File Type Support


PSPDFKit Server has been deprecated and replaced by PSPDFKit Document Engine. All PSPDFKit Server and PSPDFKit for Web Server-Backed licenses will work as before and be supported until 15 May 2024 (we will contact you about license migration). To start using Document Engine, refer to the migration guide. With Document Engine, you’ll have access to robust new capabilities (read the blog for more information).

PSPDFKit Server supports importing documents in different file formats:

  • PDFs (available for all licenses)

  • Image documents (JPEG, PNG, and TIFF — requires a specific license component)

  • Office files (Word, Excel, and PowerPoint — requires a specific license component)

The following table shows the allowed file extensions and MIME types:

File Extension MIME Type
PDF application/pdf
DOC application/msword
DOCX application/vnd.openxmlformats-officedocument.wordprocessingml.document
XLS application/
XLSX application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
PPT, PPS application/
PPTX application/vnd.openxmlformats-officedocument.presentationml.presentation
PPSX application/vnd.openxmlformats-officedocument.presentationml.slideshow
JPG/JPEG image/jpeg
PNG image/png
TIFF image/tiff

You can create a document in any of the supported file formats and then use the functionality of both the Web API and the Server API.

For example, you can create a document starting with an Office file, add some form fields to it, and then digitally sign it.

To guarantee compatibility with all features included in PSPDFKit for Web and PSPDFKit Server, it’s only possible to export a document in PDF format. However, you can download the originally uploaded file via the PDF download API endpoint using the source=true query string parameter.

For instructions on how to upload documents in one of the supported formats, please consult the relevant guide page.

Using this requires your license to have the Office Files Support component enabled.

Conversion on Mobile Clients

If you are also using PSPDFKit for Android or PSPDFKit for iOS, you can use your running PSPDFKit Server instance to convert Office documents for use in your mobile application. This works by allowing the mobile application to upload Office files to your Server and then downloading the converted PDF file. To use this, your mobile application needs to provide a JSON Web Token (JWT) as described here. For more information, check out our Android guide and iOS guide.

When using this, also keep in mind the performance considerations outlined below, as every request will result in a conversion process being started since there is no caching involved.

Performance Considerations

To operate on an Office file, PSPDFKit Server needs to convert the file to a PDF during the document import process. For documents created by uploading a file and documents with a remote URL, conversion happens completely transparently.

No matter the document source, PSPDFKit Server will store the PDF counterpart of the original file in its configured asset storage. This is particularly relevant if you plan to use documents with remote URLs that point to Microsoft Office files.

The conversion from Office to PDF is handled by a headless LibreOffice instance included in the PSPDFKit Server Docker image. Depending on the size and complexity of the file, the conversion process can use a significant amount of CPU and memory. We recommend testing your setup with a wide range of documents and using the monitoring facilities offered by your deployment solution to make sure the load is compatible with your current infrastructure.