Some websites open, but others are blocked on the same Wi-Fi

This usually is not weak Wi-Fi. If the exact same URL opens on mobile data but not on home Wi-Fi, the useful question is where the failure follows: the network, one device, one browser, or the website itself.

Do not change DNS, disable security software, or reset the router yet. A four-test split usually identifies the right branch first.

Use one exact URL and test in this order:

1. Open the exact same URL on the same device using mobile data or another network.
2. Open the URL on a second device connected to the same Wi-Fi.
3. On the first device, try a private window and then a different browser.
4. Check whether the browser shows a name-resolution error, a timeout, an access-denied page, or a certificate warning. Those are different failures.

Open Terminal or PowerShell. Replace example.com with the blocked domain, not a full page URL:

nslookup example.com
Test-NetConnection example.com -Port 443

nslookup checks whether the device can turn the domain into an IP address. Test-NetConnection checks whether it can reach the normal HTTPS port.

• Every device on home Wi-Fi fails, but mobile data works: inspect router DNS, parental controls, Safe Browsing/web filters, ISP security features, or an upstream outage.
• Only one device fails: check that device’s proxy, VPN, security suite, custom DNS, and hosts file before touching the router.
• Only one browser fails: an extension, browser proxy, security profile, or corrupt browser state is more likely than the router.
• nslookup fails but port 443 works when tested by IP: DNS is the leading branch. Do not permanently change DNS on a managed network without permission.
• DNS works but port 443 fails on every home device: the router, ISP route, or site-side blocking is more likely.
• The browser shows a certificate warning: do not click through. Check the device clock and stop if work/school filtering or unknown security software may be intercepting HTTPS.

1. Restart the browser, then the affected device.
2. If only one Windows device has stale DNS results, run ipconfig /flushdns once and retry. This clears the device cache; it does not fix a router or ISP filter.
3. Disable only the suspect browser extension for one test, then turn it back on if it was not the cause.
4. On your own home router, review Security, Parental Controls, DNS, Safe Browsing, web filter, and ISP protection logs before changing a setting.
5. If the router uses a custom DNS service, compare with the ISP default or a reputable resolver only on a network you manage. Record the old setting first.

Do not factory-reset the router before checking filters and DNS. A reset can wipe Wi-Fi names, ISP settings, port rules, and parental controls without proving what caused the block.

If you ask for help, send the browser error text, whether the site works on mobile data, whether another device on the same Wi-Fi fails too, and the router filter/DNS/security page with passwords, public IPs, account names, and Wi-Fi keys hidden.

Stop here if the site is controlled by work or school policy, the router admin page asks for credentials you should not share, the browser error mentions certificate interception, security software you do not recognize appears in the path, or the site is a bank, government, health, or work login page where bypassing filters may create account/security trouble.

Related Price2Click guide: /fix-home-wifi/

Official command references: nslookup and ipconfig.