Document & File Conversion APIs for .NET & Java

Programmatically convert Word, Excel, PowerPoint, PDF, CAD, HTML, images & more into 100+ formats. Conholdate.Total APIs for .NET & Java let you batch convert files, apply watermarks, and customize output — without relying on Microsoft Office or Adobe Acrobat. Or use our free online conversion tool.

Download Free Trial

Universal File Conversion Libraries for Developers

Conholdate.Total for .NET & Java provides enterprise-grade APIs to convert more than 100 document and image formats. Transform entire documents or specific pages, preserve layout and formatting, apply watermarks, or extract metadata. The API is scalable, lightweight, and independent of Microsoft Office or Adobe Acrobat — making it ideal for building cloud apps, desktop tools, or automated workflows.

Key Conversion Features

Wide Format Support

Convert Microsoft Word, Excel, PowerPoint, Outlook, PDF, OpenOffice, Visio, OneNote, HTML, images, CAD/3D formats, eBooks, emails, and more into popular output types like PDF, DOCX, XLSX, PPTX, PNG, JPEG, or SVG.

Customizable Output

Control page ranges, orientation, margins, font embedding, color schemes, and watermarking. Preserve hyperlinks, headers, footers, and generate tables of contents automatically.

Watermarking Options

Add text or image watermarks with custom position, rotation, transparency, and layering options.

Extract Document Information

Retrieve rich metadata: author, title, encryption status, word count, attachments in emails, CAD layers, project dates, or spreadsheet worksheets.

Faster Performance with Caching

Use built-in caching for repeated conversions to improve performance with large or complex files.

No Microsoft Office Dependency

Fully managed codebase — no need to install Office or Acrobat. Safer, faster, and scalable alternative for production apps.

Cross-Platform APIs

Available for .NET (C#, VB.NET) and Java, working seamlessly in Windows, Linux, Docker, and cloud environments.

Developer Productivity

Clean, intuitive API design works smoothly with Visual Studio, IntelliJ IDEA, and Eclipse. Easy integration into CI/CD pipelines.

FAQs

Can I try document conversion without coding?

Yes. Use our Free Online Document Converter to test conversions instantly.

What file formats are supported?

Over 100, including Word, Excel, PowerPoint, PDF, HTML, images, CAD, eBooks, emails, archives, and more.

Do I need Microsoft Office or Adobe Acrobat installed?

No. Conholdate.Total APIs run independently without third-party software.

Can I convert specific pages instead of the whole file?

Yes. You can convert selected page ranges, single pages, or the entire document.

Is the original formatting preserved?

Yes. Layout, fonts, images, and hyperlinks are preserved in the converted document.

Can I use this API in cloud or container environments?

Absolutely. The library works in Docker, Kubernetes, Azure, AWS, GCP, and on-premise systems.

Is it suitable for large enterprise files?

Yes. With caching and scalable architecture, it handles large and complex files efficiently.

Can I batch convert multiple files?

Yes. The API supports batch operations for efficient document processing.