Uploading Excel files to SPO via CSOM is exponentially slower than uploading Word files of the same size RRS feed

  • Question

  • We have a SharePoint app that works with Excel and Word template documents and saves them to SharePoint 365 Document Library. We use CSOM FileCreationInformation class and File.SaveBinaryDirect for larger files. We have noticed that saving a Word Document of 5MB takes around 10 seconds to save whereas an Excel (xlsx) file will take up to 90 seconds for a file of 500KB!

    Any ideas as to why SP Online "throttles" Excel files more than others?

    Laurence Lemmon-Warde

    • Edited by Laurence73 Tuesday, October 16, 2018 4:27 PM
    Tuesday, October 16, 2018 4:16 PM


  • Saving the document as a pdf and then renaming it speeds the process up but that is far from acceptable. We have also noticed that saving metadata against the excel file takes about 20 times longer than for any other file type.

    Laurence Lemmon-Warde

    • Marked as answer by Laurence73 Friday, March 29, 2019 5:37 PM
    Tuesday, October 16, 2018 5:47 PM