Overleaf project: pdfua2-mathml-af-alt (read-only)
This file tests AF + Alt text: MathML is embedded as an Associated File, and a plain-text alternative (Alt text) is also auto-generated on the formula tag. No MathML Structure Elements are written into the tag tree.
| File | Description |
|---|---|
main.tex |
LaTeX source |
pdfua2-mathml-af-alt.pdf |
Compiled PDF output |
latexmkrc |
Overleaf compilation configuration (shared across all six projects) |
\DocumentMetadata configuration\DocumentMetadata{
lang=en,
tagging=on,
pdfstandard = {ua-2, A-4f},
tagging-setup={
math/setup = mathml-AF,
math/alt/use = true
}
}
Key choices:
pdfstandard = {ua-2, A-4f} — A-4f is required here because the AF method embeds MathML as a file attachment on each formula object. See the top-level README.math/setup = mathml-AF — MathML is attached as an Associated File on each formula tag.math/alt/use = true — Instructs tagpdf to also write an Alt attribute on the formula tag containing a plain-text representation of the math. This is auto-generated by the LaTeX tagging engine from the LaTeX source; it is not hand-authored alt text.lang=en — See the top-level README for the reasoning behind using en rather than en-US.| Screen reader + PDF viewer | Result |
|---|---|
| NVDA with Adobe Acrobat Pro | ❌ Alt text (static string; no interactivity) |
| JAWS with Adobe Acrobat Pro | ❌ Alt text (static string; no interactivity) |
| NVDA with Firefox | ✅ Configurable math speech/braille; interactive expression exploring |
| JAWS with Firefox | ✅ Configurable math speech/braille; interactive expression exploring |
| NVDA or JAWS with Chrome/Edge | ❌ Math is skipped over; not read aloud |
| VoiceOver macOS (all viewers) | ❌ Speaks as gibberish / math skipped |
See the full results table for complete detail and test dates.
When Alt text is present on the formula tag, Adobe Acrobat Pro reads it instead of processing the MathML — for both NVDA and JAWS. This is a consequence of how Acrobat prioritizes the Alt attribute: it treats it as the authoritative text alternative and does not pass control to a math engine. Firefox ignores the Alt attribute on formula tags and correctly routes to MathML via MathCAT.
The Alt text result is marked as a failure in the test results because it provides only a static string with no interactive navigation, no braille output configuration, and potentially reduced fidelity for complex expressions. It represents a significant step down from full MathML access even though it does convey some meaning.