Online Traceroute Test
Trace the network path from locations around the world to any server. This free online traceroute shows every router hop between the test location and your host, with latency and packet loss for each hop.
At a glance
- ICMP traceroute: echo requests with increasing TTL, 4 probes per hop, 2-second timeout per probe.
- Per hop: host name (reverse DNS), IP address, minimum, average and maximum latency, packet loss and each probe's round-trip time.
- Up to 64 hops: 30 by default.
- Multiple locations: run the same trace from up to 3 locations at once without an account.
- Source IP shown: see which public address each location traces from, for firewall allow-lists.
- Free: no sign-up; export results as PDF, CSV or JSON.
How to run an online traceroute
- Enter a host name (such as
www.example.com) or an IPv4 address. - Optionally change the maximum number of hops (1 to 64).
- Select up to three locations.
- Click Run Test. Each location traces the route and shows the hop table.
How traceroute works
Traceroute sends packets with a time-to-live (TTL) of 1, 2, 3 and so on. Each router along the path decrements the TTL, and the router where it reaches zero discards the packet and replies. That reply reveals the router's address and the round-trip time to it. Repeating this with growing TTL values maps the whole path until the destination answers. Dotcom-Tools sends four ICMP echo probes per hop and stops at the first hop where the target replies.
How to read traceroute results
- Latency that rises and stays high: the delay starts at that hop. A jump between two hops in different cities or countries is normal (distance); a jump within one network may mean congestion.
- Latency that spikes at one hop but drops again later: that router deprioritizes replies to traceroute. It is not a problem for real traffic.
- **Asterisks (
*) or 100% loss on a hop:** the router didn't answer. Many routers block or rate-limit ICMP, so this is only a problem if all following hops are silent too. - The trace never reaches the target: traffic is blocked or lost after the last responding hop. Check the firewall on the target and the network that owns that hop.
Why trace from multiple locations?
A traceroute from your own computer only shows one path. Running it from several locations at once shows whether a problem is on the server's side (every path is slow near the end) or on one network route (only one location is affected). It also shows which networks and countries your traffic crosses to reach each region.
Traceroute vs. ping
The Ping Test tells you whether a host answers and how fast, end to end. Traceroute tells you where along the path latency and packet loss appear. Start with ping; use traceroute when ping shows high latency or loss.
Related free tools
- Ping Test: reachability and average latency from multiple locations.
- Web Server Test: check if the web server itself responds and how fast.
- China Firewall Test: check whether your site loads from inside mainland China.
To monitor network paths and latency continuously with alerts, see Dotcom-Monitor.
Frequently asked questions
What is a traceroute test?
A traceroute test maps the path packets take from one computer to another and measures the latency to each router (hop) along the way. It is used to find where network delays, packet loss or outages occur.
What does an asterisk mean in traceroute?
An asterisk means the probe got no reply within the timeout, two seconds here. Many routers ignore traceroute probes on purpose, so asterisks on a middle hop are normal if later hops still answer.
Is this traceroute ICMP or UDP?
ICMP. It sends ICMP echo requests with increasing TTL, like the Windows tracert command. Linux traceroute uses UDP by default, so a few routers may answer differently.
Can I traceroute an IPv6 address?
Not yet. The online traceroute supports host names and IPv4 addresses.
Why does traceroute show high latency at a hop when my site is fast?
Routers handle traceroute replies with low priority. If latency is high at one hop but lower at the hops after it, the router is simply slow to reply, not slow to forward traffic.
How many hops does the traceroute check?
Up to 30 by default, adjustable from 1 to 64. The trace stops as soon as the target answers.
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