Summary
- Microsoft is retiring Similarity Checker from Microsoft Word, removing it from the Microsoft Editor experience.
- The change affects organizations and users who currently rely on Similarity Checker for similarity, plagiarism, or originality checks in Word.
- Microsoft Editor will still provide spelling, grammar, clarity, and style suggestions, and other Word writing/editing/citation features are not changing.
- Microsoft 365 Copilot in Word is not affected, but it is not a formal similarity or plagiarism validation tool.
- No action is required, but Microsoft recommends reviewing any workflows, communications, and documentation that depend on Similarity Checker.
Microsoft Word’s Similarity Checker will be retired on October 3, 2026, and removed from Microsoft Editor. Other writing and editing features, including Microsoft 365 Copilot, remain unaffected. Organizations should review workflows, inform users, and consider alternatives if needed. No action or compliance issues are required.
Microsoft 365 Message Center ID: MC1466753
Primary Service: Word
Admin Impact: Low
User Impact: Medium
Release Start: 03 Oct 2026
Release End: 03 Oct 2026
Last Modified: September 4, 2026
Category: Plan for change
Tags: New feature, User impact, Admin impact, Major change
Status: Launched
Products & Platforms: Microsoft 365 apps
History
Updated September 10, 2026: We have updated the timeline. Thank you for your patience.
9/4/2026 Item Added to Message Center
Microsoft Message
We are retiring Similarity Checker in Microsoft Word on October 3, 2026. After the retirement date, Similarity Checker will no longer be available as part of the Microsoft Editor experience in Word.
This change allows us to focus on experiences and capabilities that are more broadly used across Microsoft Word.
Rollout schedule
Worldwide, GCC, and DoD: Beginning early October 2027
Impact on your organization
Who is affected
Organizations and users that currently use Similarity Checker in Microsoft Word
Platforms and services
- Microsoft Word
- Microsoft Editor
What will happen
- Similarity Checker will be removed from Microsoft Word.
- After retirement, users will no longer be able to access Similarity Checker through the Editor experience in Word.
- Other Microsoft Word writing, editing, and citation capabilities will not be affected.
- Microsoft Editor will continue to provide spelling, grammar, clarity, and style suggestions.
- Microsoft 365 Copilot capabilities in Word are not affected by this change.
Note: Copilot is not intended to serve as a formal similarity, plagiarism, or originality validation tool.
Action required and recommendations
No action is required.
If your organization currently uses Similarity Checker:
- Review workflows that depend on Similarity Checker.
- Inform users who rely on the feature about the upcoming retirement.
- Evaluate alternative solutions if formal similarity or originality validation is required.
- Update internal documentation or training materials that reference Similarity Checker.
Compliance considerations
No compliance considerations identified. Review as appropriate for your organization.