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Network, Privacy, Security & Developer Utilities 2026

AI Crawler Verification: Is That Bot Really Who It Says?

A user-agent is a sentence a client writes about itself. Anyone can send Googlebot/2.1 from any machine on earth, and your access log will record it exactly as it records the real thing. That is why the ten tools in this category ignore the header entirely and test the two things a client cannot forge: the source address, and what the operator’s own nameservers say about it.

Each operator makes that harder in a different way, which is why there is a page per operator rather than one generic checker. Google publishes five separate range files and documents reverse DNS. Microsoft documents reverse DNS too, and its published list disagrees with it on at least one subnet. OpenAI publishes four files with overlapping prefixes and no reverse DNS at all. Anthropic publishes one combined file for three crawlers. Perplexity declares thirty-two addresses in total and has an open dispute about crawling from others.

The thing every one of these tools does that most checkers do not is distinguish the check failed from the check could not run. A vendor feed that times out is not evidence against an address, and reporting it as one is how site owners end up blocking real crawlers and losing indexing. Start with the Bot IP Verifier if you are not sure which operator you are looking at, then move to the operator page for the detail. When you have decided what to allow, the AI Crawler Blocker writes the robots.txt and firewall rules from the same live ranges.

Network & IP Tools: Diagnose Connectivity Issues Fast

Network problems are frustrating because they are invisible. Your website might be down because of a DNS misconfiguration, a blocked port, or a blacklisted IP — and you cannot tell which one without the right diagnostic tool. Our network tools category includes 25 utilities that cover every layer of network analysis.

Start with IP Geolocation to verify your public IP and location, then follow the address up into the routing layer: the ASN Lookup tells you which autonomous system announces it and who to contact about abuse, and ASN IP Ranges exports every block that network announces in iptables, nftables, nginx or Cisco syntax when you need to allow or block the whole operator rather than one address. Use DNS Lookup to check A, MX, and CNAME records. Run the Port Scanner to find open ports that could be security risks. Test your connection quality with Speed Test and Ping. For advanced users, the CIDR Calculator and Subnet Calculator handle IP range planning.

An address is one number written four ways, and the conversion tools in this category move between them. IP to Decimal turns a dotted quad into the single integer a database should store, IP to Binary shows the individual bits that subnet masks operate on, and IP to Hex decodes the obfuscated links that turn up in phishing mail. The Phone Number to IP Address Converter runs the same arithmetic on a phone number, which is a novelty conversion used for puzzles rather than a lookup — and the page says so plainly, because no tool can find somebody’s real IP from their number.

If you are dealing with email deliverability issues, check your IP against blacklists with our Blacklist Check tool. Read our IP reputation score guide and our fix 550 RBL blocked sender guide for step-by-step solutions.

Domain, Email & Developer Tools: Professional Utilities

Our SSL Checker verifies certificate validity, expiration, and trust chain — essential before launching any website. The Headers Analyzer inspects HTTP security headers like HSTS, CSP, and X-Frame-Options. Verify domain ownership with WHOIS Lookup and trace redirect chains with the Redirect Checker.

Email is where the ground moved most in the last year. Gmail replaced deferrals with permanent rejections for non-compliant bulk mail in November 2025, Outlook applied its own hard refusal the same month, and in May 2026 the IETF published RFC 9989 and its companions, which replace the original DMARC specification from 2015. A domain that was merely untidy in 2024 can now have its mail refused outright.

Four tools cover the questions that raises. Verify an address before you send to it with the Email Verifier, and keep throwaway signups out with the Temp Email Checker. When a message has already arrived and you need to know whether it is genuine, the Email Header Analyzer reconstructs the delivery path, marks which hops can be trusted, and works out SPF, DKIM and DMARC alignment itself rather than reprinting the receiving server’s verdict. And to check your own domain before enforcement bites, the DMARC Checker validates the published record against RFC 9989, including the np tag that closes the non-existent-subdomain gap.

For the reputation side of deliverability, read our IP reputation for bulk email and cold emailing guide.

Developer utilities include Base64 Encoder, Hash Generator (MD5/SHA-256/SHA-512), JSON Formatter, Punycode Converter, URL Encoder, and Password Generator. All run client-side for maximum security.