Use automated tools to review accessibility

On this page:

Overview
Recommended tools
Types of content issues that automated tools can find
Get help

Overview

Important:

This information is intended for web developers, providing a holistic process for performing an initial pass of evaluating your website for accessibility. This is not a substitute for performing a complete Web Content Accessibility Guidelines (WCAG) 2.0 AA site evaluation, but following this full process will capture most of the WCAG 2.0 AA Guidelines more efficiently.

It is impossible to meet the website accessibility standards in IU's Americans with Disabilities Act Policy (UA-02) using only automated tools.

Automated tools can be useful for identifying certain types of web accessibility issues. There are many tools you can use, each with different strengths and weaknesses. Be aware that automated tools can find only about 30% of accessibility problems; the rest must be located using manual methods.

Automated tools can detect programmatic accessibility issues based on the code. For this reason, the tools will produce more accurate results if the code is valid. If you have not already validated your code, running the HTML Nu checker before using automated accessibility tools will improve the quality of the results.

There are many automated tools available for use.

Recommended tools

aXe

aXe is an accessibility rules library from Deque that is also available as a browser extension in Chrome or Firefox. The aXe library will only flag as errors the things that can be reliably programmatically checked. aXe strives to report zero false positives. The aXe extension is run on each web page individually, and exists in the browser's Developer tools.

aXe is a very useful tool for developers.

Accessibility Insights for Web

Accessibility Insights for Web from Microsoft is available as a browser extension in Chrome or Microsoft Edge. Powered by Deque Systems' aXe library, Accessibility Insights for Web offers a quick FastPass check to get you started and a full Assessment that includes step-by-step instructions for manually performing tests. Accessibility Insights for Web is run on each web page individually.

A Windows application version, Accessibility Insights for Windows, is available to test Windows applications.

Accessibility Insights is useful for developers.

WAVE

WAVE, from WebAIM, is available as either a browser extension or as a web service, which requires web pages to be public, rather than behind authentication. WAVE will flag errors which can be programmatically checked, and will also flag issues for further manual review. WAVE is run on each web page individually.

WAVE assesses the whole page after it has been rendered in the browser, which means that it will look at objects that are visually on the screen and objects that are hidden.

WAVE is a good tool for checking color contrast and headings automatically. Because WAVE checks the hidden content, some headings that are normally hidden may be shown.

WAVE is easy for anyone to use.

For tips on using this tool, see WAVE Help.

ARC Toolkit

ARC Toolkit, available as a browser extension in Chrome, will flag errors that can be programmatically checked, and will also flag potential errors for further manual review. ARC Toolkit is run on each web page individually and is accessed in the Chrome Developer tools.

Add ARC Toolkit in Chrome

ARC Toolkit is useful for developers.

ARC Toolkit also includes easy tests for focus order and new WCAG 2.1 success criteria Reflow and Text spacing as well as buttons to validate the code through the W3C Nu HTML validator.

AInspector

AInspector is a Firefox browser extension developed by the University of Illinois Division of Disability Resources & Educational Services. AInspector is run on each web page individually.

Add AInspector in Firefox

AInspector is most useful for developers. It will go deeper into explaining the issues and label a lot more manual checks than any other tool.

Helpful user guides are available in the AInspector Sidebar documentation.

FAE

FAE (Functional Accessibility Evaluator) is the web service version of AInspector. It will evaluate a site or section of a site, rather than each page individually.

FAE can be used on public-facing sites that can be "crawled". It works best with less dynamic, not personalized, content.

Faculty and staff of Big Ten institutions can sign into FAE with their school login credentials. The free institutional subscription is limited to 10 archived reports, 5 permanent archived reports, 50 web pages per report, and spidering depth of 3 layers.

FAE is most useful for developers. Use this tool for an overall examination of a public site. FAE helps in indexing the site, including identifying the title of each page.

For a thorough introduction to using these tools, see the one-hour Web Workshop video on using FAE and AInspector.

SortSite

SortSite is a testing tool from PowerMapper that is available to IU faculty and staff through IUanyWare. It will evaluate a site or section of a site, rather than each page individually.

Sortsite can be used on public-facing sites that can be "crawled". It works best with less dynamic, not personalized, content. Sortsite is helpful for seeing site-wide trends.

Sortsite is most useful for webmasters and developers.

The 10-minute tutorial, SortSite: The Basics (YouTube video) will help you get started.

Bookmarklets

Many bookmarklets are available that will highlight roles, states, and properties of various elements on a web page. Bookmarklets are JavaScript programs stored as bookmarks in your browser. They are easy to use: single click the bookmark and the JavaScript program will run on the current page.

To install a bookmarklet, open one of the bookmarklet resource links below. Choose the bookmarklet you want to install. Drag and drop the bookmarklet to your bookmarks bar.

In some browsers, you may need to manually add the bookmarklet. Copy the link address of the bookmarklet. Open the bookmark manager in your browser. Add a new bookmark. Enter a name for the bookmark and paste the link address as the URL.

The Javascript Bookmarklets for Accessibility Testing from Paul J. Adam are easy to use and highlight many important features of a web page.

Disability Resources and Educational Services (DRES) at the University of Illinois at Urbana-Champaign and Pixo have also created easy to use, open source accessibility bookmarklets.

A11y audit bookmarklets includes several useful tools, such as Are Ya Hidden? and List images.

Bookmarklets are useful for developers and designers.

Types of content issues that automated tools can find

Headings

Tools usually identify the programmatic heading structure of a web page. Some tools, such as WAVE, will present the headings as an outline of the page. Tools will catch:

Skipped heading levels
Missing h1 headings
Headings of the same level with the same text
Headings with no text content

Compare the HTML headings to the visual headings:

Visual headings should match HTML headings.
- Things that appear to be headings should be HTML headings.
- Things that are HTML headings should appear to be headings.
Headings should follow a hierarchical order, creating an outline for the page.
Headings should not skip heading levels.
The headings should describe the topic of the section.

Images

Tools will identify:

Images missing alt attributes
Images where the alt text is similar to nearby text
Instances where multiple images have the same alt text

A manual check is still necessary to verify that the alt text for each image is appropriate. For a more in-depth discussion of alternative text, see Alternative text for images.

Tables

Automated tools will find the most common table issues:

Data tables need accessible names. An accessible name may not be visible onscreen but is used by assistive technology to identify the table.
Data tables should have header rows and/or columns.
Layout tables should have the ARIA attribute role="presentation".
Tables should not have empty rows, columns, or cells.

Landmarks

Tools are useful for identifying landmarks and checking that the landmarks follow landmark rules:

All content should be contained in a landmark, including skip-links.
Every web page should have at least main and navigation landmarks.
Each page should have only one main, banner, and contentinfo landmark.
banner, main, contentinfo, and complementary landmarks must be top-level, not nested in other landmarks.
Landmarks of the same type, such as two navigation landmarks, must have unique names so they may be easily differentiated from each other.

ARIA

Automated tools will help identify common problems with Accessible Rich Internet Applications (ARIA). Many tools will identify:

Incorrect ARIA roles
Incorrect ARIA labeling
Invalid ARIA properties
Invalid ARIA attributes
Invalid ARIA values

Forms

Automated tools excel at checking certain aspects of forms. They will identify if:

Form elements are correctly labeled
Form labels are unique
Radio buttons are grouped in fieldsets
Fieldsets have legends
ID attributes are unique

Beyond the programmatic checks that automated tools carry out, forms will always require additional manual checking with keyboard and screen readers, and to explore their error handling.

Page language

Automated tools will check if the human language used on the page (for example, English) has been set using the lang attribute on the <html> element. Automated tools are not good at finding language changes within a page. If the language used on the page changes, you will need to manually check that the lang attribute has been used correctly.

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Get help

For questions or consultations, email the Enterprise Experience accessibility team.