Before sharing a private diary with an AI writing model
If you want help turning diary entries into a summary, reflection, or polished passage, first decide what information the model actually needs. Check the service’s current data and retention settings, remove identifying or highly sensitive details, and share only a short excerpt that serves your task. A “private” chat setting may change how conversations are saved or used, but you should read what the provider says it does before relying on it.
Decide what you want the model to do
A clear, limited request makes it easier to share less. For example, you might ask for a concise summary of a passage, help organizing events into a timeline, or a rewrite that preserves your tone. Each task needs different context: a rewrite may need the passage’s wording, while a timeline may only need dates and event descriptions.
Before pasting anything, write the request without the diary text. Identify the details the model needs to complete it, then consider whether you can omit or generalize everything else. If you want help with a difficult conversation, for example, you might replace names with “my friend” and leave out the person’s workplace, address, or other identifying details.
Check the service’s data controls and privacy terms
Look for the provider’s current explanation of whether conversations may be used to improve its services, who may review them, how long chats are retained, and what controls apply to deletion or temporary chats. These are separate questions: turning off one setting may not turn off all processing or immediately erase every copy.
Read the controls for the specific account and product you plan to use. Settings may differ across consumer and business offerings, and providers can update their terms and interfaces. Avoid assuming that “temporary,” “private,” or “history off” means no data is retained or accessed for any purpose.
For a concrete example of why the details matter, Google’s [Gemini Apps Privacy Hub](https://support.google.com/gemini/answer/13594961?hl=en) says that some conversations may be reviewed by people to improve services. It also describes a 72-hour retention period for chats when Keep Activity is off, and explains that those chats may still be used to respond and protect Google and its users. Those statements apply to the described Gemini settings; they should not be generalized to other providers or products. Check the current policy for the tool you use.
If a control or policy is unclear, treat that uncertainty as a reason to share less. You can also choose not to use an AI service for material you would be uncomfortable having processed under the terms you can verify.
Identify details that could expose you or someone else
A diary can contain more identifying information than a name. A combination of a date, workplace, school, neighborhood, family relationship, or unusual event may make a person recognizable. Entries may also include intimate details about other people who did not choose to share them with a service.
Review the passage for details in these categories before submitting it:
Remove a detail if it is unnecessary to the task. Replace names with consistent labels such as “Person A” and “Person B.” Broaden a date to “last spring” or a location to “a nearby town” if the exact version is not needed. Keep enough context for the request to make sense, but avoid treating anonymization as a guarantee: combinations of remaining facts may still identify someone.
Share an excerpt instead of the whole diary
Select only the passage that relates to your request. If the entry is long, you can first create a shorter version yourself, leaving out background details the model does not need. For instance, a request to improve the clarity of one paragraph usually does not require a month of surrounding entries.
Use a prompt that states boundaries, too: “Summarize this excerpt in three neutral bullet points. Do not infer motives or add facts.” A narrow instruction cannot control a provider’s data practices, but it can help keep the model’s response focused on the task.
If you need to preserve your own record, keep the original in the diary app or file you already use. Do not rely on an AI conversation as your only copy; chat history, export, and deletion features vary by service and setting.
Make a decision with a short checklist
Before sharing, ask:
A useful rule of thumb is to share the least revealing version that still lets the model do the job. If the entry is deeply personal, identifies someone else, or contains details you cannot comfortably share under the provider’s stated practices, you can ask for general writing guidance without submitting the entry itself.