Do PDFs have "audio descriptions"?

Not as audio. The accessibility information a PDF carries is text, not sound: a screen reader generates the speech on the fly from the document's text alternatives — chiefly the alt text on images and the tagged content (headings, reading order, table structure, link and field labels). So a PDF's "audio description" of an image is really its alt text, which the screen reader voices. (Audio description as a distinct track is a video-accessibility concept; PDFs use text alternatives instead.) So "extract audio descriptions from a PDF" practically means extracting the alt text and accessibility text — the text a screen reader would speak — which is genuinely useful for auditing or reusing a document's accessibility.

Why would I want to extract a PDF's alt text?

A few real reasons: to audit accessibility (review whether images actually have meaningful alt text, not blank or "image1"), to reuse the descriptions (e.g. when converting the document to another format and wanting to carry the alt text over), to quality-check a remediation (confirm the alt text you added is present and correct), or to inventory what a screen-reader user would hear. Pulling the text alternatives out into a list lets you review them all at once rather than clicking each image. So extraction supports accessibility review and reuse — checking that the spoken experience of the document is actually good, and carrying that work forward.

How do I extract the alt text and accessibility content?

The alt text and structure live in the PDF's tag tree (the tagged-PDF structure that makes it accessible), so you read that structure to pull out the alt text per image and the tagged text in reading order. Accessibility/PDF tools that expose the tag tree let you see and export the alternative text and structure; you can compile the image alt texts into a list to review. If the PDF is not tagged at all, there is no alt text or structure to extract (it is not accessible in the first place) — which is itself a finding. So extraction works on tagged PDFs by reading their accessibility structure; an untagged PDF has nothing to extract, signalling it needs remediation.

What if the PDF has no tags or alt text?

Then there is nothing to extract, and that is the headline result: an untagged PDF (or images with no alt text) is not accessible, and a screen reader would skip the images or read nothing meaningful for them. So an extraction that comes back empty is telling you the document needs accessibility remediation — adding tags, reading order, and alt text — not that the tool failed. At that point the task shifts from extracting accessibility content to creating it: tag the document and write alt text. So treat an empty extraction as a diagnosis: the PDF lacks the accessibility layer and needs it added before it can serve screen-reader users.

How do I judge whether the extracted alt text is any good?

Review the extracted descriptions against what each image actually conveys: good alt text concisely describes the image's meaning/function in context, not "image" or a filename, and decorative images should be marked as such (empty alt) rather than described. So scan your extracted list for blanks where there should be descriptions, unhelpful placeholders, overly long or missing-the-point descriptions, and decorative images that were needlessly described. The extraction gives you the raw material; judging quality is a human review against the images and their purpose. This is exactly the audit value — seeing all the alternatives together makes weak or missing alt text obvious so you can fix it.

How does this relate to making a PDF accessible in the first place?

Extraction is the review/reuse side; creation is the authoring side. To make a PDF accessible you tag it, set reading order, write meaningful alt text, and validate — and extracting the alt text afterward is a way to verify and reuse that work. So they are two ends of the same accessibility lifecycle: author the accessibility (tags + alt text), then extract/audit it to confirm and carry it forward. If you are starting from an inaccessible PDF, the priority is creating the accessibility, after which extraction becomes a useful check. Either way, the alt text and tag structure are the substance — what a screen reader turns into the spoken experience.

Is it safe to do this with an online tool?

For confidential documents, prefer a tool that processes files locally. ScoutMyTool reads and validates PDF structure and exports content in your browser tab, so the document never leaves your machine. For sensitive documents, confirm the tool does not upload before using it.

6 min read

How to extract the accessibility text (alt text) from a PDF

By ScoutMyTool Editorial Team · Last updated: 2026-05-22

First, a clarification: a PDF’s accessibility information is text, not audio. A screen reader speaks a document by reading its text alternatives — the alt text on images and the tagged content (headings, reading order, tables, labels). So “extracting audio descriptions from a PDF” means pulling out that alt text and accessibility structure — the text a screen reader would voice — which is genuinely useful for auditing a document’s accessibility or reusing the descriptions. This guide explains what is actually there, why and how to extract it, what an empty result tells you (the PDF is not accessible), how to judge whether the alt text is any good, and how it fits the wider accessibility lifecycle.

What a screen reader speaks (and you can extract)

Element	What is spoken
Image / figure	Its alt text (the text alternative)
Headings / text	The real text, in reading order
Links	Link text / description
Tables	Cells with header associations
Form fields	Field labels / tooltips

Step by step — extract and review accessibility text

Confirm the PDF is tagged. Check with PDF/A-UA validation — no tags means no alt text to extract (and an accessibility problem).
Read the tag tree. The alt text and structure live there — pull out the per-image alt text and tagged text in reading order.
Compile into a list. Export the alt texts (e.g. to a spreadsheet) so you can review every image’s description at once.
Audit the quality. Flag blanks, placeholders (“image1”), off-point or over-long descriptions, and decorative images that were needlessly described.
Reuse where useful. Carry good alt text into another format/version of the document so the accessibility work is not lost.
Treat an empty result as a diagnosis. Nothing to extract → the PDF needs remediation; shift to creating accessibility — see PDF accessibility and WCAG AA.
Verify the spoken experience. Confirm with a screen reader that the document reads sensibly — see screen-reader accessibility.

PDF accessibility: tags, reading order, alt text.
Screen-reader accessibility: what gets spoken.
WCAG AA accessible PDF: the conformance target.
Compress without losing tags: preserving the alt text/structure.
Validate PDF/A-UA: confirming the tag structure.
PDF/A-UA validation tool: check tags in your browser.
All ScoutMyTool PDF tools: the full toolkit.

FAQ

Do PDFs have "audio descriptions"?: Not as audio. The accessibility information a PDF carries is text, not sound: a screen reader generates the speech on the fly from the document's text alternatives — chiefly the alt text on images and the tagged content (headings, reading order, table structure, link and field labels). So a PDF's "audio description" of an image is really its alt text, which the screen reader voices. (Audio description as a distinct track is a video-accessibility concept; PDFs use text alternatives instead.) So "extract audio descriptions from a PDF" practically means extracting the alt text and accessibility text — the text a screen reader would speak — which is genuinely useful for auditing or reusing a document's accessibility.
Why would I want to extract a PDF's alt text?: A few real reasons: to audit accessibility (review whether images actually have meaningful alt text, not blank or "image1"), to reuse the descriptions (e.g. when converting the document to another format and wanting to carry the alt text over), to quality-check a remediation (confirm the alt text you added is present and correct), or to inventory what a screen-reader user would hear. Pulling the text alternatives out into a list lets you review them all at once rather than clicking each image. So extraction supports accessibility review and reuse — checking that the spoken experience of the document is actually good, and carrying that work forward.
How do I extract the alt text and accessibility content?: The alt text and structure live in the PDF's tag tree (the tagged-PDF structure that makes it accessible), so you read that structure to pull out the alt text per image and the tagged text in reading order. Accessibility/PDF tools that expose the tag tree let you see and export the alternative text and structure; you can compile the image alt texts into a list to review. If the PDF is not tagged at all, there is no alt text or structure to extract (it is not accessible in the first place) — which is itself a finding. So extraction works on tagged PDFs by reading their accessibility structure; an untagged PDF has nothing to extract, signalling it needs remediation.
What if the PDF has no tags or alt text?: Then there is nothing to extract, and that is the headline result: an untagged PDF (or images with no alt text) is not accessible, and a screen reader would skip the images or read nothing meaningful for them. So an extraction that comes back empty is telling you the document needs accessibility remediation — adding tags, reading order, and alt text — not that the tool failed. At that point the task shifts from extracting accessibility content to creating it: tag the document and write alt text. So treat an empty extraction as a diagnosis: the PDF lacks the accessibility layer and needs it added before it can serve screen-reader users.
How do I judge whether the extracted alt text is any good?: Review the extracted descriptions against what each image actually conveys: good alt text concisely describes the image's meaning/function in context, not "image" or a filename, and decorative images should be marked as such (empty alt) rather than described. So scan your extracted list for blanks where there should be descriptions, unhelpful placeholders, overly long or missing-the-point descriptions, and decorative images that were needlessly described. The extraction gives you the raw material; judging quality is a human review against the images and their purpose. This is exactly the audit value — seeing all the alternatives together makes weak or missing alt text obvious so you can fix it.
How does this relate to making a PDF accessible in the first place?: Extraction is the review/reuse side; creation is the authoring side. To make a PDF accessible you tag it, set reading order, write meaningful alt text, and validate — and extracting the alt text afterward is a way to verify and reuse that work. So they are two ends of the same accessibility lifecycle: author the accessibility (tags + alt text), then extract/audit it to confirm and carry it forward. If you are starting from an inaccessible PDF, the priority is creating the accessibility, after which extraction becomes a useful check. Either way, the alt text and tag structure are the substance — what a screen reader turns into the spoken experience.
Is it safe to do this with an online tool?: For confidential documents, prefer a tool that processes files locally. ScoutMyTool reads and validates PDF structure and exports content in your browser tab, so the document never leaves your machine. For sensitive documents, confirm the tool does not upload before using it.

Citations

Wikipedia — “Alt attribute,” the alt text concept screen readers voice. en.wikipedia.org/wiki/Alt_attribute
Wikipedia — “Screen reader,” which turns the text alternatives into speech. en.wikipedia.org/wiki/Screen_reader
Wikipedia — “PDF/UA” (ISO 14289), the PDF accessibility standard. en.wikipedia.org/wiki/PDF/UA

Audit what a screen reader actually hears

Validate tags and review a PDF’s alt text with ScoutMyTool’s in-browser tools — the document never leaves your machine. An empty result means it needs remediation.

Open PDF/A-UA Validation →