Ceereo

About

The team behind Ceereo

Ceereo is built by a small team focused on a single problem: making a PDF readable by assistive technology. The output is your own file with the accessibility layer written into it — not a conversion, not a rewrite, and not a single pixel moved.

What we do

We build and maintain a pipeline that reads a PDF's content stream and writes a conforming structure back into it: headings, paragraphs, lists, tables and figures in reading order, with running headers marked as artifacts so screen readers skip them. The result is the same file, tagged, and verified against PDF/UA.

We deliberately stay narrow. Ceereo adds structure; it never rewrites your wording, arguments or facts, and never changes how the page looks. Doing one thing well (born-digital PDFs) is what lets us treat edge cases — two-column layouts, straddling headers, tables without headers — as first-class problems rather than rounding errors, and decline scans honestly instead of tagging them badly.

We also publish guides on PDF accessibility: what tags actually do, how reading order is decided, and which laws now cover ordinary published documents.

Team

Ceereo is organised into three small teams. Each guide, engine feature, or audit check is owned by one of them.

Ceereo Engineering

Audit & remediation engine

The engineering team builds the pipeline that reads a PDF's content stream and writes a conforming tag structure back into it — marked content, reading order, artifacts and metadata. Background in document automation and the PDF and PDF/UA specifications.

Expertise

  • PDF/UA (ISO 14289) & tagged PDF
  • PDF content-stream analysis
  • Matterhorn Protocol machine checks
  • WCAG 2.2 for documents
  • Document structure analysis

Ceereo Editorial

Guides, glossary, and blog

The editorial team writes the accessibility-compliance guides on this site and maintains the glossary of PDF-accessibility terms. Every published post is reviewed against a checklist: factual accuracy against the primary sources (the DOJ Title II rule, EN 301 549, the PDF/UA and WCAG specifications), original analysis, and citations to those sources.

Expertise

  • Technical writing
  • ADA Title II & Section 508 requirements
  • European Accessibility Act / EN 301 549
  • SEO & content strategy

Ceereo Design

Verification & reporting

The design team shapes how audit findings are explained: severity triage, the 0–100 score, the before/after verification report, and the pixel-diff proof that nothing visible changed. Background in information design and accessible UX.

Expertise

  • Information design
  • Accessible UX (WCAG)
  • Audit reporting
  • Data visualization

Editorial standards

Every guide, comparison, and benchmark on this site is reviewed against the same four criteria before publication:

  1. Factually verifiable. Claims about standards, deadlines, or competitor behaviour link to primary sources (the DOJ Title II rule, the PDF/UA and WCAG specifications, the competitor's own documentation).
  2. Original analysis. Comparison and benchmark posts contain numbers we measured ourselves, with the methodology disclosed inline.
  3. Honest about trade-offs. Comparison posts include a "where the alternative wins" section. Benchmark posts publish failure modes alongside successes.
  4. Updated when wrong. When a competitor ships a feature that changes a comparison, or a benchmark result no longer holds, the post is updated and the updatedAt date is bumped.

Get in touch

For press, partnerships, factual corrections to a published post, or general enquiries, email support@ceereo.com or use the contact form. We respond within one business day.