Accessible Excel (implementation guide)

Content-bearing illustrations, diagrams and groupings have a short, concise alternative text. The alternative text of diagrams refers to their table via their table name, contains the diagram type and information on the content. Illustrations and groupings with no meaning are marked as decorative.

What is meant by this?

To improve the approval of an Excel file, all illustrations, diagrams and groupings of graphical elements contained therein should be provided with alternative texts that describe them. An alternative text is a short and concise description of the content of the graphic that is read by screen readers and speech output devices in order to understand the content.

Purely decorative illustrations, diagrams and graphic groupings with no relevance to the content should be labelled accordingly. In Excel, these elements can be marked as "decorative" to signalise that they do not contain any relevant content and can therefore be skipped by screen readers.

Charts are generated in Excel from data tables. The alternative text should contain the table name in order to establish the connection between the chart and the table. The alternative text should also contain the chart type and the content of the chart.

Why is it important?

A suitable alternative text for an image is important as it enables all recipients to understand the content of an image. If an image has no alternative text or the alternative text is insufficient, the image becomes invisible to screen reader and speech output users. This means that these recipients miss out on important information that could be contained in the image.

An appropriate alternative text describes, for example, an illustration briefly and concisely and conveys how it relates to the content of the file or table. If the illustration contains important information that is not or cannot be presented differently in the text, it is important to include this information in the alternative text so that it can be recognised by screen readers and speech output. A detailed description of the illustration is not usually necessary for an alternative text. In the event that an illustration, diagram or graphic grouping contains a lot of important information, this should be included in the text itself or a detailed text alternative should be provided. As a general rule, an alternative text should contain a maximum of 120 characters.

The alternative text for an Excel chart of sales development could read: "Sales development by quarter - bar chart. Table 'Annual turnover' 2021-2023." This clearly communicates what the chart shows, what type it is and which table it refers to. Users who use screen readers can thus grasp the relevant information on the company's sales development even without visually grasping the chart.

How can I implement/check it?

To add an alternative text for an image in Excel, left-click on the image and select "Alternative text" from the "Image format" menu. Then enter a precise description of the content of the image in the text field. If the image is only decorative, mark it as such and leave the alternative text field empty. To mark an image as decorative, proceed as follows:

1. Select the image you want to mark as decorative.
2. Right-click on the image and select "Format Image" from the drop-down menu if you have a Windows computer. Alternatively, if you have a Mac, you can select "Display Alt Text" and a window/menu will open on the right-hand side
3. Select the "Alt text" item in the "Image format" tab.
4. In the Alt Text dialogue box on a Windows computer, select the "This image is decorative" checkbox, while on a Mac you can select the "Mark as decorative" option below the text field.
5. Click on "OK" to save the changes.

Excel offers an integrated function that allows you to check whether or not an alternative text exists for a graphic. You can also check for redundant alternative texts by reading the text around the graphic and ensuring that it does not match the alternative text.

To use the integrated function in Excel that allows you to check whether alternative text is available for illustrations, diagrams or graphic groupings, proceed as follows:

1. Select the image for which you want to check the alternative text.
2. Right-click on the image and select "Format Image" from the drop-down menu. With a Mac, you can alternatively select "Display Alt Text" and a window/menu will open on the right-hand side
3. Select the "Alt text" item in the "Image format" tab.
4. Check whether the text field for the alternative text is filled in. If so, the image contains an alternative text. If not, the alternative text is missing and should be added.

Excel automatically generates its own ALT texts on request, but in many cases these do not fit and should therefore be checked and adapted if necessary.