Different profiles exist because not all archival or accessibility needs are the same. PDF standards evolve, and each profile targets a specific use case, level of strictness, or generation of the standard. veraPDF mirrors these distinctions so it can validate documents accurately against the exact rule set they claim to conform to.
Why there are different profiles
Different versions of the PDF/A standard PDF/A-1, -2, -3, and -4 were introduced at different times. Each version adds or removes features (e.g., attachments, layers, engineering data, new PDF 2.0 rules). A single profile wouldn’t be able to reflect all these variations.
Different strictness levels Some workflows need full accessibility and semantic structure (A-level). Others only need the document to display correctly in the future (B-level). Some need reliable text extraction without full tagging (U-level).
Different intended uses Archiving, accessibility, engineering content, file containers, or content reuse all require different rules. Profiles let software validate exactly the scenario a document was created for.
Separate standards beyond PDF/A PDF/UA (accessibility) and WTPDF (web-friendly PDF standards) define their own requirements, so they get their own profiles.
What the profiles represent
PDF/A (archival profiles)
Used for long-term preservation. The “parts” reflect generations of the standard:
- PDF/A-1: earliest, most restrictive.
- PDF/A-2: adds modern features (transparency, JPEG2000, layers, etc.).
- PDF/A-3: allows attaching non-PDF files.
- PDF/A-4: aligns with PDF 2.0 and simplifies levels.
Each part may include levels like:
- A (Accessible) — full tagging and structure.
- B (Basic) — visual preservation only.
- U (Unicode) — ensures extractable text.
So the profiles (1a, 1b, 2a, 2b, 2u…) are veraPDF’s way to validate the exact combination of part + level.
PDF/UA (accessibility profiles)
Focused entirely on ensuring documents are usable with assistive technologies.
- ua1: first accessibility standard.
- ua2: updated for PDF 2.0.
These profiles check only accessibility requirements, not archival ones.
WTPDF (web-technology PDF)
A newer specification aimed at structured, reusable, and accessible content for digital use.
- wt1r: emphasizes clean content reuse.
- wt1a: accessibility-focused for web/pdf hybrid workflows.
In short
- Parts represent versions of the standard.
- Levels represent strictness and purpose.
- UA and WTPDF exist for accessibility and modern web compatibility.
- veraPDF provides a profile for each combination so validation matches the document’s intended claim.