Fix Can’t Access Certain Websites on Browser

If your browser won’t load certain websites while others work fine, the cause is usually a DNS issue, a corrupted cache, a proxy or VPN conflict, or a firewall rule—not a problem with the sites themselves. This guide walks you through the most effective fixes, from clearing your DNS cache to adjusting network settings, so you can get back online quickly.

Why Do Some Websites Fail to Load?

When you type a web address, your browser asks a DNS (Domain Name System) server to translate the human-friendly name (like example.com) into an IP address. If that translation fails, the browser shows an error such as “This site can’t be reached” or “ERR_NAME_NOT_RESOLVED.” Other common culprits include:

Corrupted browser cache or cookies – Old stored data can conflict with the current version of a site.
Proxy or VPN interference – A misconfigured proxy or VPN can block specific domains.
Firewall or antivirus overreach – Security software sometimes flags legitimate sites as threats.
MTU (Maximum Transmission Unit) issues – If your network’s MTU is set too high, some packets get dropped, causing certain sites to hang.
ISP-level blocks or DNS filtering – Your internet service provider might block certain domains, or its DNS servers might be temporarily down.

Quick Fixes to Try First

Before diving into deeper troubleshooting, try these simple steps—they resolve a surprising number of cases:

Restart your router and modem. Unplug them for 30 seconds, then plug back in. This clears temporary network glitches.
Use a different browser. If the site loads in another browser, the problem is likely browser-specific.
Try incognito/private mode. This disables extensions and uses a fresh session, helping you isolate whether an extension is the culprit.
Disable your VPN or proxy temporarily. If the site loads without them, adjust their settings.
Check if the site is down for everyone. Use a service like downforeveryoneorjustme.com (or a similar uptime checker) to see if the site is actually offline globally.

Flush Your DNS Cache

Your computer stores DNS lookup results locally to speed up browsing. If that cache becomes corrupted or outdated, you get errors for sites that are actually online. Flushing it forces your system to ask a DNS server for fresh information.

On Windows: Open Command Prompt as administrator and run ipconfig /flushdns.

On macOS: Open Terminal and run sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder (you’ll be prompted for your password).

On Linux: The command varies by distribution—try sudo systemd-resolve --flush-caches or sudo resolvectl flush-caches.

After flushing, restart your browser and try the site again.

Switch to a Public DNS Server

Your ISP’s DNS servers can be slow, unreliable, or even block certain domains. Switching to a public DNS provider often resolves access issues. Two well-known options are:

Cloudflare: Primary 1.1.1.1, Secondary 1.0.0.1
Google Public DNS: Primary 8.8.8.8, Secondary 8.8.4.4

How to change DNS on Windows: Go to Control Panel > Network and Internet > Network and Sharing Center > Change adapter settings. Right-click your active connection, select Properties, choose “Internet Protocol Version 4 (TCP/IPv4)”, and click Properties. Select “Use the following DNS server addresses” and enter the numbers above.

On macOS: System Settings > Network > your connection > Details > DNS. Click the + button and add the addresses.

On your router: Log into your router’s admin panel (usually 192.168.1.1 or 192.168.0.1) and look for DNS settings under WAN or Internet. This changes DNS for all devices on your network.

Clear Browser Cache and Cookies

Sometimes the problem isn’t DNS but your browser’s stored data. A corrupted cached version of the site or an old cookie can cause errors like “ERR_CONNECTION_RESET” or “500 Internal Server Error.”

In Chrome, click the three-dot menu > More tools > Clear browsing data. Choose a time range of “All time” and check “Cookies and other site data” and “Cached images and files.” Then click Clear data. In Firefox, go to Settings > Privacy & Security > Cookies and Site Data > Clear Data. In Edge, the process is nearly identical to Chrome.

If you don’t want to wipe everything, try just the site-specific data: open the site in a private window—if it works, then the issue is definitely stored data. You can also use your browser’s developer tools (F12) to clear only that site’s storage.

Disable Browser Extensions and Hardware Acceleration

Extensions can interfere with page loading, especially ad blockers, privacy tools, or VPN extensions. A quick test: disable all extensions and see if the site loads. If it does, re-enable them one by one to find the culprit.

Hardware acceleration—which uses your GPU to render pages—can also cause issues on some systems. To disable it in Chrome: Settings > System > turn off “Use hardware acceleration when available.” In Firefox: Settings > General > Performance > uncheck “Use recommended performance settings” and then uncheck “Use hardware acceleration when available.” Restart the browser afterward.

Adjust MTU Settings (Advanced)

If the site loads on your phone but not your computer, and you’ve tried everything else, an MTU mismatch might be the cause. MTU is the largest packet size your network can transmit. If it’s set too high, some packets get dropped, causing certain sites to hang or time out.

The default MTU for Ethernet is 1500 bytes. For PPPoE connections (common with DSL), it’s often 1492. To find the optimal value, you can run a ping test with the “don’t fragment” flag. On Windows, open Command Prompt and type ping -f -l 1472 8.8.8.8 (the 1472 is payload size; add 28 for the IP/ICMP headers to get total MTU). If it replies, try 1473, 1474, etc., until you get a “Packet needs to be fragmented” error. The highest successful value + 28 is your optimal MTU. Then set that value in your router’s WAN settings.

Frequently Asked Questions

Why can I access the site on my phone but not my computer?

This usually points to a device-specific issue—most commonly a corrupted DNS cache, a proxy setting, or a firewall rule on your computer. Try flushing your DNS and disabling any security software temporarily. If that doesn’t work, check your computer’s proxy settings (Windows: Settings > Network & Internet > Proxy; macOS: System Settings > Network > Proxies).

What does ERR_CONNECTION_TIMED_OUT mean?

This error means your browser sent a request to the server but never received a response within the timeout period. It often indicates a network issue between you and the site—firewall blocking, overloaded server, or ISP routing problems. Restarting your router, flushing DNS, and trying a different network (like a mobile hotspot) can help isolate the cause.

Can an antivirus program block websites?

Yes. Many antivirus suites include web protection that scans URLs and can block ones it deems suspicious—sometimes incorrectly. Check your antivirus’s settings for web protection or firewall rules, and temporarily disable it to see if that resolves the issue. If it does, add the site to your antivirus’s whitelist.

Why does the site work in another browser but not my main one?

This indicates a browser-specific problem: a corrupt profile, an extension, or cached data. Try resetting your browser settings to default, clearing cache and cookies, or creating a new user profile. In Chrome, you can create a new profile by clicking your avatar > Add, and then test the site there.

Is it safe to switch to a public DNS like 1.1.1.1?

Yes, public DNS providers like Cloudflare and Google are widely used and generally improve privacy and speed compared to ISP DNS. They don’t sell your browsing history, and they support encrypted DNS (DoH/DoT) for extra security. The main trade-off is trusting a third party with your DNS queries—but most users find the benefits outweigh the risks.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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