Nutrient .NET SDK vs. iText Core: Complete comparison for .NET developers

Key differences at a glance

Direct feature comparison

Nutrient vs. iText Core: Code example comparisons

The following examples show how common PDF operations differ between iText Core and Nutrient .NET SDK, from basic document creation to OCR and merging.

Example 1: Generate PDFs from scratch

iText Core approach:

using iText.Kernel.Pdf;
using iText.Layout;
using iText.Layout.Element;

// Create a new PDF document.
PdfWriter writer = new PdfWriter("output.pdf");
PdfDocument pdf = new PdfDocument(writer);
Document document = new Document(pdf);

// Add a paragraph to the document.
Paragraph para = new Paragraph("Hello World! This is a PDF created with iText 9.")
    .SetFontSize(14);
document.Add(para);

// Close the document.
document.Close();

iText Core uses a high-level API with Document, Paragraph, and layout elements. You can control PDF structure through both convenience methods and low-level manipulation.

Nutrient .NET SDK approach:

using GdPicturePDF gdpicturePDF = new GdPicturePDF();

// Set the origin to the top-left corner of the page.
gdpicturePDF.SetOrigin(PdfOrigin.PdfOriginTopLeft);

// Create a new page with the Letter size.
gdpicturePDF.NewPage(PdfPageSizes.PdfPageSizeLetter);

// Add a font and select it.
gdpicturePDF.AddStandardFont(PdfStandardFont.PdfStandardFontHelvetica);
gdpicturePDF.SetTextSize(14);

// Set the text color to black.
gdpicturePDF.SetFillColor(0, 0, 0);

// Draw text on the page.
gdpicturePDF.DrawText(72, 72, "Hello World! This is a PDF created with Nutrient .NET SDK.");

// Save the document.
gdpicturePDF.SaveToFile(@"C:\temp\output.pdf");

Nutrient creates the PDF with GdPicturePDF, adds a page with NewPage(), selects a font, and draws text with DrawText(). For richer layouts, DrawTextBox() supports alignment and wrapping within a rectangle.

Example 2: Extract text from an existing PDF

iText Core approach:

using iText.Kernel.Pdf;
using iText.Kernel.Pdf.Canvas.Parser;
using iText.Kernel.Pdf.Canvas.Parser.Listener;

// Open an existing PDF document.
PdfDocument pdfDoc = new PdfDocument(new PdfReader("document.pdf"));

// Extract text from all pages.
StringBuilder text = new StringBuilder();
for (int i = 1; i <= pdfDoc.GetNumberOfPages(); i++)
{
    ITextExtractionStrategy strategy = new SimpleTextExtractionStrategy();
    string pageText = PdfTextExtractor.GetTextFromPage(pdfDoc.GetPage(i), strategy);
    text.Append(pageText);
}

// Close the document.
pdfDoc.Close();

// Save extracted text.
File.WriteAllText("extracted.txt", text.ToString());

iText Core provides multiple extraction strategies: SimpleTextExtractionStrategy extracts text in reading order, while LocationTextExtractionStrategy preserves spatial positioning.

Nutrient .NET SDK approach:

using GdPicturePDF gdpicturePDF = new GdPicturePDF();

// Load the source document.
gdpicturePDF.LoadFromFile("input.pdf");

// Optional: Improve word boundary detection in structured documents.
gdpicturePDF.SetTextExtractionOptions(TextExtractionOptions.PreserveLayout);

// Extract text from all pages.
StringBuilder text = new StringBuilder();
for (int i = 1; i <= gdpicturePDF.GetPageCount(); i++)
{
    gdpicturePDF.SelectPage(i);
    text.Append(gdpicturePDF.GetPageText());
}

// Save the extracted text to a file.
File.WriteAllText("ExtractedText.txt", text.ToString());

Nutrient loads the PDF with LoadFromFile(). It then iterates through pages with SelectPage() and extracts text using GetPageText(). SetTextExtractionOptions(PreserveLayout) maintains the original spatial positioning of text, similar to iText’s LocationTextExtractionStrategy.

Example 3: Perform OCR on scanned PDFs

iText Core approach:

using iText.Kernel.Pdf;
using iText.Pdfocr;
using iText.Pdfocr.Tesseract4;
using System.Collections.Generic;
using System.IO;

// Note: pdfOCR is a separate add-on from iText.
// Configure OCR engine with Tesseract.
var ocrEngineProperties = new Tesseract4OcrEngineProperties();
ocrEngineProperties.SetPathToTessData(new FileInfo("path/to/tessdata"));

var tesseractEngine = new Tesseract4LibOcrEngine(ocrEngineProperties);
var ocrPdfCreator = new OcrPdfCreator(tesseractEngine);

// Perform OCR on image file and create searchable PDF.
var imageFiles = new List<FileInfo> { new FileInfo("scanned.jpg") };
using (var writer = new PdfWriter("output_ocr.pdf"))
{
    ocrPdfCreator.CreatePdf(imageFiles, writer).Close();
}

This example uses iText’s pdfOCR add-on (separate purchase) with the Tesseract 4 engine. It requires a path to Tesseract language data and supports ONNX-based ML models for Latin-based languages.

Nutrient .NET SDK approach:

using GdPicturePDF gdpicturePDF = new GdPicturePDF();

// Load the source document.
gdpicturePDF.LoadFromFile("input.pdf");

// Run the OCR process on all pages with maximum multithreading support.
gdpicturePDF.OcrPages("*", 0, "eng", "", "", 300);

// Save the result in a PDF document.
gdpicturePDF.SaveToFile(@"C:\temp\output.pdf");

Nutrient loads scanned PDFs and runs OCR on all pages using OcrPages() with image preprocessing. No additional products are needed.

Example 4: Merge multiple PDFs

iText Core approach:

using iText.Kernel.Pdf;
using iText.Kernel.Utils;

// Create output document.
PdfDocument pdfDoc = new PdfDocument(new PdfWriter("merged.pdf"));

// Merge utility.
PdfMerger merger = new PdfMerger(pdfDoc);

// Load and merge first document.
PdfDocument firstDoc = new PdfDocument(new PdfReader("document1.pdf"));
merger.Merge(firstDoc, 1, firstDoc.GetNumberOfPages());
firstDoc.Close();

// Load and merge second document.
PdfDocument secondDoc = new PdfDocument(new PdfReader("document2.pdf"));
merger.Merge(secondDoc, 1, secondDoc.GetNumberOfPages());
secondDoc.Close();

// Close the merged document.
pdfDoc.Close();

iText Core uses PdfMerger to combine PDFs. You can merge specific page ranges from each source document.

Nutrient .NET SDK approach:

// Option 1: Merge with full control over document-level options.
using GdPicturePDF firstDoc = new GdPicturePDF();
firstDoc.LoadFromFile(@"C:\temp\document1.pdf");

using GdPicturePDF secondDoc = new GdPicturePDF();
secondDoc.LoadFromFile(@"C:\temp\document2.pdf");

GdPicturePDFFactory.MergeDocuments(new[] { firstDoc, secondDoc }, out GdPicturePDF mergedDoc);
using (mergedDoc)
{
    mergedDoc.SaveToFile(@"C:\temp\merged.pdf");
}

// Option 2: Merge PDF documents by file path.
using GdPicturePDF gdpicturePDF = new GdPicturePDF();
string[] sources = new[] { @"C:\temp\document1.pdf", @"C:\temp\document2.pdf" };
gdpicturePDF.MergeDocuments(sources, @"C:\temp\merged.pdf");

// Option 3: Combine mixed file types (PDFs, images, Office documents) into a single PDF.
using GdPictureDocumentConverter gdpictureConverter = new GdPictureDocumentConverter();
IEnumerable<string> source = new List<string>(new string[] { @"C:\temp\source1.jpg", @"C:\temp\source2.xlsx" });
gdpictureConverter.CombineToPDF(source, @"C:\temp\output.pdf", PdfConformance.PDF1_5);

Nutrient’s GdPicturePDFFactory.MergeDocuments() works with loaded documents and supports merging options. For a simpler approach, MergeDocuments() on GdPicturePDF takes an array of file paths and a destination. Nutrient can also combine mixed file types — images, Office documents, and CAD files — into a single PDF using CombineToPDF().

Pricing comparison

Here’s how iText Core and Nutrient .NET SDK compare on licensing, add-on costs, and total cost of ownership.

iText Core pricing

Dual licensing model:

• AGPLv3 free for open source (must publish source code)
• Commercial license: removes AGPL requirements, includes support
• Volume-based pricing (contact for quote)

Add-on costs:

iText Core is the base product. Additional capabilities require separate add-ons:

• pdfHTML — HTML/CSS-to-PDF conversion (separate purchase)
• pdfOCR — OCR functionality (separate purchase)
• pdfXFA — XFA form flattening and dynamic form handling (separate purchase)
• pdfCalligraph — Global fonts and writing systems (separate purchase)
• pdfSweep — Advanced redaction (separate purchase)
• pdfOptimizer — Document optimization (separate purchase)

Nutrient .NET SDK pricing

Commercial licensing:

• Contact Sales for a custom quote
• Enterprise support included
• No per-developer or per-project restrictions
• Flexible licensing models available
• All features included in base license (OCR, data extraction, and multi-format support)
• Optional AI Document Processing SDK available for advanced LLM-powered extraction

Nutrient’s single license reduces procurement complexity and integration issues between components.

Total cost of ownership comparison

When iText Core costs less:

• Your application is open source (AGPLv3 license)
• You only need PDF creation and manipulation (no OCR or format conversion)
• Low-to-moderate PDF processing volume
• You don’t require add-ons

When Nutrient delivers stronger ROI:

• Faster delivery — complete document features in days instead of months
• No custom parsing — built-in data extraction for common document types
• Handle multiple formats — process any document type without additional tools
• Enterprise support with SLAs and simplified vendor management

Migration guide: iText Core to Nutrient

Migrating from iText Core to Nutrient requires API adaptation but adds document processing capabilities beyond PDF. The steps below cover installation, scope assessment, API mapping, and expanding into Nutrient’s broader feature set.

Step 1: Install Nutrient .NET SDK

Install via NuGet and configure licensing:

# Add the package (.NET 6.0 or higher)
dotnet add package GdPicture.API

# For .NET Framework 4.6.2:
dotnet add package GdPicture

using GdPicture14;

LicenseManager licenseManager = new LicenseManager();
licenseManager.RegisterKEY(""); // Empty string for trial mode

Step 2: Identify migration scope

Direct replacement: Map iText Core PDF operations to Nutrient equivalents

Feature expansion: Use Nutrient’s OCR, extraction, and multi-format capabilities beyond PDF

Hybrid approach: Use iText Core for specific PDF operations, Nutrient for document processing

Step 3: API mapping

Common iText Core patterns and Nutrient equivalents:

Step 4: Add document processing features

After migrating core PDF functionality, add Nutrient’s document processing features:

• OCR — Example 3 shows built-in OCR without separate add-ons
• Data extraction — Extract data from forms, tables, and key-value pairs
• Multi-format — Convert documents to PDF (Office, images, and CAD)
• Compliance — Full PDF/A support for archival standards

Migration effort estimate

Use case recommendations

Community vs. enterprise support: iText offers an open source community with third-party examples and StackOverflow discussions, plus commercial support options. Nutrient provides commercial support with SLAs and direct vendor communication.

Hybrid approach: Some teams use both libraries — iText Core for PDF generation and standards compliance, and Nutrient for OCR, extraction, and multi-format conversion. This requires managing two SDKs and licenses.

Conclusion

The decision comes down to scope.

If your application only generates or manipulates digital PDFs, iText Core delivers granular control with flexible licensing. For open source projects, AGPLv3 makes it accessible. For commercial apps, modular pricing lets you add capabilities as needed.

If your application processes scanned documents, extracts data from forms, or handles mixed file types, Nutrient eliminates the integration work. Teams ship production-ready document processing without building OCR pipelines, extraction parsers, or format converters.

Bottom line: iText Core is a PDF library. Nutrient is a document processing platform. Choose based on what you’re building.

Try Nutrient free or contact Sales for a custom ROI analysis.

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