How to read the output
- Ping prints one line per reply with its round-trip time (
time=12.4 ms) and ends with the packet loss and the minimum, average and maximum. Four replies with similar times and 0% loss is a healthy path. - Traceroute lists the routers between our server and the target, one per line. The times grow with distance; a jump of tens of milliseconds between two hops is usually a long cable, such as a sea crossing.
* * *is a router that does not answer probes — common, and harmless when later hops answer. - MTR sends five rounds to every hop and prints a table. The column to read first is
Loss%on the last line: that is the loss your traffic sees. Loss on a middle hop that does not carry on to the end is that router declining to answer.
| Column | Meaning |
|---|---|
| Loss% | Probes to this hop that got no answer |
| Snt | Probes sent |
| Last / Avg | The last and the average round trip, in milliseconds |
| Best / Wrst | The fastest and the slowest round trip |
| StDev | How much the round trips vary — high values mean jitter |
Measuring the way back
Routes on the internet are often asymmetric: the packets from our server to you can take other networks than yours to it. For the other direction, run MTR or pathping from your own machine against the test address listed under the tool — a longer run catches what one round of probes misses.
mtr -rwbc 50 45.153.34.90
mtr -6 -rwbc 50 2a0f:ca80:b00b:d657::5pathping 45.153.34.90For throughput, fetch a test file and let curl print the rate in bytes per second — multiply by eight for bits. --max-time stops it after fifteen seconds, whatever the file’s size.
curl -o /dev/null --max-time 15 \
-w '%{speed_download} B/s\n' \
https://45.153.34.90/files/100MB.binWhere the tests run
Every test on this page runs on our test server on the TechTies network (AS197170). What you see is the route from there at the moment you run it: it changes when networks change their routing, and a single run can catch a busy minute. If you are choosing between our two locations, they are close neighbours for most of Europe: Frankfurt or Amsterdam shows how to compare them for your own users. There is no test server in Frankfurt yet.
Frequently asked
What is a looking glass?
A page where a network lets anyone run ping, traceroute or MTR from its own servers. It shows how that network reaches the rest of the internet — the routers on the way, the round-trip time and any packet loss — without an account or a server there. Hosting providers publish one so that customers can check the route to their own location before they order.
Should I test from here to my IP, or from my side to your test address?
Both, because internet routes are often asymmetric: the way back can take other networks than the way there. The test above shows the path from Amsterdam to you; ping or mtr from your own machine to our test address, 45.153.34.90, shows the path you send on. A problem that shows up in both directions is usually close to one of the two ends.
Why do some hops show * * * or packet loss?
Many routers do not answer traceroute probes, or answer them only when they have nothing else to do. Loss at one hop while every hop after it is clean is a router that is slow to answer, not traffic being lost; loss that starts at one hop and carries on to the end is real.
Why does my own IP not answer ping?
Home routers and many firewalls drop ping requests (ICMP echo) by default, so 100% loss to your own address is normal and says nothing about your connection. Traceroute and MTR still show the path up to the last router that answers, which is usually your provider's.
Is there a limit?
Five tests a minute and fifty a day for each address, one at a time, each stopped after 30 seconds. Private, reserved and our own network's addresses cannot be tested; a host name is resolved once, and every address it resolves to has to be public.
Related guides
Frankfurt or Amsterdam: picking a European server location
How to measure latency properly instead of guessing, what genuinely separates the two European hubs, and the three cases where the choice changes anything.
Cloudflare error 522: connection timed out — find what drops Cloudflare at your origin
Error 522 means Cloudflare got no answer from your server within 19 seconds. Find the cause at the origin: firewall, wrong DNS IP, fail2ban bans or overload.