Annotation has alt text
PAC fails “Annotation has alt text” when a comment, stamp, highlight or attachment has no description. Here’s what it means and how to fix it.
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This message comes from PAC (PDF Accessibility Checker).
Annotation has alt text is a PDF/UA check in PAC, the free PDF Accessibility Checker. It fails when an annotation, such as a comment, highlight, stamp, drawing markup or file attachment, has no text description. In PDF terms, the annotation has no Contents entry (the text that says what it is), and its tag, its place in the document's hidden structure, has no alternate text either. So assistive technology can't tell anyone what the annotation is for.
What this means
Annotations sit on top of the page rather than inside it. Links, comments, highlights, stamps, arrows and boxes, file attachments and form fields are all annotations. PDF/UA, the ISO standard for accessible PDFs, requires each one to be described in a way assistive technology can read:
- Comments and markups use the annotation's Contents entry. For a sticky note, that's the text you type in its pop-up note.
- Form fields use a tooltip instead, which is covered by the form field checks.
- Links have their own description and tagging rules, covered in Link annotations in Link tag.
PAC shows this check among its alternative text results, which is why people often search for it as "PDF/UA alternative text". The annotations that fail it most often are:
- Highlights, underlines and strike-throughs where nobody typed a comment.
- Stamps, such as "Approved", "Draft" or "Superseded".
- Arrows, boxes, lines and other drawing markups.
- File attachment icons with no description.
- Review comments left in a file that was meant to be final.
Why it matters
A screen reader user hears that something is there, such as "stamp" or "annotation", but not what it says or why it matters. If a stamp says "Superseded", or an arrow points at the fee that changed, a sighted reader gets the point at a glance and a screen reader user doesn't. That's a gap under WCAG 2.1 success criteria 1.1.1 Non-text Content and 4.1.2 Name, Role, Value.
Flattening doesn't make the problem go away
Flattening comments turns them into ordinary page content, so they no longer need a description as annotations. But like any other content, they then need a tag or an artifact mark (the label for decoration that screen readers skip). Otherwise PAC will report Content is tagged or artifacted instead.
How to fix it in Acrobat Pro and re-check in PAC
- Decide whether each annotation belongs in the published file. Open the comments list in Acrobat's Comment tool and delete anything that was only meant for reviewers. This is often most of them.
- For each annotation you keep, open its pop-up note and type a short description, such as "Approved stamp, signed by the planning director" or "Arrow pointing to the new permit fee". That text becomes the annotation's Contents.
- For a file attachment icon, add a description of the attached file in the same way, for example "Attached spreadsheet: 2027 fee schedule".
- Make sure each annotation is also in the tag tree. In the Tags panel's options menu, turn on Tag Annotations. Then choose Find, look for Unmarked Annotations, and use Tag Element to tag each one as
Annot, next to the content it refers to. - Save the file and open it in PAC. Confirm that this check passes and that no annotation-related failures remain.
If Acrobat's own checker also reports Tagged annotations – Failed, step 4 fixes that at the same time.
Fix it in the source file
Most unwanted annotations arrive with the export or are added during review:
- Word: before exporting, accept or reject tracked changes and delete comments you don't want readers to see. In the PDF options, set Publish what to Document, not Document showing markup. Microsoft documents that recent versions of Word can carry comments into the PDF as annotations, so exporting with markup showing is a common source of this error.
- Review workflows: add sign-off stamps and reviewer notes to a review copy, not to the version you publish.
- Attachments you need: if a PDF must include an attached file, describe it at the time you attach it.
Fix it automatically with Includoc
Includoc adds a description to each annotation automatically and tags it in reading order, so both this check and Acrobat's tagged annotations rule pass. Printer marks, which have no meaning for readers, are marked as artifacts instead.
What we don't decide for you is whether a reviewer's note should be published at all. We describe what's in the file. If it still contains comments that weren't meant for readers, delete them before you upload.
Upload your PDF to fix this automatically
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Standards
| Standard or tool | Reference |
|---|---|
| WCAG 2.1 | |
| PDF/UA-1 (ISO 14289-1) | Clause 7.18.1 |
| Matterhorn Protocol | Checkpoint 28-002 |
| PAC wording | Annotation has alt text |
Related errors
- Tagged annotations – Failed: Acrobat's check for annotations that are missing from the tag tree.
- Link annotations in Link tag: how links are tagged and described under PDF/UA.
To understand how PAC's checks map to the standard, read PDF/UA explained, or check a PDF free to list every annotation that needs a description.
Related
- Tagged annotations – Failed
Acrobat’s “Tagged annotations – Failed” means links, comments or stamps aren’t in the tag tree. Step-by-step fixes in Acrobat Pro and at the source.
- Link annotations in Link tag
PAC fails “Link annotations in Link tag” when a link’s clickable area isn’t inside a Link tag. Learn how PDF links are built and how to fix them.
- PDF/UA explained: PDF/UA-1, PDF/UA-2 and the Matterhorn Protocol
PDF/UA is the ISO standard for accessible PDF files. What PDF/UA-1 and PDF/UA-2 require, how Matterhorn and validators test them, and the identifier.