DeepSeek suits developers and tinkerers who want a free assistant plus an API that plugs into coding tools. ChatGPT suits business owners who want web search, file uploads, image creation and data controls in one free account. If you handle client data, check where DeepSeek stores it before you paste anything in.
Both assistants answer questions, draft copy and reason through problems, so the gap isn't raw cleverness. It's everything around the chat box: the tools you get, the limits you hit, and what happens to the words you type. I read both companies' own pages for this comparison and kept only what they say themselves.
DeepSeek and ChatGPT side by side
| DeepSeek | ChatGPT | |
|---|---|---|
| The product | DeepSeek's official AI assistant (app and web chat) plus a developer API | OpenAI's AI assistant on the web and mobile apps |
| Free to use | Yes, the official app is listed as free | Yes, there's a Free tier |
| Modes on the free version | DeepThink and Search | Think (mobile app, rolling out on the web) and web search |
| Files, images and data | Not described on the pages I read | Upload images and files, analyse data, create images (each with its own limit) |
| Everyday chat limit | Not stated | Unlimited everyday text chats, subject to abuse safeguards |
| Build your own assistant | Not mentioned on the pages I read | New GPT creation isn't available on personal accounts, Free included |
| Developer access | API in an OpenAI and Anthropic compatible format | Not covered by the Free tier FAQ |
| Where your data goes | Stored in the People's Republic of China, per its privacy policy | You can stop new chats training OpenAI models in Data controls |
| Ads | None mentioned | May appear in the Free tier in certain countries |
What the DeepSeek app gives you
DeepSeek's home page shows two switches on top of a normal chat, DeepThink and Search. The App Store listing calls it DeepSeek's official assistant and lists it as free. Where it stands out is the developer side.
- The API speaks the same format as the OpenAI and Anthropic APIs, so existing code and tools can point at it with a changed base address.
- DeepSeek's own docs say it can run as the model behind Claude Code, GitHub Copilot and OpenCode.
- It names its current models in the docs, so a developer knows which one they're calling.
What ChatGPT's Free tier includes
OpenAI's Free tier FAQ is unusually specific. Free users get unlimited everyday text chats, web search, file and image uploads, data analysis, image creation and access to existing GPTs, plus a Library with 500 MB of storage. Uploads, images, voice and data analysis each have their own limit, and ChatGPT tells you when you hit one.
- You can use GPTs other people have built, but you can't create new ones on a personal account.
- Hitting a limit pauses that tool until it resets; the reset time shows in the app.
- Ads may appear on the Free tier in some countries.
Where your conversations end up
This is the part most comparisons skip. DeepSeek's privacy policy says it will "store your Personal Data in People's Republic of China", and that it uses what people share to train and improve its models. That's a straight statement, not a scare story, and it matters if you paste in client briefs, contracts or customer emails.
ChatGPT gives you a switch instead. The OpenAI Help Center explains that turning off Improve the model for everyone (Settings, then Data controls) stops your new conversations being used to train OpenAI models, while they still sit in your chat history. If you've already compared ChatGPT and Gemini on real marketing work, this setting is worth checking whichever assistant you settle on.
Which one fits which kind of business
Pick DeepSeek if you're a developer, a technical founder or someone who likes testing models through an API, and the work you send it isn't sensitive. Its compatibility with existing tools makes it easy to try without rewriting anything.
Pick ChatGPT if you run a small business and want one account that can search, read your files, make images and keep a library, with a clear switch for training. It's the easier fit for client-facing work. For other options by task, see my list of AI tools for small business.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
My advice before you choose
Decide what you'll paste in before you decide which assistant to use. Public research, social captions and brainstorming are fine almost anywhere. Anything with a client's name on it belongs in a tool whose data rules you've read and switched to the setting you want.
Do you make an AI assistant or chatbot? Tool makers can ask to be considered for a featured place in comparisons like this one.
Frequently asked questions
Is DeepSeek free to use?
The official DeepSeek app is listed as free on the App Store, and the web chat offers DeepThink and Search modes. Developers use the API separately.
Is ChatGPT free?
Yes. OpenAI's Free tier FAQ says ChatGPT is free to use, with unlimited everyday text chats subject to abuse safeguards and separate limits on uploads, images, voice and data analysis.
Where does DeepSeek store my data?
Its privacy policy says it collects, processes and stores personal data in the People's Republic of China, and it may use what you share to train its models.
Can I stop ChatGPT training on my chats?
Yes. Turn off Improve the model for everyone under Settings, then Data controls. New conversations won't be used to train OpenAI models.
