How to auto-delete old AI chat history
Set AI chats to delete by age or by count, save the conversations that matter first, see what auto-delete leaves behind and check that the rule works.
To auto-delete old AI chat history, open your assistant’s history or activity settings and choose a rule: remove chats after a set time, or keep only a set number of recent ones. Save the conversations you still need first, because removed chats don’t come back.
This guide covers saving what matters, picking a rule, what auto-delete leaves behind and how to check it works. Mono by Reunified is the main example and Gemini the second, but the steps fit any assistant with a history setting. Deleting a whole account isn’t covered.
1. Decide what your chat history is for
Most chats are useful for a day or less. A few hold reference material you return to. Auto-delete suits the first kind. Move the useful part of the second somewhere more lasting.
| Chat type | Useful for | Where the useful part should live |
|---|---|---|
| Quick question | Minutes | Nowhere, or a private chat |
| Draft built from client text | Until you send it | The final document in your files |
| Reference, such as a glossary | Months | A Markdown export or a note |
| A preference you keep repeating | As long as it’s true | A memory |
In a made-up example, Ana, a freelance translator, uses AI chat daily for client snippets. She wants nothing older than two weeks kept, but one chat holds a glossary she reuses.
2. Keep the few conversations you need first
Do this before you turn the rule on.
- Export it. In Mono, open the chat, choose Export conversation from the “+” menu and save the Markdown file. The export guide explains what the file includes.
- Turn preferences into memories. A memory shapes future chats and stays when the thread goes. In Mono, open Settings > Memories and choose Add. The memory guide covers keeping it accurate.
- Move facts into notes. Names and agreed wording are easier to find there than in an old thread.
Ana exports her glossary chat to her notes folder and adds one memory: “For client K, leave product names untranslated.”
3. Choose a rule by age or by count
An age rule removes chats after a set time. Mono counts that time from a thread’s last message, so a chat you keep using stays. A count rule keeps only your most recently used threads, so one busy day can remove chats from earlier in the week. Age suits a stated limit, such as “nothing older than two weeks”. Count suits a list that never grows past a set size.
In Mono, open Settings and choose History in the Security section. By age offers 1, 3, 7, 14, 28 or 90 days. By count keeps 10, 30, 100, 200 or 500 threads. Until you change it, Mono keeps only your 100 most recent threads. It applies your choice when you leave the page, and again while the app runs.
By default, Gemini auto-deletes activity older than 18 months. On the web, under Settings & help > Activity, you can choose 3, 18 or 36 months, or turn auto-delete off. For another assistant, search its help pages for “auto-delete”. If it has no timer, set a monthly calendar reminder and delete by hand.
Ana chooses By age, 14 days.
4. Know what auto-delete doesn’t touch
A history rule removes chat threads. Check the rest separately:
- Memories stay until you edit or forget them.
- Files such as exports, downloads and notes stay where you saved them.
- Other services keep what a tool did there, such as a sent email.
- Provider records follow the provider’s rules. Gemini’s privacy hub says temporary chats, and chats with Keep Activity off, stay with your account for 72 hours. Chats that human reviewers read are kept for up to three years, even if you delete your activity.
In Mono, the rule also removes threads from your linked devices.
5. Use a private chat for one-off questions
For questions that shouldn’t reach your history at all, many assistants offer a private chat. Gemini calls it a temporary chat.
In Mono, type /secret followed by your question to open Secret Mode. Secret Mode chats are never saved and never add memories. Ana uses it for one contract clause she doesn’t want stored.
A private chat changes what the app keeps. The model still reads the message, so it isn’t anonymous or offline, and the provider’s rules still apply.
6. Check the rule after a week
Run through this list:
- Open History. With an age rule, no thread should have gone longer than your limit without a new message.
- Mono’s list shows the date each thread started, not its last message. A thread started three weeks ago and used yesterday stays.
- Open the file you exported and find the memory you saved.
- Clear anything else by hand. Select… lets you pick several threads, and Delete all removes every one. Both are permanent.
In Ana’s list, every thread has a message from the last 14 days, and the glossary is still in her notes. Check your rule again when your work changes.
To see where your data goes beyond History, read the privacy and sync guide. Mono isn’t available yet, but you can join the waitlist.
