Network utilities
Every tool runs in your browser. No accounts, no tracking beyond standard analytics. Hover (or tap) any tool to see what it does.
🌐 Network
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IP Lookup
IP Lookup & Geolocation
Look up any IPv4 or IPv6 address — city, region, country, ISP, ASN, timezone, map. Free, no login.
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IP Converter
IP Converter
Convert IPv4 addresses between dotted-decimal, binary, hex, and integer. Paste any format and see all the others.
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WHOIS Lookup
WHOIS / Domain Lookup
Find out where a domain is registered — registrar, expiry, name servers. Useful for old domains in DNS you don't recognize.
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DNS Propagation
DNS Propagation
Query records across 8 public resolvers worldwide — Cloudflare, Google, AdGuard, NextDNS, DNS.SB, Alibaba, Tencent, FlatusLifir.
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DNS Lookup
DNS Lookup
Query A, AAAA, MX, TXT, NS records against Cloudflare, Google, and Quad9 simultaneously. Spot poisoning and stale cache.
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Reverse DNS
Reverse DNS
Look up the PTR record for any IPv4 or IPv6 address. Essential for email deliverability and log analysis.
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MAC Vendor Lookup
MAC Vendor Lookup
Decode any MAC address to its manufacturer. Detects randomized/private MACs. Works offline for common vendors.
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Domain Infrastructure
Domain Infrastructure
See who actually hosts a domain — web, mail, and DNS providers in one view. Like NirSoft DomainHostingView in your browser.
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CGNAT Detection
CGNAT Detection
Detect whether your ISP has placed you behind Carrier-Grade NAT. Critical for self-hosting and port forwarding.
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🔢 Subnetting
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Subnet Calculator
Subnet Calculator
CIDR ↔ mask ↔ host count. Network and broadcast addresses, usable host range.
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CIDR Range Tool
CIDR Range Tool
Expand any CIDR block to start/end IPs, total addresses, and usable host count.
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MTU / MSS
MTU / MSS Calculator
Find the right MTU and matching TCP MSS for your network. Includes VPN tunnel overhead and PPPoE.
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Bandwidth & Transfer
Bandwidth & Transfer
How long will 500 GB take on a 100 Mbps link? Convert between bps, Bps, and GB/hr.
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⚡ Speed & Performance
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Speed Test
Speed Test
Test your connection speed against Cloudflare's edge — download, upload, latency, jitter. No popups, no fake boosters.
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VoIP Quality Test
VoIP Echo Test
Real WebRTC echo against Cloudflare. Hear the round-trip delay your SIP traffic actually experiences. Plus PBX port reachability check.
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🔒 HTTP & SSL
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HTTP Headers
HTTP Headers Inspector
Inspect any URL's response headers. Detects HSTS, CSP, CORS, cookies, server fingerprint, and security misconfigurations.
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SSL/TLS Cert Inspector
SSL/TLS Cert Inspector
Inspect any HTTPS site's TLS certificate — subject, issuer, SANs, key size, expiration, full chain.
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✉️ Email
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Email Headers
Email Header Analyzer
Paste raw email headers — hop-by-hop trace with TLS info, SPF/DKIM/DMARC results, transit timing, and suspicious-pattern flags.
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Email Health
Email Health Check
One-shot diagnostic for any domain. Checks MX, SPF, DMARC, and DKIM in parallel with severity-tagged findings.
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Spam Score
Email Spam Score
Paste a subject + body, get a SpamAssassin-style score with rule-by-rule breakdown. Find out why your email is going to junk.
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Blacklist Check
DNSBL Blacklist Check
Test any IP against 6 major email blacklists — SpamCop, Barracuda, DroneBL, Mailspike, PSBL, UCEPROTECT.
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🛡️ Security & Privacy
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Password Entropy
Password Entropy
How strong is your password really? Calculate bits of entropy and time-to-crack against modern hardware.
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WebRTC IP Leak
WebRTC IP Leak Test
Detect whether WebRTC exposes your real IP — critical when using a VPN. Local, public IPv4, IPv6, and mDNS detection.
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Hash Generator
Hash Generator
Generate cryptographic hashes of any text. MD5, SHA-1, SHA-256, SHA-384, SHA-512. Runs entirely in your browser.
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🛠️ Dev Utilities
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JWT Decoder
JWT Decoder
Decode any JWT token to see its header, payload, and signature. Stays in your browser — tokens are never sent anywhere.
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Base64 Encode/Decode
Base64 Encode / Decode
Encode or decode base64 (standard and URL-safe). Pure-browser, supports UTF-8 multi-byte text.
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UUID Generator
UUID Generator
Generate one or many UUIDs (v4 random, v7 time-ordered, or Nil). Cryptographically random, browser-side.
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Look-up tables
Quick-reference pages for the things you Google constantly.
Private IP Ranges
RFC 1918 + CGNAT + link-local + loopback. The cheat sheet you keep half-remembering.
Open →Default Router IPs
Linksys, Netgear, ASUS, TP-Link, Ubiquiti — what's the default gateway and login?
Open →Port Reference
What runs on port 5060? On 8443? The ports cheat sheet for sysadmins and gamers.
Open →DNS Record Types
A, AAAA, MX, TXT, CNAME, NS, SOA, SRV, CAA — what they do and when you'd use them.
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Why Tank?
Most "what's my IP" sites are sad. Stuffed with autoplay video, popup ads, fake "your computer is infected" warnings, and a stripe at the top that says BUY OUR VPN. We thought: that's a lot of work to dress up a number.
Tank shows you the number. Tank is a real cat in northern Vermont. He's a tabby with strong opinions and zero patience for nonsense. We think he's the best mascot in the IP-lookup business, and we're not going to argue with you about it.
Beyond the front door, this is a serious tool site for sysadmins, network engineers, gamers configuring port forwards, and home users trying to figure out why their router won't talk to their printer. Everything runs in your browser. Nothing you type or paste is sent to us. The only thing we ever know about you is what your browser sends to Cloudflare's edge — same as visiting any other site on the internet.