How to Fix Outlook Typing Lag and High CPU Usage in Office 365

For months, users of Microsoft's classic Outlook app within Office 365 have reported significant typing lag, often accompanied by high CPU usage. This issue, which caused frustration among many, has been acknowledged and addressed by Microsoft.

User Reports and Initial Observations​

Users began noticing that while composing emails, Outlook would exhibit a noticeable delay in registering keystrokes. This lag was often accompanied by CPU spikes ranging from 30% to 50%, leading to increased power consumption and reduced system performance. Discussions on platforms like Reddit and the Microsoft Community forums highlighted the widespread nature of this problem.

Microsoft's Acknowledgment and Response​

In early April 2025, Microsoft published a support page titled "CPU spikes when typing in classic Outlook for Windows," acknowledging the issue. The company detailed that users might observe significant CPU usage when composing emails, especially if the Task Manager was open during typing sessions. Microsoft assured users that a fix was in development and provided an estimated timeline for its release across different Office channels:

• Beta Channel (Version 2505 Build 18822.15000): Early May 2025
• Current Channel Preview (Version 2505 18827.20000): Mid May 2025
• Current Channel (Version 2505 18827.20000): Late May 2025

For users on the Semi-Annual Channel, Microsoft identified the issue and suggested a workaround involving reverting to an earlier version of the software. However, they cautioned against this due to potential security vulnerabilities associated with older versions.

Community-Driven Solutions and Workarounds​

Before Microsoft's official acknowledgment, the user community actively sought solutions to mitigate the typing lag and high CPU usage. Several workarounds emerged:

• Disabling Hardware Graphics Acceleration: Some users found that turning off hardware graphics acceleration within Outlook settings reduced the lag.
• Managing Add-ins: Disabling unnecessary or malfunctioning add-ins helped alleviate performance issues for certain users.
• Adjusting Power Settings: Modifying Windows power settings to prevent CPU core parking showed improvements in some cases.

While these solutions provided temporary relief, they were not universally effective and often required technical expertise to implement.

Microsoft's Official Fix and Recommendations​

With the rollout of the updates in May 2025, Microsoft addressed the root cause of the typing lag and high CPU usage in Outlook. Users are advised to ensure their Office 365 applications are updated to the latest versions to benefit from these fixes. For those who continue to experience issues, Microsoft recommends:

• Checking for Updates: Regularly updating Office applications to incorporate the latest performance improvements and security patches.
• Monitoring Add-ins: Reviewing and managing installed add-ins to ensure they are up-to-date and compatible with the current version of Outlook.
• System Maintenance: Performing regular system maintenance, such as clearing cache and ensuring sufficient system resources, to maintain optimal performance.

Conclusion​

The typing lag and high CPU usage in Microsoft's classic Outlook app were significant concerns for Office 365 users. Microsoft's acknowledgment and subsequent release of targeted updates demonstrate the company's commitment to addressing user-reported issues. By staying informed about software updates and following recommended practices, users can ensure a smoother and more efficient experience with Outlook.

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Source: Inkl The Outlook typing lag wasn’t your imagination — Microsoft just explained why