PdfNetStack and iText compared

iText Core is a broad PDF library for .NET and Java, with add-ons for HTML, OCR, redaction, complex scripts and file size optimization. PdfNetStack is an MIT licensed .NET library centred on lossless compression and editing. Since 1.1 it also creates documents, fills forms, signs documents, writes PDF/A, extracts text and converts HTML to PDF. This page sets the two side by side.

What each does well

iText. Its README describes “a high-performance, battle-tested library that allows you to create, adapt, inspect and maintain PDF documents”: creation with a layout engine, manipulation such as merging, digital signing, form creation and editing, PDF/A and PDF/UA, FIPS compliant cryptography, barcodes and SVG (repository). Add-ons extend it: pdfHTML converts HTML and CSS to PDF, pdfOCR performs OCR, pdfSweep redacts, pdfCalligraph adds scripts such as Arabic, Hebrew and Thai, pdfOptimizer reduces file size and pdfXFA flattens XFA forms (repository). pdfOptimizer has preset profiles, one of them lossless, and can revert a file or image that grew (pdfOptimizer). Text extraction is part of the kernel API (PdfTextExtractor).

PdfNetStack. By default it makes existing PDFs smaller without changing a rendered pixel, and proves every output equivalent to its source before returning it (compression, fidelity). Version 1.0 edits, merges, splits and encrypts documents. Version 1.1 adds a drawing canvas, embedded OpenType fonts with Arabic and right to left shaping, forms, PAdES B-B to B-LTA signatures, PDF/A output, text and image extraction, HTML and CSS to PDF, OCR and opt-in lossy image options. Version 1.2 adds hyphenation and a Tesseract OCR engine. All three versions are on NuGet.

Licensing in plain words

• iText. Dual licensed: AGPL-3.0 or a commercial license (repository). iText’s AGPL page says: “You may not deploy it on a network without disclosing the full source code of your own applications under the AGPL license.” The same page says you must disclose changes to iText, include the iText copyright and the AGPL license in output file metadata, and keep the producer line in every PDF created or manipulated with iText. “If you cannot comply with the AGPLv3 terms, we offer commercial licensing options” (iText AGPL page). The pdfHTML package on NuGet also gives the AGPL as its license (NuGet).
• PdfNetStack. MIT for its code, in every package. The packages that bundle the OCR models (PdfNetStack.Ocr.Models, PdfNetStack.Ocr.Tool) add Apache-2.0 for the models, and PdfNetStack.Hyphenation keeps the permissive terms of each pattern set, listed in its license file.

Read each license yourself, or ask your counsel, before you decide. This page is not legal advice.

Features

	PdfNetStack	iText Core 9.8.0 and add-ons
License	MIT	AGPL-3.0 or commercial
Targets	.NET 8 and 10, .NET Standard 2.0	.NET Framework 4.6.1, .NET Standard 2.0
Create documents	1.1: canvas, fonts, paragraphs	Yes, with a layout engine
Edit and merge	1.0	Yes
Compress existing PDFs	1.0, lossless by default; 1.1 adds opt-in lossy image options	pdfOptimizer add-on, with a lossless profile
Equivalence check of the output	Yes, on by default	Not listed
Forms	1.1: create, fill, flatten	Yes
XFA forms	No	pdfXFA add-on flattens them
Digital signatures	1.1: PAdES B-B to B-LTA, sign and validate	Yes
PDF/A	1.1: PDF/A-1b, 2b, 2u, 3b, 3u, 4, 4e, 4f	Yes
PDF/UA	Not claimed; tagged PDF from HTML (1.1)	Yes
Text extraction	1.1	Yes
HTML to PDF	1.1, PdfNetStack.Html	pdfHTML add-on
OCR	1.1: PdfNetStack.Ocr package; 1.2: Tesseract engine	pdfOCR add-on
Redaction	No	pdfSweep add-on
Arabic and right to left text	1.1, built in	pdfCalligraph add-on
Barcodes	No	Yes

Sources for the iText column: repository, NuGet (target frameworks of the package), add-ons on NuGet (pdfHTML, pdfOCR, pdfSweep, pdfCalligraph), pdfOptimizer, pdfXFA, PdfTextExtractor. “Not listed” means the feature is not in the product’s own documentation on the check date.

When to pick iText

• You need a feature PdfNetStack does not have: redaction, PDF/UA, XFA flattening or barcodes.
• The AGPL fits your project, or a commercial license suits you.
• You share code or knowledge with a Java team, since iText Core also exists for Java (iText for Java).

When to pick PdfNetStack

• You want MIT licensing, with no source disclosure or producer line obligations.
• You need to shrink existing PDFs losslessly, with a proof that the output matches the input.
• You want Arabic and right to left shaping, HTML to PDF, text extraction and OCR from one project under permissive licenses.

Related

• Compare overview
• Digital signatures
• HTML to PDF

Product names are trademarks of their respective owners, mentioned for reference only, without affiliation or endorsement.

Checked on 2026-11-12.