Previewing Files


To preview an item, simply click on the item's name. It will open directly within the Box interface. When an individual follows a shared link to a file, by default they will preview the file in Box rather than downloading or viewing the file directly.


This is the preview screen:

Preview screen annotated.png



  1.  Filename and parent folder: See the name of the file you are previewing as well as the name of that file's parent folder. You can click on the name of the parent folder to navigate back to it. 
  2. Primary file actions: From the header, you have the following actions available to you (note that some actions may be limited based on user permission level):  
    • View Recent Activity: View avatars of users who recently edited, commented on, or viewed the the file.
    • Show/Hide sidebar: Click the speech bubble icon to hide or show the sidebar.
    • Open: Click this button to open the file on your desktop. The file will be opened by the default desktop program for a given file type. Saving the file in the desktop application will automatically upload a new version to Box, so you don't have to worry about losing your changes.
    • Download: Download the file to your computer. 
    • Share: Click this button to generate a shared link to this file.
  3. Sidebar: View version history, comments, and tasks associated with the file under the Activity tab, and view the file description, metadata, and access stats under the Details tab.  More information on metadata in Box.
  4. Comment/Approval box: Leave a comment or assign an approval task by typing in the box at the bottom of the screen You can tag users in your organization by typing @ before their name. Check Add Approval to assign an approval task.  
  5. File navigation (on hover): Click the left/right arrows to move between files within a folder. You can also use the left and right arrow keys on your keyboard to navigate between files.  
  6. Preview Controls (on hover): Zoom out, zoom in, rotate, or view your file in fullscreen mode using this toolbar. Options may vary based on file type. 

Previewing Video Files


When previewing video files, you can use keyboard shortcuts to perform basic actions. Preview also supports closed captioning in videos and will work with screen reader programs (e.g. Mac's VoiceOver) for accessibility. See the following articles for more information: 





What file types are supported?


This list of file types is only applicable to the Box web and mobile apps. To learn about the file types supported through Box Platform APIs, please see our developer documentation here:


Text-Based Documents

as, as3, asm, bat, c, cc, cmake, cpp, cs, css, csv, cxx, diff, doc, docx, erb, gdoc, groovy, gsheet, h, haml, hh, htm, html, java, js, json, less, log, m, make, md, ml, mm, msg, numbers, ods, odt, pages, pdf, php, pl, plist, properties, py, rb, rst, rtf, sass, scala, scm, script, sh, sml, sql, tsv, txt, vi, vim, webdoc, wpd, xhtml, xls, xlsm, xlsx, xml, xsd, xsl, yaml



gslide, gslides, key, odp, ppt, pptx


ai,* bmp, dcm, eps, gif, gif, heic, jpeg, jpg, png, ps, psd, svg, svs, tga, tif, tiff

 *Illustrator files need to be saved in PDF compatible mode in order to preview them in Box.



  • Image files do not have an option to "Print" from Box's preview. Images will need to be downloaded to be printed.


Audio Files

aac, aif, aifc, aiff, amr, au, flac, m4a, mp3, ra, wav, wma


Video Files

3g2, 3gp, avi, flv, m2ts, m2v, m4v, mkv, mov, mp4, mpeg, mpg, mts, ogg, qt, ts, wmv



  • Video Preview is only available to Business level Box accounts and above. Free or personal users can preview video files owned by these accounts.

  • You can preview videos up to 3.5 hours in length

  • AVCHD (Advanced Video Coding High Definition) is not supported in preview.


3D (Graphics and Modeling) Files*

3ds, box3d, dae, fbx, obj, ply, stl



  • 3D Preview is only available to Business level Box accounts and above. Free or personal users can preview 3D files owned by these accounts.


Is there a file size limit for Preview?

Preview is limited to files sized 500MB or smaller, except video files, which can be as long as 3.5 hours. Excel file previews are also limited to sheets that are less than ~100 columns and ~100,000 rows.  More on the Excel online previewer.


What resolutions does Box Preview support for video previews?

Both 480p and 1080p previews are supported and end users can adjust the resolution via the settings gear when previewing a video.


My file isn't displayed properly

Preview should display most documents without issue, but we can not guarantee perfect accuracy. If your file isn't displaying properly in preview, try opening the file using it's native desktop application.


Known Limitations:

  • Excel preview does not follow time information in the original file. When previewing Excel documents in Box, the time-related functions (for example, TODAY() or TIME()) does not display accurately. This is because Excel date/time functions are dynamic while the previewed document is static. Box preview obtains and displays the date when the file was previewed. A static version of the time/date is displayed in the previewed document, based on the time when the preview was generated.
  • Password protected files cannot be previewed. 
  • Hyperlinks are not currently clickable in PowerPoint files in Box preview on the Web application,, or mobile applications. 
  • Videos embedded in Powerpoint files will not work in Preview.
  • Adobe PDF Portfolios are not supported by Box Preview at this time.