Diagnostics
11 tools in this category. 1 run entirely on your device; 10 make network requests, and each one names the hosts it talks to.
What is in this category
Section titled “What is in this category”| Tool | What it does | Leaves your device |
|---|---|---|
| Network Tester | Test RTT, throughput, and connectivity to user-defined endpoints | yes: the URL you enter, cloudflare-dns.com, dns.google, dns.quad9.net, doh.opendns.com, dns.adguard-dns.com |
| DNS Tools | DNS over HTTPS client with multiple provider support and caching | yes: cloudflare-dns.com, dns.google, dns.quad9.net, doh.opendns.com, dns.adguard-dns.com |
| Ping & Traceroute | Test network connectivity and trace packet paths to destinations | yes: the host you enter |
| Port Scanner | Scan network hosts for open ports and running services | yes: the host you enter |
| SSL/TLS Checker | Analyze SSL certificates, expiry dates, and TLS configuration | yes: the hostname you enter, api.certspotter.com |
| WHOIS Lookup | Look up domain registration and IP block ownership information | yes: rdap.org, the registry or RIR RDAP server rdap.org redirects to |
| Email Diagnostics | Check MX records, SPF, DKIM, and DMARC configurations | yes: cloudflare-dns.com, dns.google |
| HTTP Headers | Analyze HTTP response headers and security configuration | yes: api.hackertarget.com |
| Security Headers | Analyze HTTP security headers and get recommendations | yes: api.hackertarget.com, observatory-api.mdn.mozilla.net |
| Redirect Checker | Trace HTTP redirect chains and analyze URL redirections | yes: api.hackertarget.com |
| User Agent Parser | Parse and analyze browser user agent strings | no |
10 of 11 rows leave your device, so those are the only ones that stop working offline. The hosts in that column come from the tool registry, not from this page, so they cannot drift from what the code actually requests. 4 tools here gain capabilities in the desktop build that a browser cannot provide at all; see the per-tool notes below and how the diagnostics work for the mechanism.
Tool by tool
Section titled “Tool by tool”Network Tester
Section titled “Network Tester”Test RTT, throughput, and connectivity to user-defined endpoints. Open it at /tools/network-tester/.
- RTT measurement
- Throughput tests
- CORS-constrained
Sends requests to the URL you enter, cloudflare-dns.com, dns.google, dns.quad9.net, doh.opendns.com, dns.adguard-dns.com. Desktop build only: real ICMP ping. In a browser these fall back to what the web platform permits, which is less.
DNS Tools
Section titled “DNS Tools”DNS over HTTPS client with multiple provider support and caching. Open it at /tools/dns-tools/.
- DoH support
- Multiple providers
- DNSSEC validation
Sends requests to cloudflare-dns.com, dns.google, dns.quad9.net, doh.opendns.com, dns.adguard-dns.com. Desktop build only: direct DNS queries. In a browser these fall back to what the web platform permits, which is less.
Ping & Traceroute
Section titled “Ping & Traceroute”Test network connectivity and trace packet paths to destinations. Open it at /tools/ping-traceroute/.
- Connectivity tests
- Path tracing
- Latency measurement
Sends requests to the host you enter. Desktop build only: real ICMP ping, system traceroute, local network interface enumeration. In a browser these fall back to what the web platform permits, which is less.
Port Scanner
Section titled “Port Scanner”Scan network hosts for open ports and running services. Open it at /tools/port-scanner/.
- Common ports
- Custom ranges
- Port name lookup
Sends requests to the host you enter. Desktop build only: real TCP connect scanning. In a browser these fall back to what the web platform permits, which is less.
SSL/TLS Checker
Section titled “SSL/TLS Checker”Analyze SSL certificates, expiry dates, and TLS configuration. Open it at /tools/ssl-checker/.
- Certificate info
- Expiry check
- Chain validation
Sends requests to the hostname you enter, api.certspotter.com.
WHOIS Lookup
Section titled “WHOIS Lookup”Look up domain registration and IP block ownership information. Open it at /tools/whois-lookup/.
- Domain info
- IP ownership
- Registrar data
Sends requests to rdap.org, the registry or RIR RDAP server rdap.org redirects to.
Email Diagnostics
Section titled “Email Diagnostics”Check MX records, SPF, DKIM, and DMARC configurations. Open it at /tools/email-diagnostics/.
- MX records
- SPF/DKIM/DMARC
- Deliverability
Sends requests to cloudflare-dns.com, dns.google.
HTTP Headers Analyzer
Section titled “HTTP Headers Analyzer”Analyze HTTP response headers and security configuration. Open it at /tools/http-headers/.
- Header analysis
- Security score
- Category sorting
Sends requests to api.hackertarget.com.
Security Headers Checker
Section titled “Security Headers Checker”Analyze HTTP security headers and get recommendations. Open it at /tools/security-headers/.
- HSTS check
- CSP analysis
- Security grade
Sends requests to api.hackertarget.com, observatory-api.mdn.mozilla.net.
Redirect Checker
Section titled “Redirect Checker”Trace HTTP redirect chains and analyze URL redirections. Open it at /tools/redirect-checker/.
- Redirect chain
- HTTPS upgrade
- Loop detection
Sends requests to api.hackertarget.com.
User Agent Parser
Section titled “User Agent Parser”Parse and analyze browser user agent strings. Open it at /tools/user-agent-parser/.
- Browser detection
- OS detection
- Device type
Runs entirely on your device; no request is made.
How this page is produced
Section titled “How this page is produced”Everything above is generated at docs build time from lib/tool-registry.ts. Editing this page by hand does nothing, because the next build overwrites it. Fix the registry instead.