Microsoft's PDF Export Beats Adobe on Alt Text, 400-Check Test Finds

Microsoft's built-in PDF export preserves alternative text for nearly every image type tested, while Adobe's Acrobat tab loses or corrupts it across most formats, according to a WebAIM review of more than 100 test cases.

WebAIM ran every case first in desktop Word and PowerPoint 365, then generated three PDF outputs from each file. The paths: Adobe's Acrobat PDFMaker (version 25.1.20) on Windows, Adobe's Create PDF cloud service on October 29, 2025, and Microsoft's Save as PDF feature. The total reached more than 400 separate checks across both applications.

What did WebAIM test?

The test set covered every image category the team could identify in Word and PowerPoint 365: photos, shapes, icons, SmartArt, charts, 3D models, tables, groups, text boxes, WordArt, the Draw tab, emoji, video and audio placeholders, and text with effects such as shadows. Microsoft 365 build 2509 supplied the source documents on Windows; the cloud-service PDFs were created on October 29, 2025.

The headline finding: alt text entered in Word and PowerPoint travels intact through Microsoft's own PDF exporter. Adobe's Acrobat tab does not. Within Adobe, only Pictures, the images that trigger the "Picture Format" ribbon, survive conversion cleanly on both platforms.

Where does Microsoft's exporter win?

WebAIM's review, building on improvements Microsoft announced in late 2024, credits the built-in exporter with the broadest alt text coverage. Every image type except emoji retained its alternative text in the resulting PDF. The main criticism is repetition. Microsoft appends the image type to the alt text, so a two-way arrow labelled "Two-way communication" emerges as "Two-way communication (Arrow: Left-Right)", drawn from roughly 150 shape types in the catalogue.

Charts behave better than under Adobe. PDFMaker offers no alt text support for charts in Word or PowerPoint, and the underlying chart text never enters the alt text automatically. Authors must add it by hand or supply a nearby table.

Where does Adobe's Acrobat tab fall short?

Almost everywhere. PDFMaker drops alt text for shapes, ignores Draw tab output in PowerPoint entirely, and loses content from Text Boxes and WordArt in Word. SmartArt's nested alt text is never carried into the PDF. Tables given alt text in PowerPoint can have their contents ignored altogether. WebAIM's summary: PDFs from the Acrobat tab have problems with basically every type of image except Pictures.

What does this change for document authors?

Teams producing accessible PDFs from Office should prefer File → Save As PDF over the Acrobat tab whenever content is non-trivial. For documents already flowing through Adobe, WebAIM recommends converting complex images to Pictures first, by right-clicking on Windows and selecting Paste as Picture, or using Paste Special with one of the four Picture file types on Mac. The trade-off is real: pasted-as-Picture images cannot be edited, and pasting itself wipes the source alt text. Authors must copy, paste as a Picture, then re-enter the alternative text before deleting the original.

Which exceptions remain?

• Emoji. Only Adobe's Create PDF cloud service supplies alt text, and it does so by rendering black-and-white emoji.
• Draw tab drawings. Group them, convert to a Picture, or accept that PowerPoint output via PDFMaker will not contain them.
• Text effects in Word. Shadows and reflections cause text to be ignored under the Acrobat tab and produce anomalies such as screen readers announcing "dot" for each period.
• Decorative markup. The Adobe cloud service ignores "Mark as decorative" unless the container carries an outline or fill.

WebAIM's verdict for the everyday author: pair the Accessibility Assistant with the Alt Text pane, enable inline prompts under File → Options → Accessibility, and choose Microsoft's PDF exporter unless a workflow forces the Acrobat tab. As Microsoft continues to close the gap it opened in late 2024, the question for accessibility teams is whether Adobe will respond with equivalent changes to PDFMaker before document reviews begin to flag the discrepancy by name.