Network Tools — 25 Free Online Tools
Diagnose DNS, WHOIS, SSL, IP, email, proxies and internet speed from your browser. Every lookup runs client-side against live public endpoints.
Diagnostics for problems sitting on infrastructure you do not control. The DNS and WHOIS Lookup and the Domain Age Checker answer who owns a name and when it was registered, the SSL Certificate Checker shows the full chain and the expiry date, and the Ping Test separates latency from jitter and loss so you know whether a slow request is a long path or a congested one.
2FA Authenticator - TOTP Generator & Decoder
Decode otpauth QR codes and URIs, generate TOTP and HOTP codes, and find out why your authenticator code is rejected. Nothing is uploaded.
AI Crawler Access Checker - GPTBot
Free AI crawler access checker. Audit robots.txt against 19 AI bots and validate llms.txt to spec. See the exact rule that blocks GPTBot. No signup.
AI Crawler Log Analyzer - GPTBot & ClaudeBot Traffic
Free AI crawler log analyzer. Drop an Apache, nginx, IIS or Cloudflare log: GPTBot, ClaudeBot and PerplexityBot hits, status codes, spoof checks.
CORS Header Generator - Allow-Origin Tool
Free CORS header generator. Configure Allow-Origin, methods, headers, credentials. Generate Nginx, Apache, Express, Flask, Workers snippets.
DNS & WHOIS Lookup - Check Domain Records
Free DNS lookup and WHOIS checker. Query DNS records (A, AAAA, MX, NS, SOA, TXT) and domain registration info instantly. No signup required.
Domain Age Checker - Free WHOIS Domain Age Lookup
Free domain age checker. Check how old any domain is, creation date, expiry date, registrar, and nameservers. Instant WHOIS lookup, no signup required. AI.
Email Authentication Checker - SPF DKIM DMARC Check Online
Free email authentication checker. Check SPF, DKIM, and DMARC DNS records for any domain. Fix email deliverability. We check real DNS records.
Email Header Analyzer - SPF, DKIM & DMARC Verdict
Read raw email headers: SPF, DKIM, DMARC and ARC verdicts, alignment against the From domain, delivery delay attributed to one hop, and spoofing signals.
Email Verifier - Verify Email Addresses Instantly
Free email verifier. Check if email addresses are valid and can receive messages. Detect disposable emails and SMTP issues. No signup required.
File Checksum Verifier - Verify MD5 SHA-1 SHA-256 SHA-512
Verify file checksums after downloading. Compute MD5, SHA-1, SHA-256, SHA-512 hashes from any file. 100% private browser processing, no upload.
Free Package Tracker - Track Any Carrier
Free universal package tracker. Enter any tracking number and automatically detect the carrier. Track USPS, UPS, FedEx, DHL, Amazon, and more. No signup.
Free Speed Test - Internet Speed Checker
Free internet speed test. Check your download speed, upload speed, and latency instantly in your browser. No software install needed.
HTTP Status & Header Checker Online
Free HTTP status checker. Check response codes, security headers, redirect chain, and response time for any URL. AI cannot check real HTTP headers - we do.
IP Address Lookup - Find Your IP Address
Find your public IP address, then the ISP, country, city and connection type behind it. Paste any address to look it up too. No signup, lookups not stored.
Is It Down? - Website Down Checker
Free website down checker. Check if any website is down for everyone or just you. Real-time status, response time, and HTTP code. No signup, 100% free.
Ping Test - Latency, Jitter & Packet Loss
Free online ping test. Measure latency, jitter and packet loss to any host from your browser. See if lag is your connection or the server. No signup.
Port Checker - Test Open Ports Online Free
Free port checker. Test up to 25 TCP ports from outside your network and get open, closed or filtered with latency, no signup.
Proxy Checker - Free IP Proxy Detection Tool
Free online proxy checker. Detect if an IP address is a proxy, VPN, or Tor exit node. Check IP geolocation, WHOIS, and open proxy ports.
REST API Tester - Free Online HTTP Client
Free online REST API tester and HTTP client. Send GET, POST, PUT, PATCH, DELETE requests with custom headers and body. View response status, headers.
SEO Checker - Free Website Audit With Fixes You Can Paste
Free SEO checker. Reads one page the way a crawler would: indexability, robots.txt, 19 AI crawlers, JSON-LD, meta tags, and the tag to paste for each fix.
Sitemap Audit - Sitemap Errors & Noindex
Free sitemap audit. Finds the errors Google reports: 404s, redirects, noindex pages, blocked URLs, bad lastmod, duplicates. Gets you a clean sitemap.xml.
SSL Certificate Checker - Test Website Security
Free SSL checker. Scan any website for TLS security and certificate validity. Get grade A+ to F. No signup. AI cannot test real SSL certificates.
Subnet Calculator - IPv4 IPv6 CIDR VLSM Supernetting
Free subnet calculator for IPv4 and IPv6. Bit-exact CIDR, VLSM, supernetting, overlap detection. No signup. AI cannot reliably compute subnets - we do.
URL Metadata Extractor - Link Preview and Meta Tags
Free URL metadata extractor and link preview tool. Extract OG tags, Twitter cards, JSON-LD, SEO meta, and headings from any URL. See how your link looks.
User Agent Parser - Browser OS Device Detection Online
Free online User Agent parser. Identify browser, OS, device, and bot from any UA string. Detect Googlebot, GPTBot. 100% private, no upload.
Frequently Asked Questions
4 Q&AWhat network diagnostics are available?
There are 25 tools: 2fa authenticator, ai crawler access checker, ai crawler log analyzer, cors header generator, dns & whois lookup, domain age checker, email authentication checker, email header analyzer, email verifier, file checksum verifier, free package tracker, free speed test, and 13 more.
Do the DNS, WHOIS, and SSL lookups expose my IP or query targets to a third party?
Yes, those three tools must contact public authoritative servers (DNS resolvers, WHOIS servers, certificate transparency logs) to do their job, so the domain or IP you query is visible to those services the same way a terminal `dig` or `whois` command would be.
Is the speed test accurate?
The speed test downloads and uploads a small payload from a Cloudflare edge server to estimate throughput. Results are influenced by your network conditions, Wi-Fi signal, and VPN; for SLA-grade measurements use a wired test against a known reference server.
Are these tools safe for production network troubleshooting?
Yes. All 25 network tools use standard read-only protocols (DNS, WHOIS, HTTPS HEAD/GET, certificate inspection) and do not modify remote systems. They are appropriate for production reconnaissance and incident triage.
How to Use These Network Tools
guideEvery network tool below runs entirely in your browser — no signup, no upload, no watermark. To find a specific tool, type a name, keyword, or scenario into the search box and the list filters instantly. Popular network tools are linked in the summary at the top; click any card or link to open the tool and follow the on-screen instructions. Hover any tool card to read its full description, then click its name or button to open it.