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Why a website can be down for some people and not others

“It works for me” and “it is down for me” can both be true at the same time. A website is not one machine in one place, and the path between each visitor and the site is different.

The usual reasons

  • DNS differences. Different networks may have different cached answers. After a site moves, some people reach the new server and some still reach the old one. See DNS propagation.
  • CDN or regional servers. Large sites run many servers around the world. One region’s servers can fail while the rest are fine, so people in that region see errors.
  • Internet provider faults. A broken route between your provider and the site makes it unreachable only for that provider’s customers.
  • Blocking and geo-restrictions. A site may block certain countries, networks, VPNs or automated traffic. You get a 403 or a blank page while others do not.
  • Security software. A firewall, antivirus or parental filter on your network or device can block a site that is fine for everyone else.
  • Overload. A busy site may reject some requests and accept others, so it feels random.
  • Certificate or time problems. A wrong clock on your device makes secure sites fail. A certificate problem on only some servers affects only some visitors.

How to find out which one it is

  1. Run a check. If the regional probes show a mix of successes and failures, the problem is regional. Our regional map shows where the failures are.
  2. Try your phone on mobile data. If it works there, the problem is your network.
  3. Try a different DNS server and flush your DNS cache.
  4. Turn off any VPN, and test without extensions.

What it means for site owners

If visitors in one country report problems and your own tests are fine, check your CDN’s status page, your firewall rules, and any country blocks. Monitoring from several regions, as our worldwide check does, catches these problems that a single-location monitor misses.

Check a website now

Is it down for everyone, or just you? Paste an address and we test it from twelve places.

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Related guides

Last updated 2 November 2026. Written by the siteupdown.com team. Spotted a mistake?

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