Document Preview

As an administrator, you can provide preview tools to your users so that they can quickly view a portion of a document to determine if it is the one they need to work with. 

 1. After selecting a file in the User Portal, a Preview button is available.

 2. After clicking the Preview button,
a separate window opens showing an image of the file.

The preview can be edited with the same Web edit/Office Online and Edit in Desktop applications that are available for editing the file from the file listing.

There are a few different ways an administrator can provide preview tools in FileCloud:

  • Enable Quick JS Preview (FileCloud version 19.1 and later)
  • DocConverter with LibreOffice (FileCloud version 18.2 and earlier)
  • WOPI - Web Application Open Platform Interface Protocol (Supports online web editing features)
  • Integration with AutoDesk Viewer (FileCloud version 22.1 and later) for previewing AutoCAD files only. See Setting Up AutoCAD File Preview with Autodesk Viewer for instructions.

FileCloud uses a Java-based service called FileCloud Document Converter to:

  • Enable thumbs for all Microsoft Office documents (DOC, DOCX, PPT, PPTX, XSL, XSLX)
  • Enable thumbs for Adobe documents (AI, PDF, PSD)
  • Enable thumbs for TIFF images
  • Interface with LibreOffice for document preview generation

For this FileCloud uses a java program based on Apache's PDFBox.  Document converter also will use LibreOffice libraries to convert documents to PDF.

FileCloud version 19.1 and later already includes the Doc Converter jar file and it is installed automatically. 

  • You do not need to download it as you did in earlier versions.

1.   Start the Doc Converter service and configure it with FileCloud.

Linux: LibreOffice Ubuntu/RHEL Instructions

Windows: LibreOffice Windows Instructions

2.   Enable thumbnail images on the Admin Portal.

Enable Document Thumbs

Administrators can configure online editing to allow FileCloud users to select any supported document and edit the document from within the User Portal.

  • FileCloud uses the WOPI (Web Application Open Platform Interface) protocol to support online web editing

To use WOPI, you must install or have already available one of the following to provide the web editing capability:

  • Microsoft Office Online
  • Collabora Code

Manage Online Web Editing

You can choose which tool to use not only by the version of FileCloud you are using, but also by the functionality.

ToolFile Types PreviewedPreview Keys  Interactions with Other Tools/Other Notes
Quick JS Preview
  • DOCX
  • PPTX
  • XLSX
  • PDF
  • video: MP4, WebM, MOV
  • audio: MP3, OGG, WAV, M4A
  • AI
  • PSD
  • If DocConverter is also in use, then previews can also be shown by using the SHIFT + Preview keys for a DocConverter view
  • If WOPI is also in use, then WOPI will override QuickJS functionality
  • Both QuickJS and DocConverter must be in use to enable users to preview Office files. See LibreOffice Windows Instructions.
DocConverter with LibreOffice
  • TXT
  • ODT (OpenDocument text created by LibreOffice and others)
  • ODG (Oasis graphic files)
  • ODS (Oasis spreasheets)
  • PDF
  • video: MP4, WebM, MOV
  • audio: MP3, OGG, WAV, M4A
  • AI
SHIFT + Preview
  • If Quick JS is also in use, then previews can also be shown without using any preview keys
  • If WOPI is also in use, then WOPI will override DocConverter functionality
  • video: MP4, WebM, MOV
  • audio: MP3, OGG, WAV, M4A
  • WOPI will override any Quick JS or DocConverter functionality
  • To preview a file using WOPI, the user must have download permission to the file.

(lightbulb) To configure document preview, click on a method to see the steps:

PRE-REQISITES for Quick JS Previews:

  1. You must be running FileCloud version 19.1 and later.
  2. You must stop the Document Converter service according to the OS you are using.
    1. For Windows, open the FileCloud Control Panel and stop the DocConverter Service if it is running.
    2. For Linux, run the following command:

      # sudo service fcdocconverter stop

To provide a preview using Quick JS:

  1. Open a browser and log in to the Admin Portal.
  2. From the left navigation panel, under SETTINGS, click Settings.
  3. On the Manage Settings  window, select the Misc.  tab, and then the Preview  tab.
  4. On the Preview screen, next to Enable Quick JS Preview, select the checkbox. 

     1.  Install OpenJDK:


 1.   Download Open JDK 8 from


 2.   Create a new folder in the C: directory.

(In the example diagram, jdk8u192-b12 is the name of the new folder.)

3.   Extract the Open JDK file you downloaded into the new folder.

     2.  Install Document Preview

             a.  Open FileCloud Control Panel.

             b.  To install Document Preview, click Install.

     3.  Start the Service:

               a.  Open FileCloud Control Panel.

               b.  To start the Document Preview service, click Start.

     4. Configure FileCloud

(warning)  If you are running the multi-site configuration, please follow these steps on the root site.

               a.  Open a browser and log in to the Admin Portal.

               b.  From the left navigation panel, under SETTINGS click Settings.

               c.  On the Manage Settings screen, select the Misc. sub-tab.

               d.  In Office Location, type in the correct path for the Libre Office portable installation. Normally you would type in the following path:


                e.  Next to Enable FC Document Converter , select the checkbox.

Administrators can configure online previewing using WOPI for any supported document from within the User Portal.

  1. In the Admin UI, go to Settings > Web Edit tab.
  2. Configure online editing using WOPI at 
    Microsoft Office Online Cloud For Web Edit
  3. During your configuration, check WOPI Preview.

To include watermarks on previewed documents, see Enabling Watermarks On Previews