How to Create Different PDF Versions in C#

IronPDF automatically manages PDF version selection based on document features, choosing versions from 1.4 to 1.7 to ensure compatibility while preserving functionality. This seamless process handles everything from simple HTML conversions (typically PDF 1.4) to complex document merging (PDF 1.7 standard). When working with PDF from HTML String conversions, IronPDF intelligently determines the appropriate version based on your content’s requirements.

Quickstart: Create Different PDF Versions in C#

```cs :title=Quickstart Example // Create a simple PDF using IronPDF - automatically selects version 1.4 using IronPdf;

var renderer = new ChromePdfRenderer(); var pdf = renderer.RenderHtmlAsPdf(""); pdf.SaveAs("hello-world.pdf");

<br class="clear">

## How Do I Create a PDF Version 1.4 Document?

<!-- TODO: Add image here -->
<!-- ![Diagram illustrating pdf version 1.4 example implementation](/static-assets/images/TODO/pdf-version-1-4-example-code_illustration.webp) -->
<!-- Description: Diagram or screenshot illustrating the code concept -->

IronPDF supports all PDF versions from 1.2 to 1.7. When converting HTML to PDF, IronPDF automatically selects the lowest version offered by the Chromium engine, ranging from PDF 1.4 to PDF 1.6, to maximize compatibility. This behavior matches what you’ll find when [exporting different PDF versions](https://ironpdf.com/how-to/pdf-versions/) in various applications.

Most conversions result in PDF 1.4. PDF 1.4 features transparency support, enabling modern graphic designs while maintaining broad compatibility. In this example, we’ll convert an HTML string to PDF using IronPDF to demonstrate this behavior. This approach works seamlessly whether you’re creating PDFs from [HTML files](https://ironpdf.com/how-to/html-file-to-pdf/), [URLs](https://ironpdf.com/how-to/url-to-pdf/), or [ASPX pages](https://ironpdf.com/how-to/aspx-to-pdf/).

### What Code Do I Need to Generate PDF 1.4?

```cs
:path=/static-assets/pdf/content-code-examples/how-to/pdf-version-standard.cs

IronPDF’s intelligent version selection shines here. For basic HTML content without advanced features, it defaults to PDF 1.4, ensuring your documents work across the widest range of PDF viewers and applications. This automatic selection eliminates manual version configuration in most scenarios.

What Does the PDF 1.4 Output Look Like?

As shown, IronPDF chose the lowest version from its range (PDF 1.4) to ensure compatibility. This version supports essential features like font embedding, encryption, and basic forms while maintaining excellent compatibility with older PDF readers.

---

How Do I Create a PDF Version 1.7 Document?

IronPDF automatically generates PDF 1.7 (the international standard) when merging documents to ensure maximum compatibility. Since source PDFs may use different versions and features, defaulting to the comprehensive 1.7 standard ensures all original elements are preserved without data loss. This is crucial when merging or splitting PDFs from various sources.

PDF version 1.7 became the ISO standard (ISO 32000-1:2008) and includes advanced features:

• Enhanced security and encryption options
• 3D content support
• Advanced transparency blending modes
• Improved accessibility features
• Better Unicode support for international languages

What Code Do I Need for Merging PDFs to Version 1.7?

:path=/static-assets/pdf/content-code-examples/how-to/merge-or-split-pdfs-merge.cs

using IronPdf;

// Two paged PDF
const string html_a =
    @"<p> [PDF_A] </p>
    <p> [PDF_A] 1st Page </p>
    <div style = 'page-break-after: always;' ></div>
    <p> [PDF_A] 2nd Page</p>";

// Two paged PDF
const string html_b =
    @"<p> [PDF_B] </p>
    <p> [PDF_B] 1st Page </p>
    <div style = 'page-break-after: always;' ></div>
    <p> [PDF_B] 2nd Page</p>";

var renderer = new ChromePdfRenderer();

var pdfdoc_a = renderer.RenderHtmlAsPdf(html_a);
var pdfdoc_b = renderer.RenderHtmlAsPdf(html_b);

// Four paged PDF
var merged = PdfDocument.Merge(pdfdoc_a, pdfdoc_b);
merged.SaveAs("Merged.pdf");

Imports IronPdf

' Two paged PDF
Private Const html_a As String = "<p> [PDF_A] </p>
    <p> [PDF_A] 1st Page </p>
    <div style = 'page-break-after: always;' ></div>
    <p> [PDF_A] 2nd Page</p>"

' Two paged PDF
Private Const html_b As String = "<p> [PDF_B] </p>
    <p> [PDF_B] 1st Page </p>
    <div style = 'page-break-after: always;' ></div>
    <p> [PDF_B] 2nd Page</p>"

Private renderer = New ChromePdfRenderer()

Private pdfdoc_a = renderer.RenderHtmlAsPdf(html_a)
Private pdfdoc_b = renderer.RenderHtmlAsPdf(html_b)

' Four paged PDF
Private merged = PdfDocument.Merge(pdfdoc_a, pdfdoc_b)
merged.SaveAs("Merged.pdf")

$vbLabelText   $csharpLabel

This merging functionality is essential when combining documents from different sources or when you need to add, copy, or delete PDF pages. The resulting PDF 1.7 document ensures all features from both source documents are preserved.

Why Does IronPDF Use Version 1.7 for Merged Documents?

IronPDF generated a 1.7 version PDF by merging the two PDFs. This ensures:

1. Universal Compatibility: PDF 1.7 is supported by all modern PDF readers and browsers
2. Feature Preservation: All advanced features from source documents are maintained
3. Future-Proofing: As the ISO standard, PDF 1.7 ensures long-term document accessibility
4. Enhanced Security: Support for advanced PDF permissions and passwords