Microsoft Teams (ms-teams.exe) High CPU Usage Problem: Technical Analysis and Fix Guide

Quick Triage

• Quit and relaunch Teams: Right-click the Teams tray icon → Quit → start Teams again.
• Disable video effects for the current call: On the pre-join screen, set Background effects → None (or Blur).
• Restart the WebView2 container: Close Teams, wait 20–30 seconds until all msedgewebview2.exe processes disappear in Task Manager, then relaunch Teams.
• Reboot once if the spike followed a Windows or Teams update.

If CPU drops only briefly or spikes again at idle, proceed with the structured fixes below.

Prerequisites

• Windows 10/11 with local admin rights
• Stable internet (for update/repair steps)
• Access to Task Manager, Resource Monitor, and optionally Process Explorer
• Ability to temporarily adjust graphics settings and disable add-ins (if Outlook/Office is installed)

Background: How Teams Consumes CPU

Modern Teams uses a multi-process architecture:

• ms-teams.exe — primary app container and UI.
• msedgewebview2.exe — Edge WebView2 surfaces that render parts of the app (chat, meeting surfaces).
• Optional GPU and helper renderers for video encoding/decoding, screen capture, and effects.

CPU spikes are expected during meetings (encoding video, background effects, content sharing). Problematic behavior is defined by sustained high CPU at idle or excessive usage during routine actions (typing, switching chats) without video workloads. Root causes typically include corrupt cache, suboptimal GPU routing, heavy effects, add-in conflicts, or stalled WebView2 instances.

Common Causes of Teams High CPU

1. Corrupted Teams cache (loops, re-render storms).
2. Background effects (custom images, filters) taxing CPU/GPU.
3. GPU acceleration mismatch (driver issues; toggling helps).
4. Outdated/wedged WebView2 runtime processes.
5. Office/Outlook add-ins and overlays interacting with presence/meetings.
6. Hardware limits/thermal throttling on ultrabooks under load.
7. Org policies allowing expensive effects/bitrates on constrained devices.

Step-by-Step Guide to Diagnose and Fix High CPU Usage

1. Identify the Offender with Task Manager / Process Explorer

• Press Ctrl+Shift+Esc → Processes.
• Look for Microsoft Teams and any Microsoft Edge WebView2 children.
• Right-click Microsoft Teams → Go to details to confirm ms-teams.exe PID.
• In Process Explorer, hover the process to review child processes and CPU deltas.

If Teams/WebView2 holds >30–40% CPU for >5–10 minutes at idle, continue.

2. Update Teams (Prefer the “New Teams” Build)

• In Teams: Settings → About → Version (or profile menu → Check for updates).
• If you are still on “Classic” Teams, switch to the new client. The re-platformed build typically reduces memory and CPU usage during everyday work and meetings.

3. Clear the Teams Cache (Correct Path for Your Build)

Close Teams completely (tray icon → Quit). Then clear the cache:

Classic Teams (Electron)

%AppData%\Microsoft\Teams

Delete the contents of the folder (leave the folder itself), then relaunch Teams.

New Teams (Store/UWP)

%UserProfile%\AppData\Local\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams

Delete the contents, then relaunch Teams.

Tip: If in doubt which one you have, check Apps & features entry name and the on-disk path above.

4. Right-Size GPU Acceleration and Per-App Graphics

• Classic Teams: Settings → General → (Un)check Disable GPU hardware acceleration. Test both states; some GPUs lower CPU when acceleration is on, others behave better with it off. Restart Teams after changing.
• New Teams: Use Windows Settings → System → Display → Graphics → select Microsoft Teams → set High performance (dGPU) on laptops that have it. This offloads video work and often reduces CPU spikes.

5. Tame Video Effects and Bandwidth-Hungry Features

• Background effects: Use None or Blur instead of custom images/filters.
• Incoming video: Temporarily turn off incoming video when on battery or in hot environments.
• HD and frame rate: If offered, disable HD video and reduce frame rate in meeting options.

6. Refresh the Edge WebView2 Runtime

• Exit Teams; ensure all msedgewebview2.exe processes close (wait ~30 seconds).
• Launch Microsoft Edge → … → Help and feedback → About Microsoft Edge to trigger runtime updates.
• Optionally run the WebView2 installer/repair from Microsoft to re-register the runtime if it appears corrupted.

7. Neutralize Add-ins and Integrations (Test Mode)

• In Outlook → File → Options → Add-ins → Manage COM Add-ins → Go…, temporarily disable the Microsoft Teams Meeting Add-in and any third-party overlays (screen recorders, video filters).
• Close Outlook and Teams; relaunch Teams alone. If CPU is normalized, re-enable add-ins one by one.

8. Repair or Reinstall Teams Cleanly

• Settings → Apps → Installed apps → Microsoft Teams → Advanced options → Repair (if available).
• If issues persist: Uninstall, then reinstall the latest New Teams from Microsoft. This resets cache, policies, and WebView2 bindings.

9. Admin Controls (Organization-Wide Mitigations)

• Cap media bitrate in Meeting policies to reduce encoding pressure on endpoints.
• Restrict video effects (allow Off or Blur only) for low-power fleets.
• Preconfigure Windows Graphics per-app assignments (e.g., Teams → High performance on dGPU laptops).
• Standardize driver and WebView2 runtime versions via device management to eliminate variance.

10. Diagnostics and Evidence

• Resource Monitor (resmon.exe) → CPU → Processes: watch Teams/WebView2 CPU over 10–15 minutes at idle.
• Event Viewer (Application and Services Logs → Microsoft → Windows → AppModel-Runtime, AppxDeployment-Server) for WebView2/container issues.
• Teams logs (after a repro): press Ctrl+Alt+Shift+1 to collect; review under:

%UserProfile%\Downloads\MSTeams Diagnostics

(Folder name may vary by build; check the latest generated archive.)

Validation and Testing

• Idle baseline: With Teams signed in and no calls, CPU should settle to low single digits after a few minutes.
• Active call test: Join a meeting with camera off, then on, then enable Blur. CPU should spike briefly but stabilize.
• A/B checks: Compare CPU before/after cache clear, GPU toggle, and per-app graphics changes to identify the winning fix.
• Sustained stability: Let the system idle for 15–30 minutes with Teams open; there should be no prolonged CPU plateau.

Strengthening System Stability Going Forward

• Keep Teams and Edge/WebView2 on current versions.
• Avoid third-party “optimizer” tools that kill background services—they often cause re-index or sign-in storms later.
• Use modest background effects (prefer None/Blur) as the default.
• Standardize graphics drivers and power profiles on managed fleets.
• Apply meeting policy constraints for devices with known thermal/CPU limits.

Final Thoughts: Make Teams Boring Again

High CPU in Teams is usually not a mysterious “bug” but an interplay of cache state, rendering path, and video processing features. By resetting cache, aligning GPU usage with your hardware, minimizing effects, and keeping WebView2 healthy, you return the client to a predictable baseline where CPU spikes are brief and tied to real work (screen sharing, encoding), not idle churn.

For organizations, a small set of policy and driver standards prevents the issue from resurfacing at scale.

FAQ

%AppData%\Microsoft\Teams

%UserProfile%\AppData\Local\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams