Temporary chat, history off and delete are three different things

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Three controls sound similar but do different jobs: a temporary or incognito conversation, a history setting that is turned off, and deleting a chat outright. Someone trying to keep a sensitive conversation out of long-term storage needs to know which one actually does that, and for how long a copy can still exist afterward.

What the documents say

OpenAI's Temporary Chat FAQ, as retrieved on 16 September 2026, states that a temporary conversation 'won't appear in your history unless you choose to save it' and 'won't be used to train our models while it remains temporary,' but adds that 'for safety purposes we may still keep a copy for up to 30 days.' Google's activity help page states that Gemini Apps activity is kept when Keep Activity is on, and that 'by default, your Gemini Apps activity older than 18 months is auto-deleted,' with the period adjustable to 3 or 36 months. Anthropic's retention page states that deleting a Claude conversation removes it from chat history immediately and from back-end storage within 30 days, that chats used for model improvement can be retained in de-identified form for up to five years, and that inputs and outputs flagged for a Usage Policy violation can be kept for up to two years. Each vendor separates ordinary retention from a longer, safety-related retention window.

Check this

The mechanism worth testing is what a control leaves untouched. A temporary or incognito chat is designed to skip history and training, not to guarantee instant, unconditional deletion; OpenAI's own FAQ describes a 30-day safety copy. Turning off history-style settings, such as Google's Keep Activity, stops future storage but does not, by itself, delete what was already retained under a separate schedule such as auto-delete. Deleting a conversation is the strongest of the three, yet Anthropic's page shows even a deletion has a short back-end tail, and content already inside a training run does not get pulled out retroactively. Compare the exact verb each page uses, such as appear, keep, delete and retain, rather than assuming they are synonyms.

What holds and what fails

The pattern holds well as a guide to intent: a temporary mode is for not building a record in the first place, a history toggle is for not accumulating one going forward, and deletion is for removing what already exists. It fails as an assumption of immediacy: every vendor here documents some retained copy, whether for safety review, fraud prevention or an in-progress training run, that outlasts the visible action a person just took. That gap is stated plainly in each document; it is not evidence of concealment.

• Use a temporary or incognito mode before typing something sensitive, not after.
• Check your product's auto-delete period and shorten it if the default is longer than you want.
• Do not treat 'deleted' as synonymous with gone everywhere immediately.

None of these controls is a promise that a sentence disappears the moment a button is pressed. Reading the retention window named in the document is what tells a person how long a residual copy can realistically exist.