---
title: "C# PDF Watermark API for text and images"
canonical_url: "https://www.nutrient.io/guides/document-converter/document-converter-services/watermark/csharp/"
md_url: "https://www.nutrient.io/guides/document-converter/document-converter-services/watermark/csharp.md"
last_updated: "2026-05-19T18:11:33.863Z"
description: "Add text and image watermarks dynamically to PDFs and Office files using our easy REST API. Start your free trial today!"
---

# Add watermarks to documents with C#

### Online

[Online](https://www.nutrient.io/guides/document-converter/document-converter-services/watermark/csharp.md)

### On-Premises

[On-Premises](https://www.nutrient.io/guides/document-converter/document-converter-services/watermark/csharp-server.md)

Add text and image watermarks to PDF or Office files through our REST API. Dynamically add dates, times, and page numbers to the header and footer of your documents. Insert lines, rectangles, ellipses, barcodes, RTF files, images, and PDFs into your document. Apply multiple watermarks to the same page or to a range of pages (odd, even, portrait, or landscape). No server setup is required — simply start your free trial or sign up for an account to integrate watermarking capabilities into your application.

## Code Samples: Adding Watermarks Using C#

Explore our code samples to learn how you can add watermarks to documents in your application or workflow.

1. [Add Watermarks to PDFs in C#](https://github.com/Muhimbi/PDF-Converter-Services-Online/tree/master/clients/v1/csharp/samples/watermarking)

2. [Add Watermarks to Office Documents in C#](https://github.com/Muhimbi/PDF-Converter-Services-Online/tree/master/clients/v1/csharp/samples/watermarking%20\(MS%20Office\))

---

## Related pages

- [C# Watermark Server](/guides/document-converter/document-converter-services/watermark/csharp-server.md)
- [Add watermarks to PDFs and Office files](/guides/document-converter/document-converter-services/watermark/dotnet-core.md)
- [.NET Core Watermark Server](/guides/document-converter/document-converter-services/watermark/dotnet-core-server.md)
- [PDF Watermark API](/guides/document-converter/document-converter-services/watermark.md)
- [Java Watermark Server](/guides/document-converter/document-converter-services/watermark/java-server.md)
- [Add watermarks to your documents](/guides/document-converter/document-converter-services/watermark/java.md)
- [Add watermarks to PDFs using PHP API](/guides/document-converter/document-converter-services/watermark/php.md)
- [Add watermarks to your documents](/guides/document-converter/document-converter-services/watermark/javascript.md)