Real-time web search

Beyond frozen knowledge

Like every AI model, Grok has a cutoff date for its built-in knowledge. Asked about a decision made last week without any extra tool, it will either say it doesn’t know or, worse, give outdated information in the same confident tone as everything else. Web search fixes exactly that: it lets Grok search the web while it writes, then enrich its answer with up-to-date, sourced information.

How web search works

The mechanism is invisible, but understanding it explains why some answers take longer. When you ask a question that requires recent information, Grok goes through five steps:

1. Grok analyzes your question and decides whether a search is needed
2. It searches the web in real time
3. It synthesizes the results it finds
4. It writes its answer, working in the recent information
5. It cites its sources with clickable links

On grok.com, a dedicated button in the input field turns search on or off for each conversation. Turning it on doesn’t mean Grok will always search: it decides question by question. For a theoretical definition, it draws on its built-in knowledge; for a dated fact, the search almost always kicks in.

Answers you can check

Every answer that comes from a search shows its sources, under the text, with links to the original pages, and Grok clearly indicates when information comes from the web rather than from memory. Make a habit of opening at least one of those links: thirty seconds is enough to tell an official announcement from a blog that paraphrases it badly. In a client file or a regulatory memo, that traceability is the only thing that makes the answer defensible in front of someone else.

The situations that call for a search are easy to spot. A question about institutional news is one of them:

What are the Federal Reserve's latest announcements on interest rates?

So is fast-moving financial data, since no stored value would survive more than a few hours:

What's Tesla's current stock price?

The same logic applies to tech watch, where versions follow one another quickly:

What's new in the latest version of Python?

Finally, fact-checking is the most valuable use, as long as you phrase the question as a hypothesis to test rather than a claim to confirm:

Is it true that the European Union adopted new
AI regulations this week?

Control search from the API

For developers, web search is available through the Responses API. You turn it on by adding a tool to the request:

response = client.responses.create(
    model="grok-4.5",
    input="What are the latest advances in AI?",
    tools=[{"type": "web_search"}]
)

The API lets you limit the search to specific domains, five at most, or exclude some. A monitoring assistant restricted to trusted sources gives noticeably sturdier answers:

tools=[{
    "type": "web_search",
    "allowed_domains": ["reuters.com", "bbc.com"]
}]

Note that you can’t use the allow list and the exclude list at the same time: the two parameters are mutually exclusive. An advanced setting also lets Grok analyze images it comes across during the search. It then interprets charts, infographics, and photos found online, which matters for pages where the key information is locked inside a figure.

What search doesn’t do

Two habits will save you some disappointments. The first is about budget: search uses extra resources and is billed on the API, so turning it on by default for a high-volume service costs a lot for a gain that’s sometimes zero. The second is about judgment: the quality of the results depends on the quality of the available sources, and Grok can misread a page’s context, reading a historical figure as a current one, or attributing a quote to the journalist rather than the person interviewed. For a critical decision, a human review of the sources is non-negotiable.

Key takeaways

• Web search gives Grok access to real-time information
• Answers include citations with links to the original sources
• Domain filtering lets you target or exclude specific sources
• On the API, you turn on web search with the web_search tool
• Always check the sources for critical information