Word Similarity Checker Missing or Not Working? Here’s Why

The date distinction above follows Microsoft’s retirement notice, reproduced publicly. Last verified: September 12, 2026. Last updated: September 12, 2026. The checks below help narrow the problem; they are not tested repair guarantees.

For the retirement timeline and what remains available, see Microsoft Word Similarity Checker retirement: updated timeline.

First: Check the Date

Before the early October 2027 rollout: continue with the symptom that matches your screen. The future retirement notice alone does not explain a failure now.
During or after the early October 2027 rollout (retirement date: October 3, 2027): if the entry is missing, check the retirement branch before attempting repairs. The revised rollout window begins early October 2027; the retirement date does not establish exact removal timing for your account. Notice.

If Similarity Checker Is Completely Missing

First check the documented location: Home → Editor, then scroll down to Similarity. Microsoft’s instructions place Check for similarity inside that section. Official instructions.

If it is absent there, distinguish an availability problem from a check that runs and fails:

Note the signed-in account and whether you are using desktop Word or Word for the web.
Check connected-experience controls, including any work or school restrictions.
Before retirement, compare the other client using the same account.

Still missing before retirement? If both clients lack the entry, or you cannot test another client, classify this as availability unconfirmed. Ask Microsoft support or your administrator to check your account and feature access; do not keep repeating scan or installation repairs. If policy controls are disabled or locked, use the settings branch below.

Confirmed historical example: Microsoft hid the web button during its 2024 incident. That shows a missing entry can be service-related; it does not establish why yours is missing today. The incident is marked fixed. Microsoft incident record.

If You See “Something Went Wrong”

The message alone does not identify the cause. Microsoft confirmed a 2024 incident affecting every desktop build, alongside the missing web button. A service change fixed that incident by March 25, 2024. It is historical evidence, not confirmation of a current outage. Official incident record.

Diagnostic checks — not confirmed fixes:

Record the exact message and when it appears.
Try a new document with non-sensitive sample text to see whether the failure is limited to one file.
Compare desktop and web with the same account and sample, where available.
Check the documented privacy controls below. If the failure persists across both clients, use the stop-and-escalate branch.

If only the original document fails: record the difference and seek document-specific support; the test does not identify corruption or another root cause. If no second client is available: record that comparison as not tested and escalate with the evidence you have. You do not need to buy another Word plan to complete this diagnostic step.

It starts, then asks you to try again

User-reported; cause unknown: a February 2026 Microsoft Q&A report describes a check that begins processing but does not complete. Record this as a failed check, not a missing feature. That report does not establish a universal fix.

A percentage appears, but you cannot review matches

Microsoft describes completed results as a percentage plus passages that you can open through Similarities reviewed. Expected behavior.

If you can open the results, learn how to interpret the percentage and review each match.

User-reported; cause unknown: this community thread describes percentages and match counts without usable passage review. If that matches your screen, report the broken review step specifically. Do not treat the visible percentage as evidence that you have reviewed the matching sources.

If It Works Differently in Word Desktop and Word for the Web

Compare the same account and document. Changing both at once makes the result harder to interpret. These are diagnostic signals, not root-cause findings:

One client works: use it to finish reviewing sources if appropriate. Record which client fails; this does not prove the desktop installation is damaged.
Both clients fail: account, policy or service behavior remain possible. Use the stop-and-escalate branch instead of repeating the same repairs without new evidence.
One client has no entry: if the other works, use that working route if appropriate. If the other errors, report missing in one client, failing in the other to support or your administrator. This result does not resolve account eligibility or prove an outage; do not repeat the same cross-client test.

Confirmed documentation, with a limitation: Microsoft’s feature comparison lists Editor with Similarity Checker for desktop and web. Its US usage page lists Microsoft 365 Word and Mac in “Applies To,” but omits web. These pages do not establish availability for every account. The old 2024 disablement notice is not evidence that web support is permanently gone before retirement.

Account, Feature Availability and Settings Factors

Confirmed mechanism: Microsoft lists Similarity Checker as a connected experience and as an optional experience that relies on Bing. Disabling connected experiences can make affected commands unavailable, grayed out or return errors. Connected experiences, optional experiences.

Windows desktop Word: open File → Account → Account Privacy → Manage Settings and inspect connected experiences. Microsoft documents this route for personal accounts and Microsoft 365 Apps for enterprise. Privacy controls.
Mac desktop Word: open Word → Preferences → Privacy to inspect the available privacy options. Mac instructions.
Work or school account: if the dialog says your administrator has disabled optional connected experiences, that confirms a policy restriction on those experiences. Ask the administrator whether access can be allowed; local reinstalls do not change that policy. Admin-controlled availability.

Choose the outcome: if the relevant control is off and you can manage it, decide whether you want that connected experience enabled, then retry once if you enable it. If it is locked, absent, or unclear, report policy status unconfirmed to your administrator or support. If it is enabled and the check still fails, continue to the cross-client or escalation branch. An enabled control does not confirm account eligibility. These documented desktop paths are not verified instructions for Word for the web.

Protected organizational documents: ask your administrator whether the content-analysis or encryption restrictions documented by Microsoft apply to the file. Enterprise restrictions.

Unknown: the evidence does not establish a complete 2026 plan-by-plan eligibility table. Do not assume every paid Microsoft 365 account has the feature, or that buying another plan will restore it.

What Microsoft’s October 3, 2027 Retirement Changes

Confirmed announcement, accessed through a public reproduction: Microsoft updated MC1466753 on September 10, 2026, postponing the originally announced October 3, 2026 retirement to October 3, 2027. Rollout is now scheduled to begin early October 2027 and will remove Similarity Checker from Word’s Editor. Other Word editing and citation features remain; Microsoft does not describe Copilot as a formal similarity validator. Announcement.

Once removal has reached your environment, stop trying to restore the checker through local repairs. We have not verified a universal removal time. Administrators can check the original Message Center notice; our research did not access a signed-in tenant.

When Troubleshooting Is No Longer Worth It

Our decision rule: stop repeating local repairs when the same account fails in desktop and web, a new sample document also fails, and connected experiences are confirmed allowed. This is an escalation threshold, not proof of a Microsoft outage. If a client or privacy check is unavailable, include that limitation in the support request rather than treating it as a passed check. For work or school accounts, contact your administrator; personal-account users can contact Microsoft support. Ask them to investigate the access or service state that these tests leave unresolved.

A July 2026 Tech Community report describes continued failure after updates, repairs, a new document, network changes and tests in both clients. User-reported; root cause unverified. It provides a reason not to promise that reinstalling Office will solve this symptom.

Before retirement, give Microsoft support or your administrator the error text, time, Word version, account type, privacy-control status and cross-client results. Ask your administrator to check service health. We have not confirmed an active September 2026 incident or a restoration time.

If a deadline arrives before the issue is resolved—or retirement has removed the feature—move to another checking workflow.

What to Use Instead

If you need another way to check matching text and review sources, continue to Microsoft Word Similarity Checker Alternatives. That guide covers access requirements, workflows and limitations so you can choose your next step.

Evidence and Limits

Confirmed labels identify Microsoft documentation or the reproduced announcement. Diagnostic possibility means a check may narrow the issue, not establish its cause. User-reported examples establish reported symptoms only; we did not reproduce them or count comments as independent incidents.

The diagnostic branches retain our September 7, 2026 evidence review. On September 12, 2026, we reverified the updated retirement notice and Microsoft’s current Home → Editor → Similarity instructions; we did not rerun the other diagnostic research. We have not tested repairs in a signed-in Word account. Current outage status, exact account eligibility, the cause of broken passage review, and per-account removal timing remain unknown. Recheck the announcement and opening answer before the early October 2027 rollout and on October 3, 2027 before relying on this page for post-retirement diagnosis.