What's happening?

Choosing an option runs about 15 seconds of automatic checks from your browser (uses roughly 15 MB of data at most).

What the troubleshooter checks

Six checks run in order: whether your device reports a connection, whether our server is reachable, whether a public DNS resolver answers, latency and jitter over 10 probes, IPv4/IPv6 availability and a 4-second download check. The results are combined with the problem you picked to produce the advice.

CheckWhat it tells you
Device statusWhether the operating system sees any network at all.
Internet reachabilityWhether traffic leaves your network and comes back.
Public DNSWhether names can be resolved. We query Cloudflare's public resolver, which is not necessarily the DNS your device uses.
Latency and stabilityMedian ping, jitter and timeouts to the nearest test server.
IPv4 / IPv6Which internet protocols your connection supports.
Quick downloadA rough speed indication. It is shorter than the full speed test and reads lower on fast connections.

What a browser can't check

For privacy reasons, websites can't see your Wi-Fi signal strength, router settings, cable faults or other devices on your network. The checks show symptoms from this device's point of view; the advice fills the gap with the most common causes for the problem you picked.

If the checks look healthy but the problem persists, it's likely intermittent. Run the 60-second ping test while it's happening, or keep a test history to show your ISP.

A troubleshooting order that saves time

  1. One device or all? If only one device is affected, fix the device (restart, forget the network, disable VPN).
  2. Wi-Fi or line? Test next to the router or on a cable. If the cable is fine, the problem is Wi-Fi (improve Wi-Fi).
  3. Always or at certain times? Slow only in the evening points to ISP congestion; test at different times.
  4. Restart the router once — unplug for 30 seconds.
  5. Contact your ISP with your results if the problem is on a cable, at all times, on all devices.

Questions

Does the troubleshooter change any settings?

No. It only measures from your browser and suggests steps. Nothing on your device or router is changed.

How much data does it use?

Up to about 15 MB, almost all of it in the 4-second download check. The other checks use a few kilobytes.

Why does it say my connection is healthy when it isn't?

Many problems are intermittent or limited to one service. If the checks pass, run a longer ping test while the problem is happening, and check the affected service's status.