How to Fact-Check DeepSeek's Answers Before You Use Them

The short version

DeepSeek’s own documents tell you not to rely on its answers without checking. Its terms say outputs “may contain errors or omissions and are for your reference only”. Use it to find and draft. Use real sources to confirm.

What to check every time

• Numbers: prices, statistics, dates, percentages
• Names: people, companies, products, places
• Quotes: anything in quotation marks
• Laws, rules and deadlines: these vary by place and change often
• Links: make sure the page exists and says what DeepSeek claims

Step by step

1. Turn on Search for factual questions, so DeepSeek looks up current pages. See use DeepSeek Search.
2. Ask for sources. “List the pages you used, with links and dates.”
3. Open the sources. Confirm each key claim on the page itself. Prefer official and primary sources.
4. Check quotes word for word. If you can’t find the quote, don’t use it.
5. Ask DeepSeek to list its weak spots. The answer gives you a checklist of what to confirm first.
6. Label it. If you publish the result, say AI helped, as DeepSeek’s terms require.

Prompts to copy

Separate facts from guesses:

For your previous answer, list every factual claim as a bullet.
Mark each one: (a) from a source you can link, (b) general knowledge, or (c) your inference.
Give links for (a).

Find weak spots:

What in your answer is most likely to be wrong or out of date? Explain why,
and tell me what source I should check for each.

Check a document summary:

For each point in your summary, quote the exact sentence from the document it's based on.
If a point isn't directly supported, say so.

Example

DeepSeek says: your city’s sign permit costs $150 and takes two weeks, and links to a blog post from a sign company.

How you check: find the permit page on your city’s own website. If the fee or timeline there differs, use the city’s figure and note the date you checked. The blog post may be out of date or about a different city.

Mistakes to avoid

• Checking only the parts that look wrong. Errors usually look plausible.
• Accepting a source because it exists. Read whether it actually supports the claim.
• Trusting visible reasoning as proof. DeepThink’s steps can contain mistakes too.
• Publishing without a label. DeepSeek’s terms also say you must not remove or hide the AI-generated labels it adds.

When not to use it

Its terms say not to treat outputs as professional advice for medical, legal or financial questions, and require human review when outputs are used for important decisions about people, such as employment, housing, credit or insurance. Use DeepSeek to prepare, then rely on a professional or the official source.

Related: use DeepSeek Search and write better prompts for DeepSeek.