Tableau Dashboard Accessibility Guide

At The Ohio State University, accessibility means ensuring that all individuals—including those experiencing barriers related to disability, language, cognition, or technology—can access information, engage with content, and benefit from services in an equally effective and timely manner. 

This guide is designed to support the creation and remediation of accessible Tableau dashboards, ensuring that visual data is usable and meaningful for all users. Accessibility considerations are critical for people with disabilities, as well as for those experiencing situational or temporary limitations. Designers should proactively account for a wide range of user needs, including:

• Screen reader compatibility for blind and low-vision users
• Keyboard navigation for users who cannot use a mouse
• Screen magnification and zoom functionality
• Clarity in language and layout for users with cognitive disabilities
• Color contrast and visual cues for users with color vision deficiencies

These needs can be met more effectively by applying the principles of universal design that is inherently accessible and usable by as many people as possible without the need for adaptation. As the National Disability Authority states, "This is not a special requirement for the benefit of only a minority. It is a fundamental condition of good design. If a product is accessible, usable, and a pleasure to use, everyone benefits."

Understanding WCAG and Legal Standards

The Web Content Accessibility Guidelines (WCAG) provide a framework for making digital content accessible. WCAG 2.0 Levels A and AA are the current standards referenced under Section 508 of the Rehabilitation Act and the Americans with Disabilities Act (ADA). These guidelines are structured around four core principles:

1. Perceivable – Users must be able to perceive the information being presented.
2. Operable – Users must be able to navigate and operate the interface.
3. Understandable – Users must be able to comprehend the information and how to use the interface.
4. Robust – Content must work reliably with a wide variety of assistive technologies.

This guide will focus on specific WCAG success criteria that are most relevant to Tableau dashboards. Some WCAG standards are not directly applicable due to the nature of Tableau's platform. Others, such as those from WCAG 2.1 or Level AAA, may be considered best practices even if not legally required.

About This Guide

This document includes:

• An overview of accessibility concepts applicable to Tableau
• Step-by-step guidance for implementing accessibility features
• Examples  
• Testing strategies, including involvement of users with disabilities and assistive technologies

By following this guide, Tableau dashboard developers at Ohio State can create more inclusive and effective data visualizations—ensuring access to critical information for all members of the university community.

Guidelines

1. Descriptive Links

Explanation: Whenever a link is included in a dashboard, it must be accompanied by descriptive text that clearly explains what the link is and where it will lead. This helps users make informed decisions before clicking and sets appropriate expectations about the content they will access.

Workbook and dashboard names should be short, purposeful, and consistent as these names directly influence the URL generated on Tableau Server. If creating multiple versions of a workbook, leverage the folder structure (Sandbox or Personal Space) and description field in Tableau Server. Similarly, sheet names should be brief, intentional, and consistent. These names appear in the download dialog. 

Process: Publishing Workbooks and URL Names

When publishing a workbook to Tableau Server, name the workbook appropriately. Leverage location and descriptions. 

Tableau provides additional information on publishing accessible views. 

Example:

Process: Links to Sites

When adding a link to a dashboard, add an Image. Enter the URL. Add Alt Text. 

Example:

Process: Dashboard Navigation

If including navigation inside a dashboard (for example with icons, arrows, or text), add ‘Navigation’ from Dashboard Objects. Double click to edit. Select where to navigate. Enter a descriptive title. Please note, if using an Image button style, you must use tool-tip text. 

Example:

2. Descriptive Title

Explanation: Every dashboard must include a title that describes the content of the page. Titles should also be included for all charts, graphs, or tables. This allows people use assistive technology to hear a preview of the content displayed in data visualizations. 

Process: Double click at the top of a sheet to add a descriptive title. This may also be accomplished by double clicking the sheet title tab. 

To add a title to the dashboard, drag a text object to the dashboard.

3. Text Requirements

3.1 Title and caption have narrative text

Explanation: Every graph or chart in Tableau must include a brief text description of the data it presents. This is essential for accessibility, as screen readers cannot interpret text embedded within visual elements like images or graphs. Labels or text placed directly inside the visualization will not be read aloud to users who rely on assistive technologies.

To ensure accessibility, use titles and captions, which screen readers can detect and read. When using captions, remove the default autogenerated text and replace it with meaningful, custom descriptions. Make sure that both titles and captions are enabled (via the “Show Title” or “Show Caption” options in the Worksheet menu), as screen readers recognize only those elements.

Note that Tableau applies heading tags (<h1>, <h2>, <h3>) to titles and extends this structure to captions, further supporting accessibility for users navigating with screen readers.

Process: 

1. Right click the arrow at the top of the graph or chart and select either “Title” or “Caption”. You will then see the title at the top or the caption at the bottom. 

2. Right click on the title or the caption and click “Edit Title” or “Edit Caption.” 

3. Add 1-3 sentences of descriptive text. 

4. Click “Apply” and then “OK.”

The title of the graph should be bolded and larger than the descriptive text. Per Ohio State brand guidelines:

• Dashboard and section headings should be in Georgia, and data values/chart elements should be in Arial.
• Use 80% dark gray (#212325) or black (#000000) for optimal readability and differentiation between text elements.
• Do not vary font weights, size or color within a dashboard unless the text is presented as a graphical element.
• Avoid using scarlet as the primary color for titles and worksheet text and tooltips.

Additional brand guidelines are available on brand.osu.edu.

3.2 Convert text objects to worksheets

Explanation: Text objects in Tableau are not read by screen readers. To ensure that the dashboard narrative is accessible, all text objects should be converted to worksheets OR captions must be visible. 

Process to convert text objects to worksheets

1. Check the dashboard for text objects. Complete steps below for each text object. 

2. Double click on the text object. 

3. Highlight the text and copy it.

4. Delete the text object. 

5. At the bottom of the screen, click left of the three + signs to create a new worksheet. 

6. Double click the name of the worksheet at the bottom and re-name it. 

7. In the new worksheet, double click on the title at the top and paste the text into the title. If there is too much text and the character limit is exceeded, use captions for the remaining text.

 8. If there are over 1000 marks on the page, the screen-reader will skip the title. In this case, you may need to add something to the body of the sheet, even if it is only a blank calculated field. 

9. Adjust the font, sizing, and background of the title as needed. 

10. Return to the dashboard. Select the worksheet from the left side of the screen. 

11. Then add the new worksheet to the dashboard. There are two methods for this: 

• Click and drag it over to the dashboard where you want the sheet to be. 

• Or right click and select “Add to Dashboard.” The sheet will then be added automatically to the top left corner of the page. 

12. Select the arrow in the top right and click “Show Title” and then “Show Caption” for the title and the caption to be read by the screen-reader. 

13. Move and resize the worksheet on the dashboard as needed. It is often helpful to put the new sheet into an existing container or create a new container to ensure a consistent layout.

Process to display captions

1. On a worksheet, go to Worksheet – Show Caption from the menu.
2. Double click in the caption box to edit.
3. Edit the caption.
4. Click ‘OK’.
5. On a dashboard, drag the sheet.
6. Double click on the sheet and select ‘Caption’. The edited caption will appear. 

4. Data Field Names

Explanation: Renaming data fields using aliasing in Tableau is a common practice to make labels more meaningful, especially when original field names are unclear. However, assistive technologies that access the underlying data tables cannot detect aliases—they read the original field names instead. To ensure clarity and accessibility for all users, it’s best to rename the field directly in the data source rather than relying on aliases alone. Additionally, it can reduce technical debt if fields are renamed directly in the source – ensuring your future self (or other future developers) can easily identify fields used in calculations. 

5. Descriptive heading with key takeaways

Explanation: Each dashboard should include a descriptive heading that communicates the key concepts or takeaways a user should understand at a glance. While the level of detail may vary depending on the content, it’s important to strike a balance—too much text can overwhelm or distract from the rest of the dashboard. This heading should be placed at the top of the dashboard and incorporated as part of the title to ensure it is both visible and accessible.

6. Dashboard uses plain language principles

Explanation: Writing in plain language is writing in a way your audience understands. When you use plain language, your audience can find, understand and use what they read.

1. Use common words that clearly and directly state what you mean.
2. Use short, simple sentences.
3. Share information in a logical order.
4. Avoid jargon or abbreviations.
5. Write like you talk. Use active voice and present tense whenever possible.

 7. Enable users to download summary data

Process: Work with your Primary Project Lead to customize the permissions for your project to grant users the ability to download summary data but not full data from the workbooks tab. 

Please visit Tableau’s website for additional information about permissions. 

8. Alt text for images

Explanation: All images used in a dashboard must include a text alternative that conveys the same meaning or purpose as the image itself. This is especially important when the image contains a link—descriptive text should clearly explain the destination or action associated with the image. Providing this context ensures that users relying on screen readers or select-to-speak technology understand where the image will take them and can navigate the dashboard effectively.

Process:

1. From a worksheet, click Worksheet in the toolbar. Click Accessibility.
2. Review and if necessary, edit the alt text.
3. Click ‘OK’.

9. Descriptions for filter, parameter, set, legend titles

Explanation: Any interactive content that requires user input must include clear labels or instructions to guide users. This is especially important for elements with a call to action, ensuring that all users understand what is expected and how to interact with the dashboard effectively.

Process: This process relates to filters but can be applied to parameters, sets, and legends. 

1. On a dashboard, Right click again and select ‘Edit Title’. A text box will appear. Edit the title.
2. Click ‘OK’.

10. Color paired with labeling or shapes

Explanation: Since some users may experience visual impairments or color vision deficiencies, color should not be the sole method for distinguishing between categories or areas within a dashboard. To ensure accessibility, use additional cues—such as text labels, patterns, or shapes—to convey differences and support all users in understanding the content.

11. Text contrast ratio of at least 4.5:1 or 3:1 if large (18pt or bolded 14pt)

Explanation: The color contrast between text and background must meet accessibility standards to ensure readability for users with low vision or visual impairments. Specifically, the contrast ratio should be at least 4.5:1 for regular text and 3:1 for large text (defined as 18-point or larger, or 14-point if bold). Adequate contrast helps ensure that text remains legible and distinguishable from the background for all sighted users.

Process: To ensure that text meets the standard ratio requirement, test the contrast ratios using a contrast ratio calculator such as this website. Tap the color code to insert the proper color code for the text (foreground) and background using the eyedrop icon. The page will then update to show the contrast ratio and indicate whether the two colors pass or fail the various standards. This ratio needs to be at least 4.5:1 for small text or 3:1 for large text. A 7:1 ratio is an optional reach goal (Level AAA). 

12. Repeated elements are consistent

Explanation: Maintaining consistency in dashboard design is essential for both usability and accessibility. This includes uniform use of fonts, colors, sizes, and functional components such as filters, navigation buttons, and charts—both within a single dashboard and across multiple dashboards. Design elements like color palettes, borders, and filter types should remain consistent whenever possible to help users quickly orient themselves without unnecessary confusion or distraction.

While consistency is a general best practice, it is especially important for users who rely on screen readers or screen magnifiers, as they depend on predictable layouts and page landmarks to navigate content effectively.

Process: It is recommended to build one dashboard and then duplicate for subsequent dashboards. An alternative is to use a template. 

13. Leverage Accessibility Coordinators

Explanation: Before going to production, ask your area’s accessibility coordinator to review. If the dashboard is not accessible and goes to production anyways, you will need to work with them to file an exception. 

Accessibility Testing for Tableau Dashboards

An essential step in ensuring a Tableau dashboard is accessible is testing it with both screen readers and select-to-speak technology. This testing should be performed on Tableau Server, as Tableau Desktop may behave differently and does not fully reflect the end-user experience.

When updating a dashboard, it is considered best practice to retest for accessibility, following the steps outlined below:

1. Visual Test
   1. Review the dashboard to identify whether any instructions or interactions rely on sensory characteristics—such as shape, size, visual position, or orientation—to convey information or guide users.
   2. Check whether color is being used as the sole method to convey information. In dashboard visualizations, ensure that color-coded data elements are also identified through other means, such as text labels, patterns, or shapes. Be sure to review elements like error messages to confirm that information is not communicated by color alone.
   3. Ensure headings are used and clear.
   4. Review alt text to ensure it makes sense.
2. Keyboard Navigation (Tabbing)
   1. The second part of accessibility testing involves checking whether all key elements of the dashboard can be accessed using only a keyboard (Tab, Shift+Tab, and Enter keys). Begin at the top-left corner and press Tab to navigate through each element. If certain components are skipped or inaccessible, adjustments may be needed to the focus order, element hierarchy, or by replacing non-accessible elements with accessible alternatives.
3. Screen Reader Testing
   1. Next, use a screen reader to verify that all dashboard elements are properly announced and understandable when read aloud. Several screen reader tools are available, but NVDA (NonVisual Desktop Access) is recommended due to its wide compatibility with Windows systems and its relative ease of use. NVDA provides a straightforward set of commands for basic navigation, making it a practical choice for accessibility testing.
      • Tip: Basic NVDA instructions and setup guidance should be reviewed before beginning this step to ensure accurate testing.

Common Mistakes

Avoid using scarlet. 

Download and set Tableau Desktop preferences to use Ohio State’s colorblind friendly, branded palette. 

Additional Best Practices

• Cognitive overload refers to the difficulty users experience when presented with too much information at once, making it harder to process and interpret the content. This is a widely recognized concept in data visualization and among Tableau developers. To reduce cognitive overload, dashboards should be kept simple, clean, and focused.
• Remove or avoid including any unnecessary numbers, lines, colors, or information that do not directly support the purpose of the visualization. Streamlining the content allows users to more easily grasp key insights and focus on the most important takeaways.
• Building on the importance of minimizing cognitive overload, it’s also essential to limit the amount of text included on a dashboard. Text should provide just enough information to meet accessibility standards and offer necessary context, without overwhelming the user or distracting from the visualizations. Striking this balance helps maintain focus on the data while ensuring the dashboard remains clear and usable for all audiences.
• Whenever possible, incorporate interactive elements such as filters, highlights, or actions into your dashboards to enhance the overall user experience. These features can vary based on the type of data being visualized but including at least one interactive component per dashboard can help keep users engaged, encourage exploration, and make the content more meaningful.