Website Robots.txt Checker
Find mistakes in robots.txt before they cost you traffic. The checker fetches the file, handles missing files and server errors the way Google does, parses it to the robots exclusion standard and reports syntax problems, a Disallow: / that blocks everything, unsupported Noindex lines, crawl-delay, the content type, a byte-order mark and a missing Sitemap line. It shows the groups and their rules, tests common paths for Googlebot and checks that the home page’s own CSS and JavaScript are not blocked.
- Encrypted connection
- No sign-up
- Free to use
How to use Website Robots.txt Checker
- Enter a website.
- Click “Check robots.txt”.
- Read the problems found.
- Test your own URLs with the Robots.txt Tester.
Website Robots.txt Checker features
Standard parsing
RFC 9309 rules.
Blocked assets
CSS and JS of the home page.
Status handling
404 and 5xx explained.
Groups and rules
Per user agent.
Safe fetching
Public addresses only, with size and time limits.
Common paths
Tested for Googlebot.
When to use Website Robots.txt Checker
- Launch checks for new sites.
- Investigating lost traffic.
- Reviewing CMS defaults.
- Before changing crawl rules.
Website Robots.txt Checker FAQ
What happens if robots.txt returns 500?
Google stops crawling the site until the file is reachable again.
Is a missing robots.txt a problem?
No – crawlers then assume everything is allowed.
Why not block CSS and JavaScript?
Google renders pages like a browser; blocked files make pages look broken to it.
Does robots.txt remove pages from search?
No. It blocks crawling; use noindex to keep pages out of results.
Small file, big impact
One wrong line in robots.txt can hide a whole site from search engines. Checking it after every change is cheap insurance.
Remember that robots.txt is public: do not use it to hide sensitive URLs.
How it works: our server downloads the page once through a guarded fetcher that only connects to public addresses, follows a limited number of redirects and stops after a size and time limit. The HTML is then analysed in your browser as inert text – scripts on the page never run and nothing is stored.
What it cannot see: content and resources that a page adds with JavaScript after it loads, pages behind a login, and servers that block automated requests. For those, open the page in your browser, use its developer tools, or paste the page source where the tool offers a paste option.
Use the results as a starting point: fix the items marked red first, review the yellow warnings in context, and run the check again after a change. Requests are rate-limited to keep the service fair; if you check many pages in a row, wait a few minutes.
Related checks on this site cover the rest of a technical review – speed and Core Web Vitals, security headers, structured data, accessibility and SEO signals – so you can work through a whole site audit one topic at a time.
Who it is for: site owners checking their own pages, developers debugging a release, SEO and marketing teams auditing clients or competitors, and students learning how the web works. No account or installation is needed, and the results are plain text and tables you can copy into a report or ticket.