Grammarly
Grammarly says individual-account Product Improvement and Training is on by default, while enterprise and certain sales-led accounts have it off by default.
For individual Free, Premium, and single-user Pro accounts, Grammarly says content may be used for product improvement and model training unless the user turns the control off.
Use the Product Improvement and Training control in Grammarly privacy or data settings. Enterprise-tier accounts are stated off by default.
The cited support article distinguishes individual, multi-user, enterprise, and education accounts.
The support article explains training controls more clearly than a single retention answer.
The cited support article focuses on product improvement and training controls rather than human-review disclosure.
Foundational reference pages for teams adopting, deploying, and operating production AI with inspectable controls.