Does Claude search the web by default?

There is no published default for web search on claude.ai. As of October 2026, search in the consumer app is a toggle the user sets. Anthropic does not state which position a new user starts in.

The API is a separate product with separate settings. Anthropic's API configuration enables web search at the organisation level by default, but that describes developer requests, not the app your customers use. Treating one as proof of the other is the most common mistake in Claude testing.

There is a third layer. Even when search is available, Claude decides per question whether to use it. In apps built on the API, the integrator's system prompt steers that decision. So "Claude" can mean three different retrieval states for the same question.

What this means for you: a Claude answer about your brand tells you little until you know whether it was grounded. For the wider pattern across vendors, see whether AI model APIs search the web by default.

Each surface sets search differently. The table summarises what is documented as of October 2026.

Two more conditions matter.

• Model choice. The claude.ai app lets users select between models, and the selected model changes what the model knows without search.
• The model's own judgement. Search being available does not mean a search runs. Claude chooses per query.

This is why the same prompt can return different answers in different places. The page on why Claude answers differently in different apps covers the surface differences in more depth.

Anthropic's web search tool documentation is specific about the API. Search results expose a URL, a title and page_age, described as when the site was last updated. Claude cites text spans, with each cited_text capped at 150 characters. The evidence base records the price as $10 per 1,000 searches plus tokens.

What the documentation does not give you:

• A default search state for claude.ai.
• Any statement that API behaviour matches consumer behaviour.
• How Claude decides when to search.
• Whether page_age affects which pages get chosen. Exposing a field is not the same as weighting it.

On the crawler side, Anthropic's support page separates three agents: ClaudeBot (training), Claude-SearchBot (search quality) and Claude-User (user-triggered fetches). Blocking one does not block the others. Anthropic also warns that IP blocking "impedes our ability to read your robots.txt file." Our digest of Anthropic's crawler documentation lists the details.

The honest reading: the access rules are documented, the consumer search default is not.

A Claude answer with search off comes from training data frozen at a cutoff. Nothing you publish this quarter reaches it. A Claude answer with search on can draw on your current pages, if Claude-SearchBot can reach them and they render without JavaScript.

Mix the two and the numbers stop meaning anything. The 99Visibility evidence base notes that any single AI visibility score averages an unobserved mixture of answers given with and without live retrieval. Claude is a sharp case because the consumer default is unknown.

Three practical consequences:

1. Trends can be fake. A score that moves because the test switched search state looks like a real change.
2. Citation metrics can be unscoreable. With search off there are no sources, so a citation rate has nothing to count.
3. Competitor comparisons break. Two tools testing Claude in different states will disagree, and both can be right.

If your report shows Claude far below other engines, read why Claude scores low in a visibility report before acting on it.

You can't control the claude.ai default. You can control what you log. Make these fields mandatory for every Claude check.

1. Surface. claude.ai, the API, or a named third-party app.
2. Search state. On, off, or unknown. For the app, note the toggle position at the time of the test.
3. Whether a search actually ran. Visible citations or returned search results are the evidence. No citations means you cannot assume grounding.
4. Model. The exact model selected or called.
5. Date. Defaults and models change, so the date is part of the result.
6. Retrieved and cited sources. Through the API, keep both lists. The retrieved vs cited logging playbook shows how.

Then test both states deliberately rather than relying on a default. The trade-offs are covered in whether to test with search on or off. For an ongoing setup, see tracking Claude's answers about your brand.

One thing in your control regardless of search state: check that your robots.txt and firewall let Claude-SearchBot through, and that key facts appear in the HTML before JavaScript runs. Those decide whether a search-on answer can use your pages at all.

Does the Claude API search the web automatically? Web search is enabled at the organisation level by default on the Claude API, according to the evidence reviewed for this page. That makes the tool available, but Claude still decides per request whether to search, and the developer's system prompt can steer it. None of this describes the claude.ai consumer app, which has its own user toggle and no published default.

How can I tell if a Claude answer used web search? Look for citations. When Claude searches, it cites specific text spans from the sources it used. Through the API you also receive the search results themselves, with URLs, titles and page_age. If an answer shows no citations and you have no search results logged, treat its retrieval state as unknown rather than assuming it searched.

Does blocking ClaudeBot remove me from Claude search answers? Not by itself. Anthropic documents ClaudeBot as a training crawler, separate from Claude-SearchBot, which supports search quality, and Claude-User, which fetches pages for user requests. Each is a separate robots.txt entry. If you want to appear in search-on answers, check that Claude-SearchBot is allowed and that your firewall or CDN does not block it.

Can I make Claude mention my brand when search is off? Not this quarter. With search off, Claude answers from training data fixed at its knowledge cutoff. Nothing you publish now reaches that answer until a future model is trained, and no vendor measures whether allowing training crawlers changes brand recall. What you can influence is the search-on path: crawler access, rendering, and stating clear facts on pages that can be fetched.

Is a Claude result from a visibility tool the same as what users see? Only if the tool matched the user's surface, model and search state. Most tools call the API, which has different settings from claude.ai. A tool that tests with search off measures training data, while a user with search on may see a grounded answer. Ask any tool which state it tested, and compare only results recorded the same way.