A complete guide to how the Ping Tool works, why real ICMP ping isn't possible in a browser, and how to interpret its results.
Launch the Ping Tool →The Ping Tool lets you test whether a host — a domain name or an IP address — is reachable, and measure how long round-trip responses take. You type in a hostname or IP, choose how many probes to send (4, 8, 16, 32, or continuous mode), and the tool fires off a sequence of timed requests, displaying each result in a scrolling console view that looks and reads similarly to the output of a traditional command-line ping utility.
Results are color-coded: successful replies are shown in a bright accent color with the measured round-trip time in milliseconds, while timeouts are shown in red. A running summary panel tracks packets sent, packets received, percentage loss, and average round-trip time, and a final statistics line reports the minimum, average, and maximum response times once the sequence finishes.
A continuous mode is also available for ongoing monitoring, with a Start and Stop button pair instead of a single Ping button, so you can watch a host's responsiveness over an extended period rather than a fixed number of probes.
The single most important thing to understand about this tool, and about literally every browser-based "ping" tool on the internet, is that it is not sending real ICMP Echo Request packets, which is what the traditional ping command on Windows, macOS, or Linux actually does. The tool says this directly in its own on-page disclaimer, rather than letting users assume it works identically to the command-line tool of the same name.
ICMP (Internet Control Message Protocol) operates at a low level of the networking stack, below the HTTP and TCP connections that web pages are built from. Constructing and sending a raw ICMP packet requires operating-system-level network socket access, which is a deliberate security boundary that web browsers do not cross. If JavaScript running on any arbitrary website could send raw network packets of its choosing, that would open the door to serious abuse: scripts could be used to scan internal networks, probe for vulnerable devices, or launch denial-of-service traffic, all without the user's knowledge, simply by visiting a malicious page. Browser vendors have never exposed this capability, and there is no realistic path for them to start doing so for ordinary web pages.
Because of that hard boundary, every browser-based "ping" tool, including this one, has to approximate connectivity testing using a mechanism that browsers do allow: an HTTP request. This tool works by firing a fetch() request to https://<host>/favicon.ico with a cache-busting query parameter appended, using the special no-cors request mode, and precisely timing how long the browser takes to either complete or time out that request using the high-resolution performance.now() timer.
The no-cors mode is a deliberate choice. A normal cross-origin fetch would be blocked by the browser's CORS policy unless the target server explicitly allows it, which almost no server does for a `favicon.ico` request from an arbitrary origin. Using no-cors mode tells the browser "I don't need to read the response content, I only need to know whether the request completed," which sidesteps the CORS restriction for this specific limited purpose. The tool never reads or needs the actual favicon image content; it only needs the timing of success versus timeout.
The choice of /favicon.ico as the target path is practical rather than arbitrary. Favicon files are present on the overwhelming majority of real-world websites, are typically very small (often only a few kilobytes), and sit at a well-known, predictable path that does not require guessing at a site's actual page structure. Requesting a small, nearly universal resource keeps the timing measurement close to pure network latency rather than being skewed by the time needed to download a large page or asset.
It is worth being honest about a limitation this introduces: if a target host does not have a favicon.ico file at all, or blocks requests to that specific path for some reason, the measured timing can still reflect a connection being established and a response (even a 404 Not Found) being returned, since the no-cors mode considers the request "complete" once any response arrives, not only on a successful HTTP 200 status. In the overwhelming majority of real-world tests, this produces a timing result that closely tracks actual network reachability and latency, which is why it works well as a close, real-world approximation despite not being a literal ICMP ping.
When you ping a domain name like example.com, each reply line in the console shows the format Reply from example.com (93.184.216.34): seq=1 time=42.1ms, with the resolved IP address displayed in parentheses right after the hostname — closely mirroring the familiar format of traditional command-line ping output.
Getting that IP address required solving a genuine technical gap. The favicon-timing mechanism described above uses fetch() with no-cors mode, and the browser does perform a real DNS lookup internally as part of completing that request — but critically, no-cors mode deliberately blocks JavaScript from reading almost any information about the response, including which IP address the browser actually connected to. There is no browser API that exposes "what IP address did this specific fetch resolve to and connect to."
To work around this, the tool performs a separate, explicit DNS lookup before starting the ping sequence, using the same DNS-over-HTTPS (DoH) technique proven out on this site's DNS Propagation Tool and NSLookup Tool. It sends a request to Cloudflare's DoH JSON endpoint (cloudflare-dns.com/dns-query) asking for the A record of the hostname you entered, and falls back to Google's equivalent DoH endpoint (dns.google/resolve) if the Cloudflare request fails for any reason. This lookup happens once per ping session, not once per individual probe, both to avoid unnecessary extra network traffic and because the resolved IP address for a given hostname essentially never changes meaningfully over the course of a single short ping run.
If you enter a raw IP address instead of a hostname, there is nothing to resolve, so the tool simply displays that same IP address in parentheses for consistent formatting across both cases, rather than showing the parenthetical only sometimes. If DNS resolution fails for any reason (an unusual hostname, a temporary resolver issue, or a host that genuinely does not have a public DNS record), the ping sequence still proceeds normally using the hostname directly for the actual timing requests; the tool simply omits the parenthetical IP rather than blocking the entire feature on a failed lookup.
Pinging cloudflare.com four times might produce: Pinging cloudflare.com (104.16.132.229)... followed by four reply lines each showing the same resolved IP, individual timings like time=18.3ms, and a final summary such as 4 probes sent, 4 received, 0% loss along with a round-trip min/avg/max line.
example.com) or an IPv4 address (like 8.8.8.8) into the input field.Consistently low, stable response times (typically under 50 milliseconds for well-connected hosts on the same continent, though this varies enormously by actual network path) generally indicate a healthy, responsive connection. Occasional timeouts mixed in with otherwise successful replies can indicate transient network congestion, a server under heavy load, or a connection being intermittently filtered.
A complete string of timeouts most often means one of three things: the hostname does not resolve to anything reachable, the target server is down or unreachable from your network, or the server is actively blocking requests that look automated or unusual (some servers rate-limit or block rapid repeated requests to the same resource, which could affect a tight continuous-mode loop against a sensitive target).
Because this tool measures HTTP-layer timing rather than raw ICMP, it is possible for a host to appear unreachable here while still responding to a true ICMP ping, and vice versa — some servers and firewalls are configured to respond to one protocol but not the other. This tool is best understood as a practical approximation of real-world web reachability and latency, which is often exactly what matters when you're trying to find out whether a website or web-facing service is responsive, rather than testing low-level network connectivity in isolation.
Consistently low, stable response times (typically under 50 milliseconds for well-connected hosts on the same continent, though this varies enormously by actual network path) generally indicate a healthy, responsive connection. Occasional timeouts mixed in with otherwise successful replies can indicate transient network congestion, a server under heavy load, or a connection being intermittently filtered.
A complete string of timeouts most often means one of three things: the hostname does not resolve to anything reachable, the target server is down or unreachable from your network, or the server is actively blocking requests that look automated or unusual (some servers rate-limit or block rapid repeated requests to the same resource, which could affect a tight continuous-mode loop against a sensitive target).
Because this tool measures HTTP-layer timing rather than raw ICMP, it is possible for a host to appear unreachable here while still responding to a true ICMP ping, and vice versa — some servers and firewalls are configured to respond to one protocol but not the other. This tool is best understood as a practical approximation of real-world web reachability and latency, which is often exactly what matters when you're trying to find out whether a website or web-facing service is responsive, rather than testing low-level network connectivity in isolation.
It's also worth noting what this tool cannot tell you: it cannot distinguish between "the server is down," "a firewall between you and the server is blocking the request," and "your own network connection has a problem," since all three produce the same observable symptom — a timeout. For deeper diagnosis of exactly where a connection is failing, a traditional traceroute utility (which this browser environment cannot replicate for the same raw-socket reasons ICMP ping cannot be replicated) would be the appropriate next step on a desktop system with full network access.
Command Prompt's ping sends real ICMP packets, which travel a different path through network equipment than HTTP requests and are processed differently by routers, firewalls, and the destination server. The two methods frequently report similar but not identical timings, and in some cases one will succeed while the other is blocked.
You can enter a private IP address, but the request will only succeed if your browser can actually reach that address over HTTP on port 443 (HTTPS) — most home routers and internal devices either don't run a web server on that exact port or will reject the request, so this tool is best suited to testing public, internet-facing hosts rather than internal network diagnostics.
The console view keeps a maximum of 500 recent lines to avoid consuming excessive memory in a long-running session; older lines are automatically removed as new ones are added, which keeps the tool responsive even during extended continuous monitoring.
In most cases, yes. The timing mechanism considers the request complete once any response is received, including a 404 Not Found, so the absence of an actual favicon image generally does not prevent a meaningful timing measurement.