You hand your phone to a friend so they can look at a photo. They swipe back, the chat list opens, and there is the conversation where you described your medical test results. ChatGPT now lets you put a lock on that one conversation and leave everything else exactly as it was.
What OpenAI actually added
On Tuesday, OpenAI added a feature called locked chats to ChatGPT, the assistant app that answers questions in ordinary language. You choose one saved conversation and put it behind a four-digit PIN. On a phone you can use your face, your fingerprint or your normal screen unlock instead of typing the numbers.
A locked chat disappears from your normal chat list, from the chats you pinned to the top, and from search inside the app. It moves to its own small area, reached by tapping Projects and then Locked chats. The rest of the app behaves as before.
What the lock does, and what it does not do
Think of a locked drawer inside a house. The drawer has its own key. The house still has windows, and the person who owns the house can open that drawer whenever they like.
OpenAI states the limits plainly. A locked chat is not encrypted end to end, meaning it does not become a message that only you and one other person can read. Locking does not change how long OpenAI keeps the conversation. It does not change the setting that allows your chats to be used for improving the model. And it does not erase anything ChatGPT already remembered about you before you locked the chat.
The lock solves a smaller and more ordinary problem: other people using your screen.
Why this matters to you
People tell chatbots things they would not tell a stranger. A symptom that worries them, a debt they are ashamed of, a message they are afraid to send, a surprise they are planning for someone in the family. That makes the chat app one of the most personal things on a phone.
And phones travel. A child in the back seat, a colleague at your desk, a repair shop, a screen shared during a video call, a laptop left open in a shared flat. Each of those is a moment when your chat list is visible and nobody meant it to be.
How to lock a chat, step by step
- Open the conversation you want to hide.
- Tap the three-dot menu at the top of that chat.
- Choose Lock chat, then Lock chat again to confirm.
- The first time, ChatGPT asks you to create a PIN: four digits, typed twice.
- To open it later, tap Projects, then Locked chats, then enter the PIN or use your face or fingerprint.
- When you are done, tap Lock now so the titles hide again. On a phone, access also ends by itself after about a minute away from the screen.
The one mistake that erases everything
If you forget the PIN, ChatGPT offers a reset. That reset deletes every locked chat, every file inside them, and anything remembered only there. It cannot be undone, and OpenAI support cannot recover it for you.
So write the four digits down somewhere outside the app, or switch on face or fingerprint unlock and keep a written copy at home. After too many wrong attempts the app makes you wait before trying again. Wait it out rather than resetting.
Common misunderstandings
Myth: a locked chat is private from OpenAI too
No. It hides a conversation from the people using your device. OpenAI can still read it, keep it for as long as its rules allow, and use it under the same model-improvement setting as any other chat.
Myth: locking a chat makes ChatGPT forget what you told it
No. Whatever it learned before the lock stays in your normal memory. Locked chats keep their own separate memory from then on, so new details do not leak back into your ordinary chats.
Myth: my employer can unlock it for me
On a work account, an administrator cannot open your locked chats or reset your PIN. But on Business, Enterprise and Edu accounts, locked chats still appear in the company’s compliance records. The lock protects you from the person holding your phone, not from your employer.
What to watch for next
The feature is arriving gradually. If the three-dot menu offers no Lock chat, it has not reached your account yet. Some conversations cannot be locked at all: temporary chats, archived chats, group chats, chats made from a shared link, and chats with scheduled tasks or meeting recordings.
Two habits go with it. A device where the app is already open can keep showing a chat title until it refreshes, so look at your other screens before you share one. And on Android, a screenshot of a locked chat comes out blank or black. Treat that as a courtesy, not a guarantee.
The one thing to remember
A lock protects a conversation from the next person who picks up your phone. It does not take back what you already typed, and it does not shut OpenAI out. Use it for the chats you would not want read over your shoulder, and keep the PIN somewhere that is not inside the app.
Image: “Samsung Galaxy S24, Sperrbildschirm” by C.Stadler/Bwag, Wikimedia Commons, licence CC BY-SA 4.0 (creativecommons.org/licenses/by-sa/4.0).