Domain Tools
Browse 7 free online domain tools. All tools run instantly in your browser - no download or sign-up required.
Look up WHOIS data for any domain to see registration details, nameservers, registrar information, creation and expiration dates, and contact information.
Look up WHOIS data for any IP address to find the network owner, ASN, allocated range, abuse contact, and registration details from regional registries.
Discover all subdomains for any domain. Uses certificate transparency logs, DNS enumeration, and other techniques to map the complete domain infrastructure.
Check any URL to verify it's accessible and working. See HTTP status codes, redirect chains, response times, and identify broken or problematic links.
Analyze any website's robots.txt file. Validate syntax, check crawl directives, identify blocked resources, and ensure proper search engine configuration.
See which AI crawlers (GPTBot, ClaudeBot, PerplexityBot, Google-Extended) a website allows or blocks in robots.txt, and whether it publishes an llms.txt.
Generate a correct robots.txt in your browser: choose a crawl policy, block paths, add a sitemap and crawl-delay, and opt out of AI crawlers like GPTBot and ClaudeBot.
How this tool works: This tool runs in your browser and on our server in real time. Depending on the tool, results are computed directly from the input you provide or retrieved from live, authoritative data sources at the moment you run a lookup. We do not sell your data, and your lookups are kept private — any history shown here is stored only on your device.