Why is SharePoint So Slow? [SharePoint.com Slowness Today Explained]

Waiting for a SharePoint page to load can be frustrating. Many users ask, “Why is SharePoint so slow?” or search for answers about SharePoint.com slowness today. The truth is, why is SharePoint Online so slow depends on multiple factors, such as large libraries, poor connectivity, or Microsoft’s service health.

All these and other causes with fixes, we’ll discuss in this guide. So, let’s get started!

Table of Contents

• Why is SharePoint Slow Online & On-Premise? How to Fix
  • #1. Large Libraries & Lists
  • #2. Heavy Customisations & Web Parts
  • #3. Network Latency
  • #4. Browser & Local Issues
  • #5. Search Indexing Delays
  • #6. Microsoft Service Health Issues
  • #7. Inefficient File Syncing
  • #8. Admin Playbook
• Quick Fix Checklist
• Author’s Verdict
• People Also Ask

Why is SharePoint So Slow Online & On-Premise? How to Fix Step by Step

As I served as a SharePoint admin for over 15+ years, I clearly know the root causes behind sharepoint.com slowness today and how to troubleshoot in minutes, whether you are using On-premise or Online: 

#1. Large Libraries & Lists

Having lists/libraries with 100k+ items leads to load slowly. To resolve this:

• Split large libraries into smaller ones.
• Use indexed columns and filtered views.
• Enable content types to organise files logically.
• Backup SharePoint Online to local storage, and then delete unwanted items from the SharePoint lists/libraries.

So, if your SharePoint environment is cluttered with large lists, libraries, or unused sites, performance will always suffer. In such cases, migration to a cleaner tenant can resolve this quickly. 

For the same reason, the Professional SharePoint Online Migration Tool is the only option to move libraries and lists efficiently without losing metadata or hierarchy.

Manual methods like SPMT won’t support tenant to tenant migration. That’s why opting for an automated tool is necessary to resolve why is SharePoint so slow.

#2. Heavy Customisations & Web Parts

Overloaded pages with too many web parts or custom scripts increase the time for the page to load. So, 

• Remove unused or redundant web parts.
• Replace classic pages with modern pages, as they load faster.
• Optimise custom scripts by loading them asynchronously.

#3. Network Latency

Microsoft’s data centres are not available everywhere across the world. Users accessing data from regions far from Microsoft’s data centres experience the “SharePoint.com slowness today”. To fix:

• Run a latency test.
• Use Microsoft Edge servers or a VPN closer to the data center.
• Enable Content Delivery Network (CDN) in SharePoint Online for static content.

#4. Browser & Local Issues

Outdated browsers, heavy extensions, or cache conflicts many times affect the SharePoint speed, and users ask why is SharePoint so slow. For the same:

• Clear browser cache and cookies.
• Test in an incognito/private window
• Keep browsers updated, like Edge or Chrome.

#5. Search Indexing Delays

Newly added documents are not showing up, or the SharePoint Search not working, will be fixed by:

• Re-check search schema and managed properties.
• Wait for Microsoft’s indexing cycle.
• Use filters or metadata navigation for faster manual search.

#6. Microsoft Service Health Issues

A Microsoft 365 outage (global slowness). This takes time to resolve, as it is from the Microsoft side. Still, we can resolve SharePoint.com slowness today by:

• Check the Microsoft 365 Service Health Dashboard.
• Use third-party monitoring tools for confirmation.
• Inform users proactively that it’s a Microsoft-side issue.

#7. Inefficient File Syncing

Sync SharePoint document library to local folder or through OneDrive clogs up bandwidth sometimes, if not configured correctly, which is why is SharePoint so slow:

• Use OneDrive Files On-Demand instead of syncing everything.
• Access large libraries via the browser, not sync.

#8. Admin Playbook

Step 1. Find the largest site collections. Ensure the SharePoint Online Management Shell is installed or update SharePoint Online Management Shell. Now run these commands:

Connect-SPOService -Url https://mackjohn-admin.sharepoint.com

Use this to clean up large sites. Remember to run these cmdlets properly; otherwise, it can create Connect-SPOService: Could Not Connect to SharePoint Online, or no valid OAuth 2.0 authentication session exists error.

# List site storage usage

Get-SPOSite -Limit All | Select-Object Url, Owner, StorageUsageCurrent | Sort-Object -Property StorageUsageCurrent -Descending | Format-Table -AutoSize

Step 2. Fix the list performance

• Add indexed columns.
• Rebuild views to return fewer than 5,000 items.
• Move old/archived content to an archival library.

Step 3. Throttling mitigation

• Inspect automation schedules to resolve why is SharePoint so slow.
• Implement exponential backoff and obey Retry-After. Sample pseudo-logic:

retryCount = 0
while retryCount < maxRetries:
  call API
  if response == 429:
    wait = computeExponentialBackoff(retryCount) + jitter
    sleep(wait)
    retryCount += 1
  else:
    break

Follow Microsoft’s guidance on Graph and throttling best practices.

Why is SharePoint So Slow – Quick Fix Checklist

Whenever I hear “Why is SharePoint Online so slow?” I provide this quick checklist to that user:

1. Check the Microsoft Service Health Dashboard.
2. Test network latency and bandwidth.
3. Open the site in incognito mode.
4. Review large lists/libraries and split them if needed.
5. Remove heavy web parts from the landing page.
6. Switch from classic to modern experience.

Author’s Verdict

Why is SharePoint so slow? Why is SharePoint Online so slow? SharePoint.com slowness today? All these queries are almost the same, and I’ve explained all in detail, with the troubleshooting steps. 

So, now you know the reasons behind it and how to resolve without any external or IT help.