The ADA Title II rule is format-neutral. WCAG 2.1 Level AA can be achieved in tagged PDF, HTML, or other formats. So what should agencies actually choose for their public documents? The answer is "mostly HTML, with a few exceptions." Here's why.
The cost reality
Per-page accessibility remediation pricing in the U.S. market falls in two ranges, and the gap between them is enormous:
- Manual PDF remediation: $5–$25 per page, depending on complexity and vendor. A 50,000-page corpus runs $250,000–$1,250,000.
- Automated PDF-to-HTML conversion: $0.05–$0.50 per page using AI tools. The same 50,000-page corpus runs $2,500–$25,000.
The 100–500x cost gap exists because manual PDF remediation requires a trained human to open every document, build a tag tree, audit reading order, and verify accessibility. Automated HTML conversion can produce semantically tagged output at machine speeds, then validated programmatically.
The accessibility reality
Even when both formats meet WCAG 2.1 AA, screen reader users overwhelmingly prefer HTML. Common reasons:
- Reading order is reliable. HTML reading order matches the DOM. PDF reading order depends on the tag tree, which can drift from visual order in complex layouts.
- Reflow works. HTML reflows to any screen size, font size, or zoom level. PDF reflow is supported but unevenly across viewers.
- Search and navigation are native. Screen readers expose HTML headings and landmarks as native navigation. Users can jump by H2, by region, by link.
- Forms work. HTML form fields are first-class accessible elements. PDF forms work but lag behind.
When PDF still makes sense
PDFs are not obsolete. There are three categories where PDF remains the right choice:
1. Documents with strict legal formatting
Court filings, signed contracts, executed ordinances, and recorded resolutions need exact reproduction of the original. The PDF is the legal record; the HTML is a derivative.
2. Forms designed to be printed and physically signed
If users will print the form, fill it by hand, and submit it (e.g., paper applications for in-person service centers), the PDF needs to remain the canonical version.
3. Multi-page graphical documents
Maps, plans, technical drawings, and posters where the visual layout is the content (not just a presentation of underlying data) work better in PDF. Even then, an HTML companion page summarizing the content is best practice.
The rule of thumb: if the document is text-and-tables that conveys information, publish HTML and offer PDF as an optional download. If the document is a graphical or legal artifact, publish PDF and provide an HTML summary.
Hybrid: HTML primary, PDF download
The pattern most agencies converge on is hybrid. The webpage shows accessible HTML by default. A "Download PDF" button preserves the original document for offline use, printing, or legal records. Both versions exist; the user chooses.
This pattern has practical advantages:
- Compliance moves to the HTML. If your HTML version is WCAG 2.1 AA, you've met your accessibility obligation. The PDF download can remain a non-accessible reference.
- Search engines index the HTML. PDFs are searchable but rank lower and provide poorer snippets. HTML content surfaces in Google with proper titles and meta descriptions.
- Mobile users get a native experience. 60%+ of public agency website traffic is mobile. PDFs on mobile are painful; HTML is native.
- Maintenance is easier. Updates to a single HTML page are quick. Updating a PDF requires regenerating, re-tagging, and re-uploading.
What about the people who insist on PDF?
Internal stakeholders — especially elected officials, attorneys, and longtime staff — sometimes insist documents must remain as PDF. The strongest case for PDF is "this is the official record." That's true for some documents (executed ordinances, certified plans). It's not true for most.
A useful framing: the official record can stay PDF, but the public-facing version on your website should be HTML. The HTML satisfies the ADA obligation. The PDF satisfies the records-management obligation. Both can coexist.
The decision framework
For each document type your agency publishes, ask:
- Is the document primarily text and tables conveying information? → HTML primary, PDF download.
- Is the document a legal record that must remain in original form? → PDF, with an HTML summary or transcript.
- Is the document a form users will print and submit on paper? → Tagged PDF.
- Is the document a map, drawing, or chart-heavy artifact? → PDF with HTML alternative description.
- Is the document time-sensitive or frequently updated (agendas, news, meeting materials)? → HTML primary.
What about converting your existing PDFs?
Most agencies have years of accumulated PDFs that predate the rule. Converting them to HTML automatically (with a tool like SentraCheck's PDF-to-HTML converter) is dramatically cheaper than manually remediating them. The conversion preserves the content, generates semantic HTML, and meets WCAG 2.1 AA — while keeping the original PDF available for download where useful.
For agencies with 50,000+ pages of PDF content, this single decision — convert vs. remediate in place — can be the difference between a $25,000 compliance project and a $500,000 one.