31.7 in 2022.
Images and Alternative Text
There were over 43 million images in the sample, or 43.4 images per home page on average. The number of images increased a surprising 9.1% over the last year—home pages are becoming increasingly graphical. 22.1% of all home page images (9.6 per page on average) had missing alternative text (not counting
alt=""). Over half of the images missing alternative text were linked images—resulting in links that were not descriptive.
10.9% of images with alternative text had questionable or repetitive alternative text—such as alt="image", "graphic", "blank", a file name, etc., or alternative text identical to adjacent text or alternative text.
These data show that one may expect over one third of the images on popular home pages to have missing, questionable, or repetitive alternative text.
The number of form inputs on home pages increased 13.8% in one year, from 4.4 million to 5.0 million. 35.8% of form inputs identified were not properly labeled (either via
title). This is a notable improvement from 39% in 2022, 49% in 2021, 56% in 2020, and 59% in 2019.
Over 24.7 million headings were detected (over 24 on average per home page). The number (and prevalence) of heading levels were:
- 1.7 million
- 7.9 million
- 8.7 million
- 4.0 million
- 1.7 million
- .9 million
The number of headings present on analyzed home pages increased 6.8% from 23.2 million in 2022 and increased 31% from 18.9 million in 2019. The prevalence of all heading levels also increased.
Because headings are the primary mechanism used by screen reader users to navigate content, their proper implementation is important. 20.1% of home pages had more than one
<h1>—an increase from 19.6% in 2022. There were 1,146,080 instances of skipped heading levels (e.g., jumping from
<h4>)— one in every 22 headings was improperly structured. Skipped heading levels were present on 42.2% of all pages (up from 40.4% in 2021 and 36.2% in 2019), and 7.9% of pages had no headings present at all (down from 9.9% in 2022).
80.9% of home pages had at least one region (or ARIA landmark) defined—continuing previous increases from 75.3% in 2022, 69.1% in 2021, 68.9% in 2020, and 62.4% in 2019. A
<main> element or main landmark was present on 41.5% of home pages, up from 36% in 2022, 30.1% in 2021, 27.8% in 2020 and 23.5% in 2019. 21% of home pages had a "search" landmark.
96% of home pages with a main region/landmark had only one instance (which is a correct implementation). Pages with a navigation region/landmark present averaged 2.4 of them per page.
77,437,071 ARIA attributes were detected—over 77 per page on average! ARIA code usage increased 29% in just one year and has nearly quadrupled since 2019.
Home pages averaged 15.2
aria-describedby attributes. The prevalence of ARIA labels increased 28% in just the last year.
80% of the one million home pages used ARIA (excluding ARIA landmark roles)—an increase from 74.6% in 2022, 68.1% in 2021, 64.6% in 2020, and 60.1% in 2019. Home pages with ARIA present averaged 68.6% more detected errors than those without ARIA—one would expect to encounter an additional 22 potential barriers on home pages with ARIA present.
Increased ARIA usage on pages was associated with higher detected errors. The more ARIA attributes that were present, the more detected accessibility errors could be expected. This does not necessarily mean that ARIA introduced these errors (these pages are more complex), but pages typically had more errors when ARIA was present.
5% of home pages had an ARIA menu (
role="menu"), but 31% of ARIA menus introduced accessibility barriers due to the lack of necessary ARIA menu markup and interactions.
Home pages also averaged 13.7
aria-hidden="true" attributes (up from 11.0 in 2022, 8.9 in 2021, and 6.6 in 2020) and 3.4
role="button" attributes (up from 2.5 in 2022, 2.2 in 2021, and 1.3 in 2020) per page. Home pages averaged 19.9 instances of
tabindex=-1 (up 95% from 2020).
17.2% of home pages had a "skip" link present, up from 13% in 2022. However, one out of every 6 "skip" links were broken—either they were hidden in a way that made them inaccessible or the link target was not present in the page.
89.8% of home pages had a valid HTML5 doctype—an increase from 86.1% in 2022 and 79.1% in 2021. Pages with a valid HTML5 doctype had significantly more page elements (average of 1095 vs. 651) than pages with other doctypes. 613 unique doctypes were encountered in the million-page sample.
We're grateful for the support of webshrinker.com in providing us the site category data. Their support makes this valuable information available.
The home pages were categorized based on content into IAB Content Taxonomy categories. The table below shows the number of home pages in each category (some sites may be in more than one category), average number of errors in that category, and the percent difference in errors for that category from the average of 50.0 errors for the entire million-page sample. In other words, the percentage difference is how much better or worse that category is than the average home page.
|Category||# of home pages||Avg. # of errors||% difference|
|Law, Government, and Politics||27,530||36.3||−27.4%|
|Technology and Computing||168,705||43.9||−12.3%|
|Health and Fitness||53,841||45.3||−9.4%|
|Food and Drink||31,305||45.8||−8.5%|
|Family and Parenting||6,006||48.1||−3.9%|
|Religion and Spirituality||11,314||50.0||0.1%|
|Home and Garden||26,655||52.3||4.5%|
|Arts and Entertainment||42,261||53.7||7.4%|
|Hobbies and Interests||84,634||58.2||16.5%|
|Style and Fashion||18,736||61.8||23.5%|
There were notable differences in accessibility errors for sites in different categories. Real estate and adult content home pages, for example, had over 2.5 times the number of errors on average as governmental web sites. Shopping sites, which were highly subject to accessibility complaints and lawsuits, were greatly improved from 90.5 errors to 72.1 errors on average over three years, yet this category remains among the least accessible.
807 unique top-level domains (e.g., com, .tv, .fashion, etc.) were represented in the million pages analyzed. Home pages with .com (491,056), .org (77,920), and .net (36,132) were the most common.
The table below shows the most common TLDs (n>4,000) with page counts, average number of errors, and percentage difference between from the average of 50.0 errors for the entire million-page sample.
|Top-level Domain||# of home pages||Avg. # of errors||% difference|
This shows notable differences between TLDs.
77% of pages specified a document language. Despite being a WCAG failure, pages without a language defined had fewer errors on average than most pages with a language defined.
This table shows the specified page language for the most common languages, number of pages in the sample, average number of errors, and percentage difference in errors from the overall average.
|Specified Language||# of home pages||Avg. # of errors||% difference|
|No language specified||178,475||47.3||−5.3%|
As with TLDs, there are significant differences in accessibility of pages in various languages. Latin-based languages generally fared much better than other languages.
Over 1,200 different types of web technologies were detected on the one million home pages. Common technologies detected on more than 5,000 home pages are listed below, ordered from "best" to "worst". Note that correspondence of additional errors with a technology cannot always be attributed to that technology.
Content Management Systems and Site Builders
|CMS||# of home pages||Avg. # of errors||% difference|
There was a wide diversity in the impact that the CMS choice appeared to have on accessibility with home pages.
|Framework||# of home pages||Avg. # of errors||% difference|
|Library||# of home pages||Avg. # of errors||% difference|
|Web Framework||# of home pages||Avg. # of errors||% difference|
Home pages in the sample that utilize the popular Bootstrap framework had 9.6 more accessibility errors on average than those that did not. We can't know from these data if Bootstrap introduced these errors, but there was a correspondence of increased errors when Bootstrap was present.
|Platform||# of home pages||Avg. # of errors||% difference|
|Ad Network||# of home pages||Avg. # of errors||% difference|
Pages that utilized any of these popular ad systems had more errors on average than those that did not. The data suggest that ads were among the strongest harbingers of accessibility errors. Home pages that utilize the common Google AdSense system had 17.7 more errors on average.
Other common technologies also correlated to more errors. 14.4% of pages had ReCAPTCHA (up significantly from 7.1% in 2022), and these pages had 6.6 more errors than average. 11.5% of pages were detected as having Progressive Web Apps (PWAs) and these pages had 5.2 more errors on average. 3.4% of pages had a Twitter feed with these pages averaging 13.3% more errors.
Here are some fun facts regarding this research:
- With 5 analyses of over one million pages each, the WebAIM Million database contains over four billion data points.
- 1,064,331 tables were observed (down from 1.3 million in 2022) on 162,727 pages. Only 178,332 (16.8%) of the tables had valid data table markup.
- The most errors detected on a single home page was 106,245!
Our 2023 analysis saw small decreases in the number of detected accessibility errors and WCAG conformance failures. Some sectors, such as government and education, fare better than others. While it is good to see progress, significant work remains to be done to make the web accessible to everyone. We at WebAIM hope that this report will help influence improved accessibility.