The short answer
ChatGPT, from OpenAI, is the better choice for most work: it wins writing, coding, research, files and privacy, and its Business and Enterprise plans keep your data out of training by default. DeepSeek, from Hangzhou DeepSeek Artificial Intelligence Co., Ltd., wins on price and open weights: DeepSeek-V4-Pro is free in Expert Mode and downloadable under the MIT licence. But DeepSeek's app stores your data in China, so use it only for public material.
| ChatGPT | DeepSeek | |
|---|---|---|
| Made by | OpenAI, United States | Hangzhou DeepSeek Artificial Intelligence Co., Ltd., China |
| Free plan model | GPT-6 Luna in the Chat tab | DeepSeek-V4.1-Flash-1017, plus DeepSeek-V4-Pro in Expert Mode |
| Top models | GPT-6 Sol in Chat; GPT-6.1 Sol and Terra in Work and Codex (Plus and up) | DeepSeek-V4-Pro |
| Paid plans | Go, Plus, Pro, Business, Enterprise | None for the chat; pay-as-you-go API |
| Context | 27K tokens on Free (about 12 pages), more on paid plans | Up to 1 million tokens |
| Files and data analysis | Yes: spreadsheets, documents, decks, audio on paid plans | Reads images on Flash; no documented data analysis tool |
| Coding | Codex agent; GitHub on Business | Free chat help; API works with Codex and Claude Code |
| Where data is stored | OpenAI, a US company; EU data residency for new Enterprise and Edu workspaces | People's Republic of China, under PRC law |
| Training on your chats | On by default for Free, Go, Plus, Pro; off for Business and Enterprise | May be used after de-identification unless you switch it off |
| Open weights | gpt-oss models (2025), not the GPT-6 models in ChatGPT | DeepSeek-V4-Pro under the MIT licence |
ChatGPT vs DeepSeek: the verdict
For work, pick ChatGPT. OpenAI's assistant wins writing, coding, research, files and privacy for anyone using the app, because it has the deeper toolset and work plans that keep your data out of training by default. Pick DeepSeek for two things only: free access to a strong reasoning model on material that is already public, and open weights your company can run on its own servers. If you remember one line, make it this: DeepSeek's app stores everything you type in China, so it is a learning tool, not a place for client work.
The two products are not built the same way. ChatGPT is a paid product with a generous free tier: Free and Go run GPT-6 Luna in the Chat tab, while Plus, Pro, Business and Enterprise have run GPT-6 Sol there since 7 October 2026. The newest GPT-6.1 Sol (29 September) and GPT-6.1 Terra (from 26 October) live in ChatGPT Work and Codex on Plus and higher plans. DeepSeek, made by Hangzhou DeepSeek Artificial Intelligence Co., Ltd., is free on the web and in its apps. Since 17 October 2026 it uses DeepSeek-V4.1-Flash-1017 by default, and Expert Mode switches to DeepSeek-V4-Pro. DeepSeek earns money from its developer API, not from chat subscriptions.
Writing: ChatGPT wins
ChatGPT is the better writing partner for work. Paid plans get GPT-6 Sol in the chat, plus projects, memory and the larger context that lets you keep a brief, a style guide and a draft in one place. Answers can now include interactive pieces such as charts, buttons and small tools (OpenAI calls this Intelligent UI), which helps when a draft needs a comparison or a checklist alongside it. ChatGPT Slides, for eligible Pro, Business and Enterprise users, turns a draft into a deck you can export to PowerPoint, PDF or Google Slides.
DeepSeek writes competently and is often brief; DeepSeek itself says the October Flash update gives shorter outputs. That is fine for a quick paragraph, but most real writing at work involves names, numbers and plans you would not want stored on servers in China. The privacy gap decides this one as much as quality does.
Coding: ChatGPT wins for working developers, DeepSeek is the budget pick
ChatGPT wins because of Codex. It is OpenAI's coding agent, it runs the newest GPT-6.1 Sol and GPT-6.1 Terra models on Plus and higher plans, and ChatGPT Business connects to GitHub. For a team shipping code, that is a complete tool rather than a chat window.
DeepSeek is the best free option for code help in a browser. With Expert Mode on, DeepSeek-V4-Pro handles scripts, formulas and error messages well, and DeepSeek pitched its August V4-Pro release at agent work, with one-click setup for Codex. For developers, DeepSeek's API speaks both the OpenAI and Anthropic formats and works with tools such as Codex and Claude Code, and off-peak API calls have been half price since 16 August 2026. If you are building something and paying per token, DeepSeek is worth a test. Just remember that code you send to the DeepSeek API or app goes to DeepSeek.
Research: ChatGPT wins
ChatGPT has deep research on every plan, with higher limits on paid plans, and web search in the chat. DeepSeek has web search too, powered since October 2026 by its own in-house search engine, but DeepSeek does not document how the chat shows its sources. For research you need to check, that matters. If citations are the whole point, neither is our first choice: read the best AI for research and look at Perplexity.
Files and data: ChatGPT wins clearly
ChatGPT is built to work on files. It analyses spreadsheets, creates documents and decks in ChatGPT Work, has extensions for Excel, Word, PowerPoint and Google Sheets, and paid plans can transcribe and summarise uploaded audio. DeepSeek's strength here is narrower: its models accept up to 1 million tokens of context, so you can paste a very long public document and ask questions across all of it, and the default Flash model reads images. DeepSeek does not document a data analysis tool that runs calculations on your spreadsheet, so for numbers you would be relying on the model's arithmetic.
One caveat in DeepSeek's favour: ChatGPT Free has a small context window of 27K tokens, which OpenAI estimates at about 12 pages of input. A free user with a 60-page public report will get further in DeepSeek.
Privacy and data location: ChatGPT wins for the app, DeepSeek only when self-hosted
This is the biggest difference between the two, so here are the facts from each company's own pages.
- DeepSeek. Its privacy policy (updated 10 February 2026) says it collects, processes and stores personal data in the People's Republic of China, and its Terms of Use (updated 27 March 2026) are governed by mainland Chinese law. Inputs and outputs may be used, after de-identification, to improve the service unless you turn off Improve the model for everyone; DeepSeek does not publish the exact menu path, and you can also email privacy@deepseek.com. There is no business plan with admin controls. On 19 October 2026 the US Department of Homeland Security made public an order telling federal civilian agencies to remove DeepSeek technology from their systems. It does not apply to private companies.
- ChatGPT. OpenAI is a US company. On Free, Go, Plus and Pro, training is on by default, and you switch it off in Settings > Data controls > Improve the model for everyone. Temporary chats are not used for training. Business, Enterprise and Edu content is not used for training by default, with admin controls and SAML SSO on Business.
So for anyone using the app, ChatGPT wins: it has a work plan and DeepSeek does not. The twist is that DeepSeek's open weights can give you the most private setup of all, because a model running on your own infrastructure sends nothing to anyone. That is a job for an IT team, not a reason to use the app.
Price and value: DeepSeek wins
DeepSeek gives away its bigger model. Expert Mode puts DeepSeek-V4-Pro in front of free users, and DeepSeek publishes no paid consumer plan at all. ChatGPT Free is generous in its own way (unlimited text chats with GPT-6 Luna, within abuse guardrails, plus limited uploads, images, voice and deep research), but the bigger GPT-6 Sol, larger context and the newest GPT-6.1 models need a paid plan. Compare current prices on ChatGPT's pricing page. If your budget is zero and your material is public, DeepSeek gives you more model for nothing.
Open weights and self-hosting: DeepSeek wins
DeepSeek publishes the DeepSeek-V4-Pro weights on Hugging Face under the MIT licence, which allows commercial use. It is a 1.6-trillion-parameter model with 49 billion parameters active per token, so it needs serious hardware; the smaller Flash weights are cheaper to host. OpenAI does publish open-weight models, gpt-oss-120b and gpt-oss-20b, last updated on Hugging Face in August 2025, but these are not the GPT-6 models that run ChatGPT. If self-hosting a frontier-class model is the requirement, DeepSeek is the answer.
Same task, both tools
These walk-throughs are based on each tool's documented features, not on our own test runs.
Summarise a 60-page public industry report
ChatGPT: upload the PDF and ask for a one-page brief. On Free, the 27K-token window (about 12 pages) means the model cannot hold the whole report at once, so split it into sections or use a paid plan. On a paid plan, put it in a project so follow-up questions keep the context. DeepSeek: paste the full text; the 1-million-token context holds it comfortably. Because the report is public, the China storage question does not arise. Edge: DeepSeek for free users, ChatGPT for paid users who want to keep working on it.
Find the trend in a sales spreadsheet
ChatGPT: upload the file and ask for a chart and the three biggest changes; data analysis runs the calculations rather than guessing them. DeepSeek: you would paste the data as text and rely on the model's own arithmetic, and the figures would be stored in China. Edge: ChatGPT, comfortably.
Draft a reply to an unhappy client
ChatGPT: on Business or Enterprise, paste the thread; it is not used for training by default. On a personal plan, switch training off first or use a temporary chat. DeepSeek: only after removing every name and detail, and even then we would not. Edge: ChatGPT.
Who should pick ChatGPT, and who should pick DeepSeek
Pick ChatGPT if you use AI for real work with real data, you need files, spreadsheets, decks or coding agents, or your company wants admin controls and a contract that excludes training. It is the safer default for most professionals. Our guide to using ChatGPT covers which plan suits whom.
Pick DeepSeek if you are a student, hobbyist or professional working on public material, you want strong reasoning and code help without paying, or you are a developer looking for a low-cost API or open weights to self-host. Read our DeepSeek guide before you paste anything.
Pick neither if you work in government, a regulated industry or with patient data and have no approved tool. Ask your IT team first. For an EU-hosted option, see ChatGPT vs Vibe (Le Chat), and for more options read the best ChatGPT alternatives or try our comparison tool. You can practise the prompts below in our free lessons at /learn?tool=chatgpt.
Prompts to copy
Strip a document before you paste it anywhere
Rewrite the text below so it contains no names, company names, email addresses, phone numbers or exact figures. Replace each with a placeholder such as [CLIENT_1] or [AMOUNT_1], and list every replacement at the end so I can put them back. [paste text]
You get: A cleaned version you can use with any AI tool, plus a key to restore it
Brief a long public report
Here is a public report: [paste or upload]. Write a one-page brief for [audience] with the five findings that matter most, the section each comes from, and any claim the report makes without data. End with three questions I should ask before acting on it.
You get: A checkable one-page brief that works in both tools
Check a calculation step by step
We sell [product] at [price] with [unit cost] unit cost and [volume] units a month. Work out monthly profit if we cut the price by 10%, 15% and 20% and volume rises by [x]%. Show every step in a table, then give a one-line recommendation and the assumption it depends on most.
You get: A worked scenario you can verify line by line (turn on Expert Mode in DeepSeek)