Why will one website not load when everything else works?

How to tell in two minutes whether a site is down for everyone or only for you, and the handful of local causes when it is only you.

Difficulty: beginner
Time: 15 min
Read: 3 min

Short answer

First establish whether it is you or them: try the site on mobile data with wifi off. If it fails there too, the site is down and there is nothing to fix. If it works, the problem is local — usually a cached page, a browser extension, a security tool or your DNS.

The instinct is to restart the router, which is almost never the answer when everything else on the internet is working. Splitting 'them' from 'you' first saves the whole exercise.

Step by step

Try the same address on a different network.Phone with wifi turned off is the quickest test. Failing on both your broadband and mobile data means the site itself is down.
Try a different browser, or a private window.A private window disables most extensions and ignores stored data. If the site works there, the cause is something stored in your normal browser.
Clear the cached copy of that page.A forced reload — holding shift while clicking reload on a computer — fetches a fresh copy rather than the stale one. This fixes a surprising number of half-broken pages.
Clear cookies for that one site rather than everything.Most browsers let you clear data for a single site from the padlock or information icon in the address bar. It signs you out of that site only, which is far less disruptive than clearing everything.
Disable extensions one at a time.Ad blockers, privacy tools and password managers all break individual sites occasionally. Turn off the most likely one and retry before disabling everything.
Check anything filtering your connection.A VPN, a security suite, parental controls on the router, or a work profile can block one site while everything else works. Turn a VPN off and retry as a test.
Try a different DNS as a test.DNS translates a site's name into an address. If your provider's DNS has a stale or broken entry, one site fails while others work. Switching a device to a well-known public DNS temporarily confirms it.
Check the address itself.A typo, an old bookmark to a page that has moved, or an http address on a site that now requires https. Type the domain fresh rather than using the saved link.

Tips

If a site loads but looks broken — no styling, missing images — that is nearly always a cached copy. Force a reload before anything else.
Note whether other people in the house can reach it. One device failing narrows the problem enormously.
Downdetector-style status sites are useful, but the mobile data test is faster and more reliable.

Common mistakes

Restarting the router — If every other site works, the router is proven fine. This wastes ten minutes and knocks the rest of the household offline.
Clearing all browsing data to fix one site — It signs you out of everything and loses saved preferences across every site, when clearing data for the single site would have done the same job.

If it doesn't work

Site loads on the phone but not the laptop

Cause: Browser data, an extension or a security tool on the laptop — Fix: Try a private window first, then clear that site's data, then disable extensions in turn.

Security warning about the certificate

Cause: Usually a wrong clock on the device, sometimes a filtering tool intercepting traffic — Fix: Check the date and time are correct and set automatically. Never click through a certificate warning on a site where you sign in.

Site works on mobile data but not on home broadband

Cause: A DNS problem, or a block applied at the router — Fix: Check any parental control or content filter on the router, then test with an alternative DNS on one device.

Page loads endlessly and never finishes

Cause: One element of the page being blocked, often by an ad blocker or privacy extension — Fix: Disable the blocker for that site only rather than turning it off entirely.

Questions people ask

Is it safe to change my DNS?

Changing to a well-known, reputable public DNS service is a normal thing to do and reversible. Do not use a DNS server recommended in an unsolicited message or a random forum post — a hostile DNS can redirect you to fake sites.

The site says my browser is unsupported. What now?

Update the browser. An outdated browser is also the biggest single security risk on a computer, so this is worth doing regardless of the site.