Activity, retention, and the review copy that outlives deletion

Gemini's controls are shaped differently from its competitors'. There is no single training toggle. There is an activity setting that governs history and training together, a default retention period measured in months, and a third rule for anything a human reviewer has looked at. The third one is the one worth your attention, because it is the only one deletion does not reach.

Gemini Apps Activity

Activity is kept for 18 months by default. You can change that to 3 months or 36 months, or switch auto-delete off so nothing expires on a schedule.

Turn the setting off and, in Google's wording, your future chats will not appear in your Activity and will not be used to train its AI models, unless you choose to send feedback. That last clause matters more than its length suggests. See below.

Even with the setting off, conversations are held with your account for 72 hours, which Google describes as necessary to respond to you and to protect the service. So "off" means "not retained as history and not used for training", not "nothing is stored".

The three-year copy

Google states that chats reviewed by human reviewers, along with related data such as your language, device type, location information or feedback, are not deleted when you delete your activity. They are retained for up to three years instead.

Chats are disconnected from your Google Account before they are sent to reviewers, so this is not a named archive of your conversations. It is still a copy that your deletion does not reach.

This also explains the feedback clause above. Sending feedback on a response is the one action that can route a conversation into review even when your activity setting is off. It is a small button with a longer consequence than its placement suggests.

Work and school accounts are a different product

Gemini through Google Workspace runs under the Cloud Data Processing Addendum rather than the consumer terms, and the difference is not cosmetic.

Google states that prompts are customer data, that Workspace does not use customer data to train models without the customer's prior permission or instruction, and that your content is not human reviewed or used for generative AI model training outside your domain without permission. Its summary of the boundary is that your interactions stay within your organisation.

Retention moves to your administrator and varies by surface. The Workspace documentation gives Gemini in Workspace a range from 90 days to indefinite under admin control, the Gemini app up to 36 months under admin control, and Gemini Notebook not retained once the session ends.

Try this

Open your Gemini Apps Activity settings and read two things: the auto-delete period currently set, and whether the activity setting is on. Then decide whether 18 months matches how you actually use it. For most personal use, 3 months is closer to the truth and costs almost nothing.

What goes wrong

Reading "off" as "nothing is kept". There is still a 72-hour window.

Assuming deleting activity deletes everything. Reviewed conversations are held up to three years and deletion does not reach them.

Sending feedback on a sensitive conversation. That is the action that can put it in front of a reviewer even when activity is off.

Mixing a personal account and a work account by whichever tab was open. They run under different terms, and only one of them carries the training and review commitments.

Setting auto-delete once and never revisiting. Google chose that default for the general case. Yours may well be different.

How to check it worked

Change the auto-delete period, then come back a day later and confirm the setting held rather than assuming the dialog saved. On a work or school account, ask your administrator which retention value is actually configured for your domain, because the admin setting overrides what you would choose and the range runs from 90 days to indefinite.