The short answer
If you only use one of them, its own memory is probably all you need, and it costs nothing extra. The differences are in what each one draws on, how much you can see and change, and how they treat sensitive details. Everything below is from OpenAI's and Anthropic's own help pages as they read on 13 October 2026; both say features vary by plan, so yours may differ a little.
How ChatGPT remembers
ChatGPT's memory can draw on several sources: your past chats, saved memories, your custom instructions, files in your Library, and connected apps such as Gmail, depending on your plan and region (OpenAI's help page). You find the controls under Settings, Personalization, Memory, where you can see a memory summary and correct it. When ChatGPT uses something it remembers, a Sources list can appear under the reply.
A few details worth knowing. Deleting a chat doesn't delete a saved memory that came from it; you remove both. If you turn off "Reference chat history", what it learned from past chats is scheduled for deletion within 30 days. And on personal accounts, OpenAI may use chats and remembered information to improve its models while "Improve the model for everyone" is on, which you can turn off in Data controls.
How Claude remembers
Claude's memory is on by default for Free, Pro and Max on the web, Claude Desktop and the mobile apps. On Team and Enterprise plans the owner decides, and each member turns it on for themselves (Anthropic's help page).
Claude saves memory as topics while you chat, and you can read, edit or delete each one under Settings, Memory. Every project has its own separate memory. Searching your past chats needs a paid plan. By default it doesn't keep sensitive subjects such as health, religion or politics unless you choose to include them, and some things, like government ID numbers and financial account numbers, it never saves.
Side by side
| ChatGPT | Claude | |
|---|---|---|
| Cost | Included; features vary by plan | Included on Free, Pro and Max; owner's choice on Team and Enterprise |
| What it draws on | Past chats, saved memories, custom instructions, Library files, connected apps | Topics saved from your chats; past chats by search on paid plans |
| Seeing and changing it | Memory summary you can correct, Sources under replies | A list of topics you can read, edit and delete |
| Projects | Project-only memory in some business workspaces | Each project has its own memory |
| Sensitive details | Can appear if you share them | Left out by default unless you opt in |
| Where it's kept | Your OpenAI account | Your Anthropic account |
| Shared with the other | No | No |
As of 13 October 2026, from each company's own help page, and may change. Check the links above for the latest.
If you use both
This is where the built-in memories run out. Each one lives in its own company's account, so a preference you gave ChatGPT last month means nothing to Claude today. Claude can import from ChatGPT once, which helps if you're moving for good, but anything you tell ChatGPT afterwards stays there.
The other way is a memory that sits outside both and that both apps connect to. Zaaheen, which we make, is one: it keeps your memories encrypted on your own computer, and Claude Desktop and the ChatGPT app for your computer save to it and read from it.
We tested this. Five AI apps on one Windows computer, ChatGPT and Claude Desktop among them, shared one Zaaheen memory, and we asked eight questions about the person, mostly in a different app from the one that saved the answer.
| Option | Questions |
|---|---|
| Answered by itself | 4 of 8 |
| Once told to check | 3 of 8 |
| Blocked by an add-on | 1 of 8 |
Source: Zaaheen's own live test, 26 September 2026, Windows, with Claude Desktop, Cursor, ChatGPT (Work and Codex) and Antigravity. The blocked answer was a Google add-on crashing Antigravity's tool calls before they reached Zaaheen.
Half the time the app checked the shared memory by itself; otherwise it answered from its own memory first. Adding this line to each app's instructions fixes most of that: "When I ask you to remember something, save it in Zaaheen. Before answering anything about me, my preferences, my work or my plans, also check my Zaaheen memory, even when your own memory has nothing."
Two limits to be fair about. ChatGPT reaches Zaaheen only through the ChatGPT app for your computer, not in a web browser or on your phone. And Zaaheen runs on Windows and Macs with Apple chips, with no phone version. If you use one app, stay with its own memory; if you use both every week, a shared one saves you repeating yourself.
ChatGPT and Claude are names of their owners, OpenAI and Anthropic. We have no link with either. If anything here is wrong or out of date, tell us at customerservice@zaaheen.com and we'll correct it.