DeepSeek can be a reasonable choice for everyday questions, learning and drafting with non-sensitive information. Keep confidential work and sensitive personal data out of its online chat, and check important answers before acting on them. The main decision is what you are willing and permitted to send to an online service.
This guide focuses on DeepSeek’s official website and app. A different website offering a DeepSeek model has its own operator and data practices.
Start with what you plan to share
Asking for a spreadsheet formula using made-up rows is different from uploading a customer database. Asking for a polite payment reminder is different from pasting an invoice with bank details and a client’s address. You can often get the help you need by describing the task and leaving the real records out.
Keep passwords, API keys, identity documents, medical records and confidential business material out of the prompt. Replacing a person’s name is not enough if the remaining details identify them. For work files, use the service your employer has approved for that kind of information; a personal account does not give you permission to upload company data.
Also separate privacy from accuracy. An answer can expose no private information and still be wrong. Check sources and calculations, and review generated code before running it. For decisions about health, money or legal rights, involve a qualified professional rather than treating a chat response as advice.
What happens to your prompts?
DeepSeek’s privacy policy, updated February 10, 2026, says it may collect prompts, chat history and uploads, alongside account, device and network information. It also describes using personal data to improve services and train its technology. A conversation with the official service should not be treated as a private file stored only on your device.
The policy says DeepSeek directly collects, processes and stores personal data in China. If your work has restrictions on where data can go, check those before uploading. Using a VPN does not turn the hosted service into local processing.
There can also be other recipients: the policy says search features share input keywords with third-party APIs. Leave confidential names and project details out of search requests as well as ordinary prompts.
Control training, sharing and deletion separately
Model improvement: DeepSeek’s Terms of Use, updated March 27, 2026, name a control called “Improve the model for everyone.” Turn it off if you do not want your dialogue data used for improvement. If the control is unavailable to you, the privacy policy lists privacy@deepseek.com for privacy requests. Opting out is separate from deleting data: the policy allows retention for service, security and legal purposes and does not give one fixed retention period for everything.
Shared conversations: anyone with a share link can view the linked dialogue, according to the terms. Read the whole conversation before sharing it, including your own messages and any details repeated in the answer. Avoid posting links that expose information you meant to keep private.
Delete a chat: in the web history, open the … menu beside the conversation and choose Delete. In the app, long-press the conversation and select Delete. DeepSeek’s help instructions warn that deleted chats cannot be recovered.
To leave the service entirely, its account-deletion instructions give the path Settings → Account settings → Delete Account. Save anything you need first: deletion removes the account’s chat history and forfeits any unused developer-account balance. Account deletion is not a promise that every retained record disappears immediately; the terms allow legally required data to be kept.
What do the security reports actually show?
There have been documented problems. On January 29, 2025, Wiz reported an exposed DeepSeek database containing chat-history material and other sensitive information. Wiz said DeepSeek secured it after being notified. That was a real exposure, but the report does not show an ongoing breach.
In February 2025, NowSecure reported flaws in the iOS app it examined, including unencrypted transmission of some device information. South Korea’s privacy regulator later documented specific changes, including a stop to sending user input to Volcano Engine in April 2025. Those changes do not establish that every reported issue was fixed.
These dated findings justify caution with sensitive data. They do not verify the security of the current app. Getting the app from the official store helps avoid an impersonator, but it does not remove the provider’s privacy risks. Use the official download links and keep the app updated.
Does using an API or a local model change the answer?
The official API still sends requests to DeepSeek’s hosted service. It is not local processing, and paying for API access is not by itself a promise of zero retention. For confidential work, confirm the applicable API terms and data controls before connecting the service to your files.
A downloaded DeepSeek model running entirely offline can keep prompts on your computer. For example, LM Studio documents offline chat with downloaded models. That benefit depends on the setup: connected tools, cloud services or shared access to the computer can introduce other exposure. Our local requirements guide explains what hardware can run a suitable model.
For third-party apps and websites, check the operator’s policy rather than assuming DeepSeek’s controls apply. Chat-Deep.ai is an independent site; its service is covered by its own privacy policy. The model name alone does not tell you who receives or keeps your conversation.