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Artificial intelligence · privacy

Information you should never give an AI

What ChatGPT, Gemini and Claude keep from your chats, for how long, and what you should never type into them.

Ibrahin · Published on 2 September 2026 · 2 min read

Text drafted with artificial intelligence. The topic, the angle and the final review are Ibrahin's. How AI is used here

A woman sorting cards of personal data into two piles: some marked with a shield and others with a padlock.
Illustration, not a real screenshot.

What has happened

The three most used AIs keep your conversations longer than it seems:

  • Claude (Anthropic): since September 2025 it asks whether you allow your chats to be used to improve its models. If you said yes, it keeps them for up to five years; if you said no, 30 days. This applies to Free, Pro and Max accounts.
  • Gemini (Google): even with history turned off, it keeps your conversations for 72 hours. Human reviewers also read a share of them, and those reviewed conversations are kept for up to three years, even if you delete your activity.
  • ChatGPT (OpenAI): temporary chats are not used for training, but OpenAI may keep a copy for up to 30 days for safety.

Why it matters to you

Whatever you paste into a chat leaves your phone or computer and stays on another company's servers. If you paste a contract, a payslip or a medical report, that data may be kept for months or years, and in some cases a person may read it. And if it is someone else's data —a client, a relative— it isn't yours to share.

What you can do

1. Never paste this

  • passwords, verification codes and recovery phrases;
  • card numbers, bank accounts, ID or passport numbers;
  • medical reports and diagnoses;
  • other people's data without their permission;
  • internal documents from your job.

2. Everything else, without names

Replace names, phone numbers, addresses, emails and exact amounts with “person A”, “company B” or “about €1,000”. Removing just the name isn't enough: company, job title and date together can point to someone. For almost everything, a made-up example works just as well.

3. Check your AI's setting (two minutes)

  • ChatGPT: Settings → Data controls → “Improve the model for everyone”. For one-off things, use a temporary chat.
  • Gemini: in your Google activity, the option to keep Gemini activity (“Keep activity”).
  • Claude: Settings → Privacy → the option to help improve Claude. You can change it at any time.

4. If you already pasted something sensitive

  • If it was a password or a code, change it now.
  • Delete the conversation, knowing a copy may remain for a few days.
  • If it was work data or someone else's, tell whoever is responsible.

The recommendation

Treat an AI chat like an email to a stranger: only write what you wouldn't mind another person reading.

Sources checked

Review

Responsible for publication: Ibrahin. Date: 2026-09-02. Last checked: 2026-10-13.