A pre-deployment review of an AI bot robots.txt tests one pasted file against 32 documented robots.txt product tokens — the ones used by AI crawlers, AI assistants, model-training controls, and AI-adjacent search crawlers — and reports whether each token's rules Allow or Disallow a path you enter. The AI Bot Robots.txt Checker handles that comparison in your browser using the matching rules standardized by RFC 9309, so the result stays private and reproducible. It does not fetch a website, upload the file, or contact a crawler operator; it only evaluates the exact text and path you supply. Avoiding mistakes in this review means knowing what each row represents, treating path matching as case-sensitive, testing more than one path, and remembering that an "allowed" verdict only means no Disallow rule matched the chosen path under the implemented protocol logic — not that an operator will crawl, index, train on, or honor the file. Treat the report as a pre-publication sanity check, then verify critical tokens against operator documentation and your live /robots.txt response before you treat any row as a binding policy.
What an AI Crawler Review Actually Tests
A robots.txt review against AI bots is narrower than most readers expect. The checker evaluates one pasted robots.txt against a fixed 32-entry product-token table, labels each row with its operator and a purpose category (AI crawler, AI assistant retrieval, model-training control, or AI-adjacent search crawler), and reports an allowed or blocked result for the path you enter. It does not look up DNS, query any crawler, or estimate how a model might behave downstream.
The 32 rows are robots.txt product tokens, not a uniform list of HTTP User-Agent header strings. Some operators publish a dedicated control token — Google-Extended and Applebot-Extended are well-known examples — that signals training or data-use preferences; other rows track retrieval products or directory-sourced entries that the checker labels rather than presents as first-party verified. Because crawler products change over time, no static table can be permanent; that is why the report is framed as a pre-deployment review, not as a binding audit. The protocol logic that ties it together follows RFC 9309: user-agent product tokens are matched without regard to letter case, paths are compared case-sensitively from the start, the longest matching pattern wins, and an Allow rule at equal length beats a Disallow rule.
Mistakes That Invalidate the 32-Token Report
Six recurring mistakes quietly invalidate the report. They are easy to make because robots.txt looks like plain text and the matching rules hide behind a long list.
Treating every row as a literal User-Agent header. Not all 32 tokens are HTTP header strings. Some are dedicated control tokens; others come from supplemental directories. The table distinguishes operator-documented rows from directory-sourced rows so you can weight them correctly. A focused guide on this distinction is at Are All 32 Robots.txt Tokens Literal User-Agent Headers?.
Assuming path matching is case-insensitive. RFC 9309 treats the User-agent product token as case-insensitive but requires path matching to be case-sensitive. /Private and /private are different paths and can produce different results against the same rule set, which is the kind of mistake that quietly exposes or hides entire URL trees.
Testing one path and assuming you are done. The longest-match rule hides edge cases. A homepage test cannot tell you what happens on a /api/ or /drafts/ path, so several representative paths — including one with a query string if you want to model crawler behavior with parameters — are worth running before you publish.
Trusting an allowed row as positive proof. An allowed verdict means no Disallow rule matched the path under the implemented logic. It does not prove the operator crawls, indexes, cites, trains on, or displays the page. Search indexing, snippet controls, training preferences, and live network blocking are separate controls.
Reading merged groups the wrong way. When multiple User-agent groups target the same product token, their rules are combined, and a specific product-token group overrides the wildcard group. A specific Allow rule inside a group that does not name the token you care about will not influence the row for that token.
Ignoring scope limits. The checker accepts at most 500 KiB of UTF-8 input and 5,000 non-empty access rules. A file inside the byte limit can still be rejected by the documented aggregate matching-work cap, so a borderline file deserves a trim before testing.
Run a Pre-Deployment Review in Your Browser
A short, repeatable workflow catches most issues before publication. Each step is taken straight from the tool's verified operating procedure so the result stays reproducible across teammates and reviews.
- Open the AI Bot Robots.txt Checker and paste the exact production robots.txt text into the input box. Keep the file under 500 KiB; files inside that limit can still be rejected if the parser hits its documented aggregate matching-work cap, so trim noise before testing.
- Enter a case-sensitive URL path that begins with a slash. Add a query string if the crawler request you want to model includes one, because the checker compares paths from the start and treats the query as part of the input.
- Run the check. The report lists all 32 product tokens with their operator, purpose category, source status, and an allowed or blocked verdict for your path. Walk down the list and flag any row where the verdict surprises you.
- For each surprising row, identify the matching rule by reading the rule chain — specific product-token group first, wildcard group second — and apply longest-match tie-breaks (Allow wins on equal length, a dollar sign anchors to the end of the path, an asterisk matches any sequence).
- Before deployment, cross-check every critical row against the operator's current documentation. Crawler products change over time, and supplemental directory entries are labeled rather than first-party verified.
Reading the 32-Token Report: A Quick Map
The table that comes back has four columns of context for every row, not just the verdict. The label set is consistent across the 32 rows so you can scan it quickly without re-reading the tool's documentation each time.
| Column | What it tells you |
|---|---|
| Operator | Which company or project owns the token |
| Purpose category | Whether the row is an AI crawler, assistant retrieval, model-training control, or AI-adjacent search crawler |
| Source status | Operator-first-party documented, managed cross-reference, or supplemental directory entry |
| Result | Allowed or blocked for the exact path you entered |
Filter the table to operator-first-party rows first, spot-check the policies that actually carry weight, and treat managed and supplemental rows as secondary signals. A current cross-reference for major products is maintained in the Cloudflare AI crawler reference, and managed robots.txt behavior is documented in the Cloudflare managed robots.txt reference.
After the Report: Live Checks the Tool Cannot Do
The checker is deterministic and offline, so it cannot detect a category of problems that only appear once the file is live. After the report looks right, fetch the production /robots.txt from the exact scheme and host the crawler would use, confirm the response is plain text and returns a success status, and compare that response byte-for-byte with the text you pasted. Even a single space difference can flip a pattern.
The tool also cannot see redirects, CDN overrides, syntax served only to certain clients, incorrect host scope, caching delays, or an unreachable file. A focused walk-through of what the checker does and does not inspect is at Does the AI Bot Robots.txt Checker Fetch Your Live Website?. For high-stakes paths, supplement the report with operator-side tools where they exist — for example OpenAI's publisher guidance and Anthropic's web crawler controls — and check server logs for actual fetch traffic.
Robots.txt is voluntary. It is not authentication, authorization, a firewall, or a contractual enforcement system. A crawler can ignore the file, and publicly listing a sensitive path can advertise it. Protect confidential or paid content with server-side access controls and monitor real traffic separately; treat the report as one input, not as proof.
Hard Limits Worth Knowing
The matching engine enforces three limits that affect what you can paste without surprises. The first is the 500 KiB input cap, which matches RFC 9309's expectation that parsers handle at least that much UTF-8 input. The second is a hard cap of 5,000 non-empty access rules (User-agent, Allow, and Disallow directives), and sitemap or crawl-delay lines do not count toward that limit. The third is an aggregate matching-work budget of 20,000,000 operations that prevents an adversarial long path and a large rule set from freezing the main thread.
Within those limits, paths are compared from their beginning, asterisk and terminal-dollar anchors behave as the protocol defines, comments are removed before interpretation, and an empty Disallow value blocks nothing. If no applicable Allow or Disallow rule matches, the result is reported as allowed. These limits make the result reproducible from the same text and path — useful when a teammate needs to confirm your reading during a review.