UD5 Toolkit
Default Wi‑Fi Password Calculator - Online ISP Router Keygen
Enter a router's MAC address or serial and generate the common default WPA passphrase for major ISP brands. Educational purpose only.
Network Tools - Diagnosis & Lookup
54+ toolsDNS Record Lookup - Online Query A, AAAA, MX, TXT
Query DNS records for any domain directly from your browser using DNS-over-HTTPS. See A, AAAA, MX, CNAME, and TXT. No logs.
SSL Certificate Checker - Online Verify Expiry & Chain
Enter a domain and see its SSL certificate details: issuer, validity dates, and chain. Client‑side fetch.
URL Redirect Chain Tracer - Online Check Hops
Enter a URL and follow every redirect until the final destination. Shows each hop's status code, location, and duration.
Subnetting Practice Quiz - Online CIDR & IP Drills
Randomly generated subnetting questions. Calculate network address, broadcast, and usable range. For CCNA prep.
Security Headers Auditor - Online Check HSTS, CSP & More
Enter a website and check which security headers (HSTS, CSP, X‑Frame‑Options) are present. Get a security grade.
CORS Header Debugger - Online Check Cross‑Origin Access
Enter a URL and see its CORS headers. Understand why a fetch fails. Check preflight responses. Client‑side debugger.
WHOIS Domain Lookup - Online Ownership & Expiration Check
Check WHOIS information for any domain: registrar, expiration date, and name servers. Quick and private using public WHOIS data aggregators.
SSL Cipher Suite Checker - Online Test TLS Security
Check which cipher suites a website supports and identify weak or outdated ones. Quick security audit from your browser.
Redirect Rule Tester - Online See How Browsers Follow
Enter a URL and see the full redirect chain with status codes and response times. Also validates against your chosen rule.
TCP State Machine Visualizer - Online Animated Diagram
Click through the TCP connection states (LISTEN, SYN_SENT, ESTABLISHED…) and see the animated transitions. Networking education.
Online Ping Test - Measure Latency to Servers
Send HEAD requests to popular websites and measure the round‑trip time. Quick network health check. Client‑side.
Connection Speed Estimator - Online Download Test
Quickly estimate your internet connection speed by downloading a small test file. See class and recommendations.
Local Peer‑to‑Peer Chat - Online No‑Server Messenger
Create a temporary chat room between two browser tabs or devices on the same network using WebRTC data channels. Copy the code.
Traceroute Simulator - Online Visual Hop Path
Simulate a traceroute by entering a destination IP. Learn about AS paths and latency. Does not send real packets; educational visualisation.
DNSSEC Chain Validator - Online Check RRSIG & DS
Validate a DNSSEC chain by entering DS and RRSIG records. Verify that signatures match. Educational. Local algorithm.
ETag & Last‑Modified Validator - Online Check Cache Headers
Send conditional requests to a URL and verify that the server correctly handles ETag and If‑None‑Match. Audit caching.
CORS Proxy Emulator - Online Test Cross‑Origin Requests
Bypass CORS for testing by routing requests through a local service worker proxy. Debug APIs without server changes. Experimental.
DNS Propagation Checker - Online Verify Record Status
Query a domain's DNS record against multiple public resolvers (Google, Cloudflare) and see how it propagates. Client‑side fetch.
Wi‑Fi QR Code Generator (Advanced) - Online WPA3 & Hidden
Generate a Wi‑Fi QR code with full options: WPA3, hidden network, and EAP. Download as SVG. All local.
WebRTC Text Chat (P2P) - Online No‑Server Messenger
Establish a peer‑to‑peer text chat between two browser tabs or devices using WebRTC data channels. All signaling via copy‑paste. No server.
DNS Record Syntax Checker - Online Validate BEFORE Publishing
Paste any DNS record and check if its format is valid for the selected record type (A, AAAA, CNAME, MX, TXT, SRV). Prevents typos.
CAA Record Generator - Online DNS Certification Authority
Create a CAA DNS record to specify which certificate authorities can issue SSL certs for your domain. Prevent mis‑issuance.
BIMI Record Generator - Online Brand Logo for Email
Generate a BIMI record to display your verified brand logo in email clients. Includes SVG logo URL and VMC certificate path.
EventSource Polyfill Demo - Online See SSE with Custom Headers
Demonstrate how to add custom headers and POST‑like functionality to EventSource using a polyfill. Code and example.
Network Throttle Simulator - Online Slow 3G & Offline Test
Test how your page loads under slow, 3G, or offline conditions by intercepting fetch and applying delays. No DevTools needed.
DMARC Record Generator - Online Email Policy Builder
Create a DMARC policy record with percentage, reporting addresses, and alignment mode. Validate and copy the final DNS TXT.
WebSocket Load Tester - Online Simulate Many Clients
Open many parallel WebSocket connections and send messages. Test your server's concurrency. All from your browser.
Email Header Analyzer - Online SPF, DKIM, DMARC Check
Paste raw email headers and see authentication results (SPF, DKIM, DMARC) in a readable table. Find spoofing attempts.
WebTransport Echo Client - Online QUIC Test
Connect to a WebTransport server and exchange data over QUIC. See latency and throughput. Perfect for exploring low‑latency real‑time APIs.
HSTS Header Checker - Online Strict‑Transport‑Security
Fetch a site’s HSTS header and validate its syntax, max‑age, and subdomain flags. Ensure your site enforce HTTPS.
Network Information API Checker - Online Downlink Speed
Display your effective connection type (4g, 3g, etc.) and downlink speed using the Navigator API. Adapt your app accordingly.
WebSocket Test Client - Online Connect & Send Messages
Connect to a WebSocket endpoint, send messages, and view the stream of received data. Perfect for debugging real‑time apps.
SSE (EventSource) Tester - Online Stream Listener
Connect to an SSE endpoint and display events in real time. Inspect event types and data. Handy for frontend devs.
DKIM Record Generator - Online Public Key DNS Entry
Generate a DKIM DNS record from a public key and selector. Check syntax. Improve your domain’s email deliverability.
SPF Record Generator - Online Email Authentication DNS
Build a valid SPF TXT record by selecting mail servers, IPv4/IPv6 ranges, and includes. Validate syntax and get ready‑to‑publish output.
API Status Checker - Online Test Endpoint & Response
Enter an API URL and quickly check its HTTP status code and response time. See response headers and body. Browser fetch.
Bandwidth & Download Time Calculator - Online
Estimate how long it takes to download/upload a file given bandwidth speed. Also convert between bits and bytes.
IPv4 Subnet Builder - Online Visual Range Calculator
Enter an IP and CIDR prefix to visually see network address, broadcast, usable range, and subnet mask conversions.
Browser Speed Test - Online Measure Download/Upload
Measure your internet connection speed by downloading and uploading a small test file. Works from your browser.
TCP/UDP Port List - Online Common Service Reference
Searchable table of well‑known TCP and UDP ports with their services. Check 80, 443, 3306, and many more.
Ethernet Cable Color Code - Online RJ45 T568A/B Wiring
Interactive guide to crimping RJ45 connectors. See the wire order for T568A/B standards. Helpful for DIY network cables.
What Are My DNS Servers - Online Detect via Browser
Attempt to detect your current DNS resolver IPs using DNS‑leak test queries. Educational. Privacy‑friendly.
What Is My IP Address - Online IP Lookup & Info Tool
Find your public IP address and view approximate geolocation, ISP, and browser header details. No personal data stored. Static and instant.
WHOIS Lookup - Online Domain Ownership & Expiration Check
Check WHOIS information for any domain: registrar, expiration date, and name servers. Quick and private using public WHOIS data aggregators.
Random MAC Address Generator - Online Hardware Test IDs
Generate valid, random unicast MAC addresses for testing or spoofing. Select OUI prefix if desired. Local only.
Data Transfer Rate Converter - Online Mbps Gbps & KiB/s
Convert network and data transfer speeds: bps, Kbps, Mbps, Gbps, KiB/s, MiB/s. A must when comparing internet plans. Fast and local.
URL Shortener Decoder - Online Expand Shortened Links
Find out the real destination of any shortened link (bit.ly, t.co, etc.) without clicking. Resolves redirects locally using public HTTP headers.
DNS Lookup - Online Domain Records Checker (A, MX, CNAME)
Query DNS records for any domain directly from your browser using DNS-over-HTTPS. See A, AAAA, MX, CNAME, and TXT records. No logs.
HTTP Headers Checker - Online Inspect URL Response Headers
Enter a URL and see the full HTTP response headers returned by the server. Detect redirects and server type. Useful for SEO and web debugging.
Is It Down or Just Me - Online Website Uptime Checker
Check if a website is globally reachable or experiencing issues. Status code and latency displayed. Quick browser-side test.
SSL Certificate Checker - Online TLS Expiry & Info Tool
Inspect any website's SSL/TLS certificate details: issuer, expiry date, subject, and SANs. Verify certificate chains. All checks are private and require no server upload.
Wi‑Fi QR Code Generator - Online Join Network Scan
Create a QR code that lets people connect to your Wi‑Fi without typing a password. Just scan and join. Secure local.
Email Header Parser - Online Analyze Email Delivery Path
Paste raw email headers and get a human-readable breakdown of the delivery route, authentication results, and delays. Private analysis.