A PRACTICAL GUIDE + A SIMPLE EDITOR
Review and bulk-edit image descriptions for more accessible slides.
See picture descriptions across an ordinary .pptx in one place. Edit individual images or a selected group, then download a new copy.
Opens a separate, ad-free editor in a new tab. Choose your file there; the editor processes it in your browser.
01 / WRITE FOR THE CONTEXT
These examples use an original synthetic photo and invented chart data. They contain no course material or research findings.
Slide purpose: notice which way the stem leans.
The revision identifies the visible relationship. “Plant photo” names the subject without giving the observation the slide needs. Do not claim the photo proves a cause or a treatment effect.
Slide purpose: compare the germination counts and proportions.
Tray B has six more germinated seeds: a difference of 30 percentage points. The description preserves the values and time window; naming the bar colors alone would miss the comparison.
This two-bar chart is simple enough to describe in a sentence. For a dense chart, give the takeaway and make the essential values available in an accessible table or longer description alongside it. Do not promise a table that your slide does not contain.
The general approach follows W3C’s guidance for complex images. The examples and dataset here are original.
| Tray | Germinated | Proportion |
|---|---|---|
| A | 12 of 20 | 60% |
| B | 18 of 20 | 90% |
For more on choosing an alternative based on purpose and context, see W3C’s image decision tree. Its HTML instructions are not PowerPoint controls.
02 / TRY THE WHOLE WORKFLOW
Download this synthetic deck and open it in the editor. No account or payment is needed. The download does not automatically open or send a file to the editor.
About 1.7 MB each. The completed file is a comparison copy, not an automatic evaluation of your work.
| Slide | Title | Starting state | What to do |
|---|---|---|---|
| 1 | Observe the direction of growth | “Plant photo” | Describe the lean toward the window. |
| 2 | Set up an observation station | Missing description | Select with slide 4 for bulk apply. |
| 3 | Compare two trays after 7 days | “Chart” · picture of a chart | Add the values and time window. |
| 4 | Observation station reminder | Missing · picture inside a group | Use the same setup description as slide 2. |
| 5 | Pause for a question | Marked decorative · read-only | Review in PowerPoint; leave it unchanged here. |
| 6 | Native chart: work in PowerPoint | Native chart · outside picture list | Review the chart in PowerPoint. |
In the editor, open alt-text-practice.pptx. Expect 6 slides, 5 images, 2 missing descriptions, 0 edited. Slide numbers follow presentation order. Thumbnails show embedded images, not rendered slides.
Turn on Missing descriptions only. Check the boxes for slides 2 and 4. Confirm 2 selected. Selections persist across filters and pages; clear them before starting a different batch.
Enter the setup description below and choose Apply to 2 images. The two missing rows disappear from the filtered view. Turn the filter off to inspect them.
A terracotta pot holding one seedling sits on a wooden sill beside a window.
Choose Undo. Both descriptions return to empty and the edited count returns to zero. Reapply the setup text to the two selected pictures when ready.
Click the slide 1 picture row to leave bulk selection, then apply the direction-of-growth description from the photo example. Do the same for the chart image on slide 3. Expect 4 edited; slide 5 remains decorative.
Apply or discard any typed draft, then choose Download new copy. The editor adds -descriptions to the filename. Your source file stays unchanged. Compare your descriptions with the completed example and follow the review checks below.
03 / RECOGNIZE WHAT NEEDS REVIEW
An informative picture with no description is unfinished. A decorative picture adds no information needed to understand the slide. That decision depends on the slide’s purpose.
In this exercise, slide 5 is only a pause for a question, and the repeated plant photo is explicitly marked decorative. In the editor, it is read-only and is not counted as missing.
04 / CHECK THE FIT
The editor changes picture descriptions. It does not audit every part of a presentation or establish accessibility compliance.
Use an unencrypted PowerPoint Presentation (.pptx). Legacy .ppt, macro-enabled .pptm, templates, encrypted or digitally signed packages, Strict Open XML, and ZIP64 are not accepted.
For a rejected file, work from a separate supported copy saved in PowerPoint if appropriate. Renaming its extension is not conversion.
Pictures on slides, including those in ordinary groups, are listed. Each occurrence can have its own description even when several occurrences share one embedded image.
Existing separate image titles and decorative flags are preserved. The editor does not overwrite the original file.
Native charts, SmartArt, shapes, text boxes, connectors, image fills, backgrounds, masters, layouts, notes, and alternate-content branches are outside scope.
A picture of a chart can be edited; a native PowerPoint chart cannot. Review the scope notes and the actual slides.
PNG and JPEG images can have previews. Formats such as SVG, EMF, WMF, and GIF receive a labeled fallback. Linked external targets are not fetched; linked, missing, and audio/video poster pictures are read-only.
The thumbnail is the embedded image. It does not reproduce slide cropping, rotation, layering, animation, or surrounding text.
05 / FINISH IN POWERPOINT
Testing with synthetic files is evidence for those cases, not a guarantee for every deck. A successful download or a cleared missing-description count does not mean the presentation is fully accessible.
06 / WHY NOW
The Department of Justice’s web accessibility rule for state and local governments, including public colleges and universities, now has compliance dates of April 26, 2027 and April 26, 2028, depending on the population of the government the institution belongs to. Read the sourced summary and the PowerPoint alt-text steps. It is not legal advice.