Microsoft Word Similarity Checker Retirement Delayed to October 3, 2027

Already having trouble? Troubleshoot a missing or failing Similarity Checker.

Was the retirement delayed? The announcement and update timeline

The updated serv365 archive records both the original publication date and the September 10 modification. The September 10 reproduction at Modern Workspace Pro matches the revised date and rollout window.

Why you may still see October 3, 2026

That was the originally announced date. Material based on the September 3 announcement may preserve the previous timeline; Microsoft subsequently updated it on September 10. When comparing dates, check which revision of MC1466753 the source describes. The current schedule is October 3, 2027, with rollout beginning early October 2027.

What changes — and what stays

Changes / removed	Still available
Similarity Checker access inside Editor	Editor, including spelling, grammar, clarity and style suggestions
The integrated online-match scan and review workflow	Word’s other writing and editing capabilities
Citation insertion through Similarity Checker’s matched passages	Word’s separate citation and bibliography tools
Similarity Checker itself	Microsoft 365 Copilot in Word; it is not a formal substitute for similarity validation

The retirement notice establishes these boundaries. Microsoft’s notice, publicly reproduced.

What you lose in practice: Microsoft’s current instructions place the checker under Home → Editor → Similarity. A scan returns an online matching-text percentage and passages to inspect; users can follow source links, insert a citation or ignore a match. Removing the feature removes that integrated route from finding a match to handling its attribution. Current workflow.

What citations still mean: the separate Word workflow uses References, Insert Citation, Manage Sources and Bibliography. It lets you record and cite sources; it does not replace scanning your text for online matches. The linked documentation specifies its supported Word versions rather than promising identical menus in every client. Word citation documentation.

Does everything disappear on October 3, 2027?

Microsoft gives October 3, 2027 as the retirement date and separately describes rollout as beginning early October 2027. The checked notice does not provide a precise per-account cutoff schedule. Do not treat the date as a promise that every account or client loses access simultaneously. Rollout schedule.

Unknown: the exact Windows, Mac and web removal times, whether a client update is involved, and what happens to historical scan state or unreviewed source links. The notice does not establish deletion of existing citations or historical results.

Why is Microsoft retiring it?

Microsoft says it is directing attention toward Word capabilities used more broadly. The checked notice supplies no usage figures, maintenance costs or detailed internal decision. It does not identify Copilot as the cause of retirement. Stated reason.

What should you plan before October 3, 2027?

The postponed schedule gives you time to evaluate requirements; the announcement does not require an immediate migration. Choose by the task you actually need to finish:

• Only spelling or grammar: you do not need a replacement because of this retirement; those Editor functions are unaffected.
• Online similarity scanning: evaluate another checking workflow ahead of the 2027 retirement if your work depends on this feature. Decide whether you need matched passages, source links or a submission report.
• Mainly citations: check whether Word’s separate reference tools already meet your need. You may need to replace source discovery, rather than citation formatting.
• A school or institution requires a plagiarism report: confirm which service and report it accepts. Do not assume Word’s online-match workflow meets that requirement.

These are task-based recommendations. Microsoft requires no action to implement the retirement, while advising dependent organizations to review workflows, inform users and update guidance. Preparation advice.

Is Similarity Checker already missing?

As of September 12, 2026, the announced start date is still ahead. Microsoft’s current help page still describes Home → Editor → Similarity. A missing button or failed scan now cannot be attributed to the October 3, 2027 retirement from this notice alone. Current Microsoft instructions. Troubleshoot a missing or failing Similarity Checker.

Need a replacement?

If you depend on similarity scanning, compare Microsoft Word Similarity Checker alternatives by access requirements and the checking workflow you need.

Evidence and verification limits

Last verified: September 12, 2026. Last updated: September 12, 2026. We rechecked the September 10 revision in the serv365 archive and Modern Workspace Pro reproduction, plus Microsoft’s current similarity instructions. The separate citation workflow retains its September 9 documentation review. The original Microsoft 365 Message Center notice requires eligible signed-in access; we did not access a tenant copy. The archives reproduce the same announcement, so they are corroborating copies, not two independent Microsoft announcements.

The Copilot limitation above comes from that reproduced notice. Documentation review does not confirm removal timing for your account or test the feature in a signed-in Word session.