How do you troubleshoot a home network methodically?

By working outward from the device to the internet, testing one layer at a time — because the symptom is almost always the same regardless of cause, and guessing wastes hours that a sequence resolves in minutes.

The sequence, in order:

Is it one device or all of them? This single question splits the problem in half. One device means the device; all devices means the network or the connection.

Is it one website or all of them? All sites failing points at connectivity or DNS; one site failing points at that site, or at something blocking it.

Wired or wireless? If a cabled device works and wireless does not, the problem is Wi-Fi rather than the internet — a distinction people conflate constantly.

Can you reach the router? Opening its admin page proves the local network is working, which separates "my network is broken" from "my internet is down".

Does the router show a connection? The status lights or admin page indicate whether the line is synced.

Is it the provider? Check a status page on mobile data, and check whether neighbours on the same provider are affected.

The specific tests worth knowing:

Try a site by IP address rather than name — if that works and names do not, it is DNS, which is one of the commonest causes and is fixed by changing resolver or restarting the router.

Try a different network, such as a phone hotspot, which immediately separates device from connection.

Try a different device on the same network.

Restart in order — modem or router first, wait for it to fully sync, then devices. Restarting everything simultaneously loses the information about which one fixed it.

What causes most real problems: Wi-Fi congestion and interference rather than the connection itself; distance and building fabric; an overloaded or ageing router; DNS; a device with a stale address or a misconfigured VPN; and provider faults, which are less common than assumed.

Record what you changed, since the commonest way a network stays broken is several changes made at once with none of them reversed.