Yes, you can check an AI bot robots.txt file entirely in your browser without uploading it, fetching a live site, or contacting a crawler operator. The AI Bot Robots.txt Checker is a local tool that takes the exact robots.txt text you want to review and compares it against 32 current robots.txt product tokens used by AI crawlers, AI assistants, model-training controls, and AI-adjacent search crawlers. You enter a URL path, run the check, and read an allowed or blocked result for every token in the table. The whole evaluation stays in your browser memory, uses the core matching rules standardized by RFC 9309, and reproduces the same result from the same input every time. That makes it well suited for a pre-deployment review of a robots.txt file before you publish it, and useful for sanity checks on a file already in production, as long as you paste the exact text. Because the checker does not fetch, redirect, or upload, it cannot see what your server is actually serving, but it can show you, repeatably, what your pasted rules would do for a given path.
What the in-browser checker evaluates
The checker evaluates one pasted robots.txt file against a fixed 32-entry table of robots.txt product tokens. Those entries are not a promise that every string appears verbatim as an HTTP User-Agent header; some rows are dedicated control tokens such as Google-Extended or Applebot-Extended that operators publish specifically for model-training or data-use preferences, while other rows represent crawler or assistant retrieval products. The table labels each operator, purpose category, and source status so those distinctions remain visible inside the report. For OpenAI and Anthropic products, the tokens are taken from primary operator documentation. Both Cloudflare's AI bot and crawler traffic reference and its managed robots.txt documentation provide a current cross-reference for major products; supplemental Radar directory tokens are labeled accordingly rather than presented as operator-first-party verified.
Because the checker matches product tokens without regard to letter case, "GPTBot" and "gptbot" end up in the same group. When multiple groups target the same product token, their rules are combined. A matching product-token group takes precedence over the wildcard group, while the wildcard group applies when no specific group matches. This is the same hierarchy RFC 9309 describes, and it is the reason a group targeted at a single crawler can override a blanket rule without removing the broader fallback.
You can read a deeper breakdown of what the rows represent in the related guide on whether all 32 tokens are literal User-Agent headers, including how operator-published training-control tokens differ from retrieval crawler tokens.
How to run an AI crawler check in your browser
The three-step workflow takes the same robots.txt text you intend to publish and a representative URL path, then evaluates both together.
- Paste the exact robots.txt text you want to review and keep it under the 500 KiB limit. The checker accepts at most 500 KiB of UTF-8 input and 5,000 non-empty access rules, so a file within the byte limit can still be rejected by an aggregate work limit designed to keep the main thread responsive.
- Enter a case-sensitive URL path beginning with a slash, then run the check. The path may include a query string when that is part of the crawler request you want to model. Matching is case-sensitive for paths, so /Private and /private can produce different results.
- Review every matched rule and verify critical product tokens against current operator documentation before deployment. Crawler products change over time, so a blocked result for a row you depend on should be confirmed against the operator's latest page before you call the policy final.
How to read the 32-row allowed and blocked table
Each row produces an allowed or blocked verdict for the entered path under the implemented protocol logic. The verdicts follow the rules standardized by RFC 9309, summarized in the table below.
| Rule | Outcome |
|---|---|
| Matching product-token group | Takes precedence over the wildcard group |
| No specific group matches | Wildcard group applies |
| Allow and Disallow both match with equal length | Allow wins |
| Longest matching pattern | Selected as the rule that decides access |
| * inside a pattern | Matches any sequence of characters |
| $ at the end of a pattern | Anchors the pattern to the end of the path |
| Empty Disallow value | Does not block anything |
| No applicable Allow or Disallow rule matches | Access is reported as allowed |
| Comments inside the file | Removed before rules are interpreted |
Within the applicable group, Allow and Disallow patterns are compared against the path from its beginning. The most specific matching pattern wins, and when equally specific Allow and Disallow rules both match, Allow wins. An asterisk matches any sequence of characters, and a dollar sign at the end anchors a pattern to the end of the path. Comments are removed before rules are interpreted, and lines that are not User-agent, Allow, or Disallow directives do not affect the result. Sitemap and Crawl-delay lines may be meaningful to particular crawlers, but they are outside this access-decision report.
Why browser-only processing matters for a pre-deployment review
Running the check in your browser keeps the file private and deterministic. The tool does not fetch a website, upload the file, or contact a crawler operator, so the only thing the evaluation sees is the pasted text and the entered path. That matters for two practical reasons. First, you can paste draft rules that are not yet live on your origin or staging server and verify their behavior without exposing them. Second, the same input always produces the same output, which makes it easy to step through several paths, compare wildcard and targeted groups, and share the same verdict with a teammate or reviewer.
The checker is also designed to be conservative about what it claims. An allowed result means only that the pasted rules do not request a block for the selected path under the implemented protocol logic; it does not prove that the operator will crawl, index, cite, train on, or display the page. A blocked result likewise does not prove enforcement or removal from an index. Search indexing, snippet controls, training preferences, and live network blocking are separate controls. Robots.txt is voluntary, not authentication, authorization, a firewall, or a contractual enforcement system, and a crawler can ignore the file. Treat the checker as a fast, repeatable review of your rules, then back the result with authentication, network controls, and traffic monitoring for any path that needs enforceable protection.
What the checker cannot see, and what to do after publishing
Because the checker does not fetch URLs, it cannot detect redirects, CDN overrides, syntax served only to certain clients, incorrect host scope, caching delays, or an unreachable file, and it cannot confirm what is currently deployed. Publicly listing a path in robots.txt can also reveal it, so manage confidential or paid content with server-side access controls. Those limitations keep the tool private and deterministic, but they make a post-publish checklist important.
After publishing, fetch the live /robots.txt from the exact scheme and host, confirm the response is plain text and returns successfully, and then verify behavior in available operator tools or server logs. Treat the in-browser report as the first pass, and the live deployment as the source of truth.