Accessible PDF (Tagged PDF) and PDF/A

HtmlToPdf converter = new HtmlToPdf();

// produce a document that declares PDF/UA-1 (tagging is enabled automatically)
converter.Options.AccessibilityStandard = PdfUAStandard.UA1;
converter.Options.Title = "Quarterly Report";
converter.Options.Language = "en-US";

PdfDocument doc = converter.ConvertUrl("https://www.example.com");
doc.Save("accessible.pdf");
doc.Close();

Dim converter As New HtmlToPdf()

' produce a document that declares PDF/UA-1 (tagging is enabled automatically)
converter.Options.AccessibilityStandard = PdfUAStandard.UA1
converter.Options.Title = "Quarterly Report"
converter.Options.Language = "en-US"

Dim doc As PdfDocument = converter.ConvertUrl("https://www.example.com")
doc.Save("accessible.pdf")
doc.Close()

HtmlToPdf converter = new HtmlToPdf();

// PDF/A-3A is archival AND accessible (tagging is enabled automatically)
converter.Options.PdfStandard = PdfStandard.PdfA3A;
converter.Options.AccessibilityStandard = PdfUAStandard.UA1;
converter.Options.Title = "Invoice 2026-0042";
converter.Options.Language = "en-US";

PdfDocument doc = converter.ConvertUrl("https://www.example.com/invoice");
doc.Save("invoice-pdfa3a.pdf");
doc.Close();

Dim converter As New HtmlToPdf()

' PDF/A-3A is archival AND accessible (tagging is enabled automatically)
converter.Options.PdfStandard = PdfStandard.PdfA3A
converter.Options.AccessibilityStandard = PdfUAStandard.UA1
converter.Options.Title = "Invoice 2026-0042"
converter.Options.Language = "en-US"

Dim doc As PdfDocument = converter.ConvertUrl("https://www.example.com/invoice")
doc.Save("invoice-pdfa3a.pdf")
doc.Close()

// create an accessible PDF/A-3A document
PdfDocument doc = new PdfDocument(PdfStandard.PdfA3A);
doc.AccessibilityStandard = PdfUAStandard.UA1;
doc.Language = "en-US";
doc.Title = "Accessible Document";

PdfPage page = doc.AddPage();

// embedded fonts are required for tagged / PDF/A output
PdfFont headingFont = doc.Fonts.Add(
    new PdfSystemFont("Arial", 16f, PdfFontStyle.Bold));
PdfFont bodyFont = doc.Fonts.Add(new PdfSystemFont("Arial", 11f));

// a heading
PdfTextElement heading = new PdfTextElement(10, 10, "Annual Report", headingFont);
heading.TagType = PdfTagType.Heading1;
page.Add(heading);

// a paragraph
PdfTextElement para = new PdfTextElement(10, 40, 480,
    "This document is tagged for accessibility.", bodyFont);
para.TagType = PdfTagType.Paragraph;
page.Add(para);

// a figure with alternate text
PdfImageElement figure = new PdfImageElement(10, 90, "chart.png");
figure.TagType = PdfTagType.Figure;
figure.AlternateText = "Sales grew 20% year over year";
page.Add(figure);

// a decorative rule (excluded from the structure)
PdfLineElement rule = new PdfLineElement(10, 80, 480, 80);
rule.Artifact = true;
page.Add(rule);

doc.Save("created-accessible.pdf");
doc.Close();

' create an accessible PDF/A-3A document
Dim doc As New PdfDocument(PdfStandard.PdfA3A)
doc.AccessibilityStandard = PdfUAStandard.UA1
doc.Language = "en-US"
doc.Title = "Accessible Document"

Dim page As PdfPage = doc.AddPage()

' embedded fonts are required for tagged / PDF/A output
Dim headingFont As PdfFont = doc.Fonts.Add(
    New PdfSystemFont("Arial", 16F, PdfFontStyle.Bold))
Dim bodyFont As PdfFont = doc.Fonts.Add(New PdfSystemFont("Arial", 11F))

' a heading
Dim heading As New PdfTextElement(10, 10, "Annual Report", headingFont)
heading.TagType = PdfTagType.Heading1
page.Add(heading)

' a paragraph
Dim para As New PdfTextElement(10, 40, 480,
    "This document is tagged for accessibility.", bodyFont)
para.TagType = PdfTagType.Paragraph
page.Add(para)

' a figure with alternate text
Dim figure As New PdfImageElement(10, 90, "chart.png")
figure.TagType = PdfTagType.Figure
figure.AlternateText = "Sales grew 20% year over year"
page.Add(figure)

' a decorative rule (excluded from the structure)
Dim rule As New PdfLineElement(10, 80, 480, 80)
rule.Artifact = True
page.Add(rule)

doc.Save("created-accessible.pdf")
doc.Close()

doc.BeginTag(PdfTagType.Table);
    doc.BeginTag(PdfTagType.TableRow);
        page.Add(new PdfTextElement(10, 40, "Region", bodyFont)
            { TagType = PdfTagType.TableHeader });
        page.Add(new PdfTextElement(80, 40, "Sales", bodyFont)
            { TagType = PdfTagType.TableHeader });
    doc.EndTag();
    doc.BeginTag(PdfTagType.TableRow);
        page.Add(new PdfTextElement(10, 60, "North", bodyFont)
            { TagType = PdfTagType.TableDataCell });
        page.Add(new PdfTextElement(80, 60, "100", bodyFont)
            { TagType = PdfTagType.TableDataCell });
    doc.EndTag();
doc.EndTag();

doc.BeginTag(PdfTagType.Table)
    doc.BeginTag(PdfTagType.TableRow)
        Dim h1 As New PdfTextElement(10, 40, "Region", bodyFont)
        h1.TagType = PdfTagType.TableHeader
        page.Add(h1)
        Dim h2 As New PdfTextElement(80, 40, "Sales", bodyFont)
        h2.TagType = PdfTagType.TableHeader
        page.Add(h2)
    doc.EndTag()
    doc.BeginTag(PdfTagType.TableRow)
        Dim d1 As New PdfTextElement(10, 60, "North", bodyFont)
        d1.TagType = PdfTagType.TableDataCell
        page.Add(d1)
        Dim d2 As New PdfTextElement(80, 60, "100", bodyFont)
        d2.TagType = PdfTagType.TableDataCell
        page.Add(d2)
    doc.EndTag()
doc.EndTag()

// PDF/A-3B is the archival level that allows embedded files
HtmlToPdf converter = new HtmlToPdf();
converter.Options.PdfStandard = PdfStandard.PdfA3B;
PdfDocument doc = converter.ConvertUrl("https://www.example.com/report");

// embed the data the report was produced from
using (FileStream data = File.OpenRead("figures.csv"))
{
    doc.AddAssociatedFile(data, "figures.csv",
        PdfAttachmentRelationship.Source, "text/csv", "Source data");
}

doc.Save("report-with-data.pdf");
doc.Close();

' PDF/A-3B is the archival level that allows embedded files
Dim converter As New HtmlToPdf()
converter.Options.PdfStandard = PdfStandard.PdfA3B
Dim doc As PdfDocument = converter.ConvertUrl("https://www.example.com/report")

' embed the data the report was produced from
Using data As FileStream = File.OpenRead("figures.csv")
    doc.AddAssociatedFile(data, "figures.csv",
        PdfAttachmentRelationship.Source, "text/csv", "Source data")
End Using

doc.Save("report-with-data.pdf")
doc.Close()