Network Toolkit

Checking protocol…

Extended test runs multiple requests to see if the browser upgrades from HTTP/2 to HTTP/3 after Alt-Svc is learned.

Result

Name

Type

DNS server

DNS queries are executed from the Worker using DNS-over-HTTPS.

Result

Domain

Timeout (ms)

DNS server

DKIM selector (optional)

Resolve A/AAAA for MX hosts

Includes: MX, SPF (TXT) with parsed mechanisms + bounded include/redirect walk, DMARC, and optional DKIM.

Result

Public IPv4

Zone list

DNS server

DNSBL results vary by provider policy. This checks <reversed-ip>.<zone>. Use only for public IPs you own/control.

Result

Microsoft Safe Links URL (or wrapped URL)

Decodes the url parameter (percent-decoded up to 3 times).

Result

Download size

Upload size

Jitter samples

Measures throughput between your browser and this Worker (edge). Jitter is computed from repeated HTTP RTT samples.

Result

URL

Method

Redirects

Confirms HTTP(S) reachability from the Cloudflare edge with status, headers, redirects, and timing.

Result

Hostname (public)

Scan mode

Uses the public SSL Labs Assessment API to generate an SSL Labs-like report for a public hostname. Scans can take a while; the UI will poll until READY.

Result

SSL Labs can only assess publicly reachable hosts and is rate-limited.

Hostname or public IPv4

Ports (comma-separated)

Scheme

Path

Timeout (ms)

This is an HTTP(S) port probe from the Cloudflare edge (not a raw TCP SYN scan). Non-HTTP services may report as closed/unknown.

Result

URL (HTTP ping)

Samples

Measures edge → target HTTP timing (not ICMP).

Result

Target (hostname or IP)

Cloudflare Workers cannot run native traceroute. This tab calls /api/traceroute, which requires a backend API you control (TRACEROUTE_API_URL).

Result

IPv4 address

CIDR

Client-side calculator. No data leaves your browser for this tab.

Result

Client values from Cloudflare request context

Most important for QUIC is httpProtocol (look for h3).

Toolkits