I received several requests to make my German-language article on accessible PDFs from LibreOffice available in English as well. Here is the translation, which includes the updated features implemented in recent months.

I have been using the free office software LibreOffice, and especially LibreOffice Writer, for years in my professional life. Its range of features is more than sufficient for my purposes. Unlike with MS Office, I don't have to deal with changes in subscription terms and similar uncertainties. Another advantage is that LibreOffice can create accessible PDFs natively. My step-by-step guide shows you how to do this.

Accessibility in LibreOffice

For several versions now, LibreOffice has not only supported PDF/A (Archive PDF) export, but can also output accessible PDF files. More specifically, these are PDF/UA files (UA stands for Universal Accessibility).

This article shows how to do this using LibreOffice 25.8.

Accessible texts with images – basic considerations

There are a few things to keep in mind in all office and layout programs if you want to achieve an accessible result:

1. The file needs a document title.
2. The correct language must be set.
3. A structure is created by assigning styles. This applies to paragraphs (e.g., headings, body text, and lists).
   • Empty paragraphs and indentations using spaces or tabs should be avoided.
   • Text markup (bold, italics, or color) should only be implemented using character styles.
4. All images and graphics are given descriptions using alternative text/AltText.
5. Tables are created using styles for table content and table headings.
6. A table of contents must be created using standard tools. Manually created TOCs won’t work. This also applies to other directories or references.
7. Contrast: The text must stand out sufficiently from the background.

Step by step to a valid PDF/UA

To make sure that the creation of an accessible PDF/UA document is successful, it is vital to observe the above points, some of which can be checked directly in LibreOffice. However, it is strongly recommended that the PDF be tested afterwards.

1. Assign a document title in the properties

A common obstacle to creating a standard PDF/UA file is a missing or incorrect document title. To enter this, open the input window via File/Properties. Under Description, you will find the field for the Title, which must be filled in. (For information on what you need to bear in mind when exporting PDFs to ensure that the document title is actually transferred, see the section on PDF export.)

2. Define language

To ensure that assistive software can read texts correctly, it needs an identifier for the language used. English texts read aloud with a German voice sound strange, to name just one example. A PDF without language identification fails the test.

New documents in LibreOffice use the language selected in the Preferences under Language and Locales/General.

If it is necessary to select a different language for a document, this can be done via Tools/Language.

3. Use styles for paragraphs and characters

Styles for paragraphs and characters not only ensure that a text looks “nice.” Styles also reflect the text structure. A logical sequence of headings helps with reading (or listening), and the structure of the text provides a better overview.

Headings are also used for navigation on text pages, for example. This allows you to jump from Heading 1 to the next Heading 1 to quickly find a specific paragraph, even if you have a visual impairment.

Lists should be created as real lists (and not with indents and hyphens). This ensures a logical structure. A screen reader “understands” correctly structured lists.

In general, design tricks such as multiple line breaks should be avoided, as these create empty paragraphs.

The marking of text using the B and I symbols in the upper control bar is also not clear enough. Two character styles are available for correct use: Emphasize (italics) and Strong Emphasize (bold).

Another important character style is the Internet Link.

4. Alternative text for images, graphics, and hyperlinks

Descriptions are used for accessibility so that visually impaired people can also find out what can be seen in images and graphics. Screen readers read aloud these descriptions, which are called alternative text (AltText).

LibreOffice provides features for storing these descriptions.

Right-clicking on an image or graphic opens a selection. Continue here via Properties… (Image) and finally to the Options tab to get to the appropriate window.

Under the Options tab, the field for Text Alternative is crucial. This text should be precise but not too long. The rule “briefly explain to someone on the phone what you see” can be helpful here.

For purely decorative elements and graphics, there is a checkbox labeled Decorative.

LibreOffice provides a similar procedure for hyperlinks: Right-click on a link placed in the text to access the Edit Hyperlink… option.

However, it is not mandatory for PDF/UA to provide alternative text for hyperlinks. Therefore, you can ignore the corresponding warning in the program's own check or disable it program-wide.

5. Tables

First, a preliminary remark: Tables should only be used for actual tables and not misused for design purposes.

Tables consist of two components: the table content and the table header. The header can be the top row or the left column. Both markups can be found in the paragraph styles.

6. Table of contents (Index)

If tables of contents and other indexes are not created manually but using the built-in features of LibreOffice, they will also be included in an exported PDF/UA file, including their structure.

In most cases, the headings contained in the document are used for the table of contents. In the Table of Contents, Index or Bibliography window (found under Insert: Table of Contents, Index), you can set the level to which this applies. You can also include additional styles for the table of contents.

The structure of a table of contents in LibreOffice is transferred to a structured PDF during export.

7. Preliminary checks for accessibility in LibreOffice documents

For several versions now, the word processing program has offered an Accessibility Check. The corresponding window opens by clicking on the icon (with the figure in front of a document symbol) in the right-hand bar.

If, for example, alternative text for an image is missing, you can click on the Fix… button to enter the text later.

LibreOffice can also find text that does not contrast clearly enough with the background. In this case, the text contrast should be increased.

The properties that LibreOffice takes into account during the check can be viewed by clicking on Options… (top right). Here you can deactivate checks (such as alternative text for hyperlinks).

8. Exporting an accessible PDF (PDF/UA)

LibreOffice offers several settings for exporting PDF files (and also EPUB).

The Universal Accessibility (PDF/UA) option is available for export.

Clicking on the Export button starts the PDF creation process.

If the document contains errors, a warning will be displayed. The error repair process goes as shown above.

9. Checking the accessible PDF (PDF/UA)

Once the PDF/UA file has been created (or if you have received a PDF/UA file from an external source), you may want to check whether it complies with accessibility standards.

There are a number of online and desktop tools that can be used to check PDF files for accessibility features.

For example, the PDF Association is compiling a collection of PDF-related tools. This list can be narrowed down, for example, to PDF solutions for checking PDF/UA.

I would like to briefly introduce two solutions here.

PAC – PDF Accessibility Checker

PAC offers comprehensive options for checking PDF files for compliance with PDF/UA and WCAG specifications. PAC can jump directly to problem areas in the PDF. The comprehensive test report can help you find problem areas and fix the errors. The reports can also be exported and shared with partners.

However, the desktop program does not (September 2025) run on macOS or Linux. The developers currently are working on it. In the meantime, axesCheck can provide a workaround.

axesCheck from axes4

With axesCheck, PDF files can be uploaded via a browser, regardless of platform, in order to check them for compliance with PDF/UA and WCAG. The file size is limited to 10 MB.

Conclusion

A lot is currently being done to promote digital accessibility. Creating and checking PDF/UA files is now widely available—even with free solutions.

It may well be that the methods shown here will look slightly different in the near future. The PDF/UA specification itself will also continue to evolve.

The key point is that accessible files can be created with a manageable amount of effort. And accessible (= structured) content enables “better” documents overall.