Word similarity checker: Microsoft moved the retirement to October 3, 2027

The Word similarity checker is due to retire on October 3, 2027, according to Microsoft's retirement notice, which was updated on September 10 with a new timeline. Articles written days earlier still say October 3, 2026. If you rely on the tool for submissions or reviews, you have a year to choose a replacement.

This post covers what changed, who has to act, and what to use for a formal check. Everything reflects the pages we read on October 25, 2026. Microsoft revises these notices, so confirm the date on the live Message Center entry before you build a plan around it.

Word similarity checker retirement: the date is October 3, 2027

Microsoft's Message Center notice MC1466753 was published on September 3, 2026 and last updated on September 10, 2026. Its text reads: "We are retiring Similarity Checker in Microsoft Word on October 3, 2027." The rollout line says "Beginning early October 2027" for Worldwide, GCC and DoD tenants. The notice also says "Updated September 10, 2026: We have updated the timeline."

Coverage written before that update used the earlier year. A TechRepublic article dated September 7, 2026 says the feature "is scheduled to disappear on October 3, 2026." We read a Wayback copy of that article and it carries no correction. Search results we saw on October 25 also showed headlines naming October 3, 2026, so a reader who stops at the first result may think the tool is already dead.

One more claim is worth a flag. A blog post on the WPS Office site, dated October 7, 2026, says Microsoft "temporarily withdrew" the feature because it "was not functioning correctly" and will restore it. WPS sells a competing office suite, and the claim does not match the notice above. We could not test a live Word install, so we cannot say what your copy shows today.

Who has to act now, and who does not

Microsoft's notice says "No action is required," and then lists steps for organizations that use the feature. Our reading of who falls where:

• Students and writers who run a quick check before submitting: you still have the tool as far as the notice goes. Start choosing a replacement this academic year rather than in September 2027.
• Schools, publishers and review teams with Word in their process: this is the group the notice addresses. It recommends that you review workflows that depend on the checker, tell affected users, update training material and "evaluate alternative solutions if formal similarity or originality validation is required."
• IT admins: the notice lists no required admin action and no compliance considerations, so the work is communication and documentation.
• People who never open the Similarity pane: nothing changes. The notice says Microsoft Editor keeps its "spelling, grammar, clarity, and style suggestions," and other writing, editing and citation features are not affected.

How to tell whether your copy still has it

Microsoft's support page for the feature lists the steps, and it applies to Word for Microsoft 365 and Word for Microsoft 365 for Mac. As of October 25, 2026 that page carries no retirement notice.

1. On the Home tab, select Editor.
2. In the Editor pane, scroll down to Similarity and select Check for similarity.
3. When the check finishes, select Similarities reviewed, then insert a citation or select Ignore for each match.

If the Similarity section is missing in your copy today, the notice we read does not explain why. Check the Message Center entry and your tenant's update channel before you assume the feature has been retired early.

What the checker did, and what it never promised

Microsoft describes the tool this way: it "highlights what's unique in your document and makes it easier to add citations." It reports what share of your text matches content it found online and how many passages need review, with a link to each original.

TechRepublic makes the point that matters for any replacement: the percentage and the passage count "were not a declaration of plagiarism," because a quotation, a cited passage or a common phrase can all match. A person still has to read each flag.

Microsoft's notice adds one line that settles a common question. Microsoft 365 Copilot in Word is unaffected, but "Copilot is not intended to serve as a formal similarity, plagiarism, or originality validation tool." If you were planning to ask Copilot to do the job, the vendor itself says not to.

What to use for a formal similarity check

Replacements differ mostly in who is allowed to buy them and how much text the free tier covers. The table uses each vendor's own pages, read on October 25, 2026.

A few notes on the rows. Grammarly's plans page lists "Detect plagiarism and AI generated text" under its paid Plus plan and marks plagiarism checking unavailable on Free; the prices it showed us were in rupees, so we left them out. The sources quote is from its plagiarism checker page. Quetext's pricing page shows US dollars, and its free plan covers a plagiarism check of up to 1,000 words. Turnitin's help article, which we read in a Wayback copy dated July 31, 2026 of the page it marks as updated June 3, 2026, says the company "does not sell individual licenses or single-use subscriptions" and sells exclusively "at the institutional level."

In our view the deciding question is who will read the result. If a school or journal has its own checker, use that one, because it is the report they will see. If you only want to catch accidental overlap before you submit, a paid Grammarly plan or Quetext's free tier is a reasonable first pass. If you need to run a long thesis, check the word caps before you pay, because the free Quetext plan stops at 1,000 words.

None of these tools proves originality. Each vendor describes its own set of sources, and the sets differ. Treat a clean result as "no match found in that vendor's sources" and follow your school or publisher's own rules on what counts as plagiarism.

What to do before October 2027

Upfynd lists 189 tools in Writing & Publishing and 121 in AI Writing, as of October 25, 2026, and Turnitin sits in Learning & Development. If you maintain a review process that leans on Word, write down which step the Similarity pane covers today, pick a replacement by the end of this academic year, and set a reminder to reread MC1466753 in the spring. Dates in these notices have already moved once.

Our post on Microsoft Whiteboard alternatives covers another Microsoft retirement, on October 16, where the question was the same: who actually has to move, and by when.