Microsoft Removing Word Similarity Checker and Changing Text

Microsoft will discontinue the Similarity Checker in Word on October 3, 2026, forcing students, educators, and organizations to find alternative tools for source-matching and originality verification [2]. The move comes alongside a broader shift in how Microsoft handles AI-driven writing assistance, including moving Text Predictions to an opt-in feature across Word and Outlook [2].

Changes to writing and review tools

The Similarity Checker, which has been part of Word for six years, serves as a checkpoint for users to identify passages that match online content [2]. While the tool provides a similarity percentage and highlights potential matches, Microsoft has long maintained that these results are not a definitive declaration of plagiarism, as they include properly cited quotes and common phrases [2]. Following the October 3, 2026, retirement, users will no longer have access to this integrated source-matching capability, requiring institutions to adopt third-party services or revise their internal review processes [2].

Simultaneously, Microsoft is altering the behavior of Text Predictions, the feature that anticipates user input in Word and Outlook [2]. Unlike the Similarity Checker, this feature is not being removed, but it will transition to an opt-in model [2]. Users who prefer to have the software suggest upcoming words or phrases will need to manually enable the feature in their settings as the update rolls out [2]. Microsoft has not provided a specific timeline for the rollout, noting that further details will be communicated through Microsoft 365 administration channels [2].

Broader shifts in AI access

These updates follow a period of significant restructuring for Microsoft’s AI-integrated office tools. Earlier this year, on April 15, 2026, the company removed Copilot Chat from Word, Excel, PowerPoint, and OneNote for business users lacking a paid Microsoft 365 Copilot license [4]. For large organizations with more than 2,000 seats, the removal was absolute, while smaller firms saw their access downgraded to a throttled "Standard Access" tier [4].

The distinction between these tools remains a point of emphasis for the company. Microsoft has explicitly warned users that Copilot should not be treated as a replacement for formal plagiarism or originality checks, even as it continues to refine its AI-assisted writing suite [2]. While Copilot remains available for Outlook and via standalone web interfaces, the removal of the Similarity Checker marks a narrowing of the native, automated compliance tools available directly within the Word application [2, 4].

What to watch

• October 3, 2026: The official retirement date for the Similarity Checker, after which the feature will be removed from all Word versions [2].
• Microsoft 365 Administration Channels: The primary source for updates regarding the rollout schedule for the opt-in Text Predictions change [2].
• Institutional Workflow Adjustments: Monitoring how academic and editorial organizations transition to third-party plagiarism detection services following the loss of the native Word tool [2].

The retirement of the Similarity Checker leaves a gap in integrated academic workflows that Microsoft has not yet signaled it intends to fill. Whether the company introduces a more specialized, paid-tier replacement or leaves the market entirely to third-party developers remains the primary open question for institutional users.