GSX Blog

Troubleshooting SharePoint Performance Issues with F12

Posted by Pavan Reddy on Tue, Sep 04, 2018

illuBlog-microscopeWhat do you do when users outside of the main office complain about SharePoint performance? Is it the application or the network that’s slowing them down?

SharePoint Online is a black box for users and the IT Teams. Whenever a user reports a slow SharePoint site, IT does not know where to look or how to troubleshoot the issues further. There are tools to help us analyze the SharePoint Online page performance issues and suggest best practices as Microsoft recommends. One of them is the F12 Developer tool.

Today I am going to show you how we can enable the F12 tool through Explorer and the parameters you need to look for. 

  1. We recommend using Internet Explorer to access the F12 developer tools


  1. Here we are navigating to
  2. Press F12,to load the page on browser 
  3. Now you will have to stop the profiling session.


  1. Before you stop the profiling session, make sure the page is completely loaded and you can identify that by finding ;this is due to a background process that allows Exchange to notify you when you receive new messages or notifications
  1. Now you can find page we were trying to load and analyze the headers


  1. Select the headers tab to look at the three response headers as shown below


  • SPIIS Latency: The amount of time that the request spent queued and waiting to be processed by IIS.

Ideally, it should be zero or very close to zero. Here we see the value of SPIisLatency is 0ms.

  • SPRequestDuration: This is the amount of time that it took to process the request on the server. 

This is the end-to-end processing time for the page. Healthy pages range from a couple hundred milliseconds to around a second depending on the content of the page. 

Here we see the value of, the SPRequestDuration is 232ms.  

  • SharePointHealthScore: This is the value, from zero to ten, that indicates how heavily loaded the SharePoint Server is at the time when the page was served. Here we see the value of SharePointHealthScore is 0. 

There is another important fourth parameter you find on F12 developer tools result page that is Total trip time.


  • Total trip time:  This value indicates for the page being loaded, and it represents the elapsed time from the point at which the page was requested until the time when the last byte of the page was delivered.  

Now we have values for four important header parameters, and we use these values to identify what causing page performance issues. 

The formula is the following: Total Trip time - (SP request duration + SPIIS latency) = Time lost  


  • High time lost: If there is high time lost, then there is a slowness between your computer and SharePoint It could be routing, a proxy or the internal network.
  • High SPIS latency: if it’s high then it represents an issue on the server sideand also suggests requests are backing up on server. 
  • High SP Request duration: Means page taking long time to process on server. It can be an issue from your Sharepointpage with lot of customizations, navigation style, web parts and not only an issue with SharePoint Online.

Every tool has its limitations, and we recently observed most of the pages in SharePoint not showing SPrequest duration and SPIISlatency. Microsoft is aware and has released another solution called “Page diagnostics for SharePoint Online” that we will explore in another blog.

Want more info about SharePoint Online Monitoring? Check out the podcast of our webinar “
SharePoint and OneDrive Monitoring Best Practices”.

At GSX Solutions we provide a unique way to constantly and accurately measure the end user experience of SharePoint Online from where your users are.

Our Robot Users continuously use SharePoint Online exactly as a user would while checking the performance of the network. With that data, you can get back visibility on everything that matters to assess and improve the SharePoint user experience.


Tags: User Experience, Service Delivery, SharePoint Monitoring, APM, SharePoint Performance, Office 365 monitoring, End user Experience, office 365 performance, f12