Network Tools — 17 Free Online Tools
17 free online network tools. No signup required.
Network diagnostics and lookup tools. Check DNS, WHOIS, SSL, IP, email, package tracking, proxy detection, and internet speed. All in your browser.
Need a JSON formatter online or an image compressor free? DevTools Hub has both, plus 279 free online developer tools that run entirely in your browser. Network Tools are free online developer tools you can use instantly — no signup, no upload, 100% private. Popular free tools in this category include a free DNS lookup tool, an IP address lookup, an internet speed test, or an SSL certificate checker — all free to use online, no signup required. DevTools Hub is a collection of 279 free online developer tools that run entirely in your browser — no signup, no upload, no watermark. Popular tools across the whole site include a free JSON formatter online, a free image compressor free, a free online video compressor, and a free online calculator.
CORS Header Generator - Access-Control-Allow-Origin Headers
Free CORS header generator. Configure allowed origins, methods, headers, credentials. Generate Nginx, Apache, Express, Flask, Cloudflare Workers snippets. Preflight simulation. AI gets CORS wrong - we don't.
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 with instant WHOIS lookup. See creation date, age in years/months/days, expiry date, registrar, and nameservers. No signup. AI cannot check real WHOIS records - we do.
Email Authentication Checker - SPF DKIM DMARC Check
Free email authentication checker. Check SPF, DKIM, and DMARC records for any domain. Fix email deliverability. AI cannot check real DNS records - we do.
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, no upload, no signup.
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 - Response Code Security Audit
Free HTTP status checker. Check response codes, security headers, redirect chain, response time. AI cannot check real HTTP headers - we do.
IP Address Lookup - Find Your IP Address
Free IP address lookup tool. Find your public IP, location, ISP, and geolocation data instantly. No signup required.
Is It Down? - Website Down Checker
Free website down checker. Check if any site is down for everyone or just you. Real-time HTTP status, response time. No signup. AI cannot check real-time website status - we do.
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 & API Tester
Free online REST API tester and HTTP client. Send GET, POST, PUT, PATCH, DELETE requests with custom headers. View real response status, timing, headers, and body. No signup, 100% private. AI cannot make HTTP requests - we do.
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 & Meta Tag Analyzer
Free URL metadata extractor. Extract OG tags, Twitter cards, JSON-LD, and SEO meta from any URL. See link previews before sharing. No signup.
User Agent Parser - Browser OS Device Detection Online
Free online User Agent parser. Parse any UA string to identify browser, OS, device, and bot. Detect Googlebot, GPTBot. 100% private, no upload.
Frequently Asked Questions
4 Q&AWhat network diagnostics are available?
Sixteen tools: DNS lookup, WHOIS, IP address lookup, SSL certificate checker, subnet calculator, email verifier, package tracker, proxy checker, speed test, CORS header generator, HTTP status checker, website down checker, email auth (SPF/DKIM/DMARC), URL metadata extractor, user-agent parser, domain age checker, and API tester.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. The 16 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.