How Do I Troubleshoot Slow Upload Speeds?

This article contains some basic troubleshooting steps you can take if your files are taking a long time to upload. It also outlines potential causes of slow upload speeds.

Note: Old Box Experience

This page refers to the old Box experience. In Box, hover over a single file or folder with your mouse. If the item looks like the following image, you are in the right place.


Files and folders should look like this when you hover over them.Files and folders should look like this when you hover over them.

If the item does not look like the image above, visit the link below instead:


Troubleshooting Steps:

  1. How Can I Check my Network Connection to Box? If upload speeds continue to be slow, there may be a problem with your Internet service connection. Please reach out to your Internet Service Provider and complete the speed tests below to verify your connection is working properly:


  1. Problems with the drag-and-drop upload of folders. We recommend trying the following:
    • Go to Account Settings and click the Content & Sharing tab along the top. Select/deselect the Enable Box Accelerator option under Uploading Content. Click Save.
    • We recommend leaving the Enable Box Accelerator option checked since slowness is usually a temporary network condition that will clear itself.
    • Try uploading with Firefox or Chrome. They provide enhanced capabilities over Internet Explorer, resolves most Java issues, and will provide the best Box experience.
    • Restart your computer. Occasionally, one-time issues may prevent Java from functioning correctly, and a restart may solve these problems. Make sure to Allow the Drag and Drop applet once you restart and attempt the upload again.
    • Check your version of Java and update to the latest release of Java.
    • Box Accelerator is a global data transfer network that improves the speed of your uploads. If you are having issues with uploads try turning this off temporarily:


Enable Accelerator Image



Potential Causes

Slow upload speeds can have a variety of causes. Box does not limit, throttle, cap, or even shape  upload speeds. These speeds are determined primarily by the user’s connection and computer.

If you find that your upload is taking longer than it should, we have listed a few reasons that may affect upload speeds.


  1. Firewalls: Firewalls can slow down or block the upload process. If you use third-party software, try temporarily turning off firewalls such as ZoneAlarm, the built-in Windows or Mac firewall, or any others.
  1. Business network restrictions: Users accessing Box from an office setting may find that their IT department has blocked or slowed down connections to Box.
    • Try consulting your IT department on restrictions they may have placed on uploads or unapproved web sites.
    • You can determine this by leaving your company network (ex. try a coffeeshop with WiFi) and seeing if the issue persists.
    • VPNs may cause your IP address to be misplaced and inadvertently place your computer in another geographic location other than your actual location. This can affect your upload speeds. Ask your network / IT department if a VPN could be changing your actual location on the internet.
  1. Choosing an Upload Method: If you are having an issue uploading, we suggest you try another one of the 3 methods. When you click on the Upload button in your Box account, you should see two links in the pop-up window: Upload Files and Upload Folders.

How can I optimize my upload speeds? - 2

  • If you click on the Upload Files feature you will use our HTML5 (or Flash-based) upload tool, which we recommend for fewer, smaller files.
  • We recommend Upload Folders, a Java-based upload tool, for larger files, folders or a larger number of files. Note: Chrome works with Upload Folders but does not need Java.


  1. Browser Specific Issues: Try a different browser or computer. Users may find that their upload speeds increase on alternative browsers.
  1. Device Specific Issues: If your upload speed has not improved after you have tried updating and/or switching internet browsers, please try a different computer to help isolate the issue.
    • If your upload speed increases on another computer, then you will know that the first computer itself was causing the slower speed.
    • If your speed does not increase, then this is most likely an issue with your internet connection.
  1. Internet Service Provider: Sometimes slow upload speeds are the fault of your Internet Service Provider.
    • We recommend a high speed internet connection with high upload speeds.
    • Often with Cable and DSL, the upload speed is significantly slower than the download speed. This will result in fast loading times for most websites and file downloads, but slow uploads.


A Note on Kilobytes vs. Kilobits

There is a difference between “Kb” (kilobit) and “KB” (kilobyte). One kilobyte is equal to eight kilobits. Internet service providers (ISP) often calculate and advertise upload and download speeds in terms of “Kbps” (kilobits per second) while Box uploads are calculated in terms of “KBps” (kilobytes per second). Therefore, if you are receiving upload speeds of 30 KBps this would be interpreted as 240 Kbps by your ISP.



Bandwidth and the Box Accelerator: 

Upload speed depends on your network connection and a component of this is bandwidth.

  • Bandwidth allowance determines the amount of data that can pass from the Internet to your web browser in a given amount of time.
  • A smaller bandwidth results in a longer time that it takes Internet data to transfer on your web browser. 

For business and enterprise accounts, Box has proprietary accelerator nodes that allow us to route your uploads through the fastest network route. To kick-start this feature, we suggest uploading approximately 9 files (between 2 and 6MB each) to your account, to initialize the accelerator node’s search for the best route. From there on out, your connection will route your uploads through the fastest route to Box. It takes only a handful of uploads per week to keep the Box Accelerator optimally tuned for your whole office.

Version history
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Last update:
‎01-24-2018 09:00 AM
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