An AI that keeps its memory on your phone

Why it matters where an AI's memory lives

Memory is the most personal thing an assistant has. It's a running list of your plans, the people you know, your job applications and your preferences, built up from your conversations. If that list lives on a company's servers, it is covered by that company's retention rules, security and legal obligations. If it lives on your phone, it stays on your phone unless you back it up or share it.

How ChatGPT's memory works

OpenAI's help page describes two kinds of memory (OpenAI Help: Memory in ChatGPT, checked Nov 8, 2026):

• Saved memories: details you ask ChatGPT to remember, or that it saves itself. They are "stored separately from chat history", and "deleting the original chat does not automatically delete a separate saved memory."
• Reference chat history: ChatGPT can draw on past conversations. Turning this off schedules that information for deletion from OpenAI systems within 30 days.

You can view, correct and delete memories in Settings → Personalization → Memory. OpenAI notes it "may retain logs of deleted saved memories for up to 30 days for safety and debugging purposes." If you want a conversation that leaves no memory behind, Temporary Chat "does not create or update memories while the chat remains temporary" (OpenAI Help: Temporary chat).

ChatGPT's memory works well, syncs across your devices, and runs on far more capable models than any phone can. The trade-off is that the memory is kept on OpenAI's side, not yours.

How Sema's on-device memory works

Sema is built around keeping memory on the phone:

• As you chat, Sema saves lasting facts, such as a job you applied for, a person you met or a preference, in the app's storage on your iPhone.
• The Memories view lists everything saved, along with the sentence it came from. You can delete one memory, or clear all data in Settings.
• Answers come from Apple's on-device model where Apple Intelligence is available, or from an optional on-device Gemma 3 1B download on other iPhones. Your chats and memories aren't sent to us.
• There is no account, so there is no server copy to subpoena, leak or restore. That also means there is no sync between devices, and deleted data can't be recovered.

What can leave the phone: anonymous usage analytics (never chat or memory text), and, only if you allow web search, a cleaned-up search question sent through Sema's server to Brave Search. Details are in the Sema privacy policy.

Other options

• Lumo by Proton has a Memory feature that "retains context and preferences across sessions". Proton says conversations are stored with zero-access encryption that even Proton can't read. It's a cloud service, so your messages are processed on Proton's servers (App Store, proton.me/lumo).
• Duck.ai saves your recent chats locally on your device by default, with optional encrypted Sync & Backup. Its privacy policy describes chat storage, not a memory feature (Duck.ai privacy policy).
• Private LLM lets you write your own system prompt. That isn't automatic memory, but you can put the standing facts you want it to know there, and everything stays on the device (App Store).