veraPDF vs PAC
Two ways to check a PDF against PDF/UA.
The short answer
Use veraPDF when you need a machine verdict at volume: it is open source, runs anywhere Java runs, and works inside a batch pipeline where nothing is clicked. Reach for PAC when a document has already passed the machine check and a person still has to judge whether it is usable - it is a free Windows application with a screen-reader preview and a structure view.
The difference that decides it
Neither is sufficient alone, and the useful pattern is both: the machine check across the whole set, then a person on the documents that matter. What a pass gives you is a floor rather than a certificate, and the gap between the two is where accessibility problems actually survive.
Side by side
7 of 10 rows differ
| Compared | veraPDF | PAC |
|---|---|---|
| Files stay on your device | No server involved | No server involved |
| Redaction | No redaction feature | No redaction feature |
| Price | Open source | Free |
| Platforms | Windows · macOS · Linux · Self-hosted | Windows |
| Open source | Yes | Not verified |
| Self-hostable | Yes | Not verified |
| Data residency | Self-hosted | Self-hosted |
| Programmatic access | Embeddable library · Command line | None |
| Owner | veraPDF Consortium | axes4 GmbH |
| Website responded | Responded in 704 ms | Responded in 1251 ms |
Rows that differ are shown in full contrast; rows where the two agree are dimmed. Every value here comes from the individual records, where each one names the page it came from - and says plainly when something has not been verified rather than filling the gap.
veraPDF
Industry-backed open source accessibility validator for PDF/A and PDF/UA conformance.
Visit veraPDF Opens the vendor's own site.
PAC
Free Windows accessibility checker for PDF/UA and WCAG, with local AI-assisted semantic checks.
Visit PAC Opens the vendor's own site.
Other comparisons
- PAC vs axesCheck The same PDF accessibility checker, twice, from the same company.