ERR_ADDRESS_UNREACHABLE: What It Means and How to Fix It

When a browser throws the ERR_ADDRESS_UNREACHABLE error, it's telling you that it tried to connect to a specific address (domain name or IP), but the connection was blocked or couldn't be made. Unlike some other browser errors that point to slow responses or bad certificates, this one's about accessibility—it can't even begin the conversation with the destination.

This post will help you understand what causes this error, how it differs from similar messages, and how to go step by step to fix it.

What Triggers ERR_ADDRESS_UNREACHABLE?

To really understand what triggers the ERR_ADDRESS_UNREACHABLE, we need to know what's going on under the hood with a quick breakdown of how a browser connects to a website:

1. You enter a domain name into your browser.
   
2. Your computer asks a DNS server to translate that domain into an IP address.
   
3. Your browser opens a network socket and tries to connect to that IP over a specific port (usually 80 or 443).
   
4. Your request travels through routers and firewalls to the destination.
   
5. The server receives your request, processes it, and sends back a response.

When something blocks step 2 (DNS) or step 3 (connecting to the IP), the request fails and triggers the ERR_ADDRESS_UNREACHABLE response.

This error is unique from other browser-type errors because it's not caused by the server being slow or rejecting your request. If that were the case, you'd likely see a different message (like a timeout or a connection refused error).

Instead,  ERR_ADDRESS_UNREACHABLE is telling you the browser can't even find a working path to the destination because the path to the address is blocked, has been lost, or missing entirely.

Common Causes of ERR_ADDRESS_UNREACHABLE

Understanding the root cause depends on whether you're working on a home network, inside an office, using a proxy/VPN, or working with local development tools. Let's break it down.

1. Network Problems on Your Device or Router

Most of the time, this error points to something on your local network. Examples include:

• Disconnected or weak internet: If your Wi-Fi is unstable or you've lost connection completely, your browser will fail to reach any address.
  
• Router issues: If the router's internal settings are misconfigured or its cache is full, it might fail to route your request to the internet.
  
• DNS misconfiguration: If your DNS server isn't resolving domain names properly, or you're using a DNS that doesn't respond, your device might not know where to send your request—even if your internet is otherwise working.

2. Server-Side Problems

Sometimes the problem is at the destination:

• The server is offline or restarting. You might be trying to reach a server that's turned off or in the middle of maintenance.
  
• The server has a firewall rule blocking certain IPs or regions. You may be unknowingly blocked by country-based restrictions or security filters.
  
• The IP address or DNS record has recently changed. If the domain used to point to one IP address but now points to another, some DNS servers may still be caching the old value.

3. Typo or Incorrect Address

It sounds basic, but this is often overlooked. Double-check:

• Spelling of the domain (e.g., gooogle.com won't work)
  
• That you're using the correct port number if you're including one (localhost:8080)
  
• That you haven't accidentally entered an internal IP that's not part of your network (192.168.x.x, 10.x.x.x, etc.)

4. Proxy or VPN Interference

Many users (and corporate networks) use proxies or VPNs to route traffic through a different IP. If the proxy or VPN:

• Is down
  
• Is misconfigured
  
• Doesn't have access to the destination network

...your connection will fail before reaching the server.

Sometimes, your system or browser may be configured to use a proxy you're unaware of, especially on shared devices..

5. Firewall, Antivirus, or Security Software

Security tools can block connections that look suspicious. This might include:

• Traffic to non-standard ports
  
• Requests to internal IP addresses
  
• Connections to countries or regions flagged as "unsafe"

Troubleshooting ERR_ADDRESS_UNREACHABLE

1. Check Your Internet Connection

A tried and true method…Before diving deeper, it's worth confirming that your device is actually connected to the internet. The ERR_ADDRESS_UNREACHABLE error can sometimes appear simply because there's no active connection.

Start with a quick test:

• Open a well-known site like Google
  
• If that page also fails to load, your connection might be down.

Here are a few things you can try:

• Reconnect to Wi-Fi:
  Sometimes the connection drops silently, especially on mobile devices or laptops that frequently switch networks. Turn Wi-Fi off and back on again, or reconnect to your current network manually.
  
• Restart your modem and router:
  Power cycling your networking equipment can clear out temporary issues. Unplug the modem and router, wait about 30 seconds, then plug them back in and wait for them to reconnect.
  
• Try a different device:
  If you have another device handy—like a phone, tablet, or another computer—see if the same site loads there using the same network.
  • If it works, the problem may be isolated to one device.
  • If it fails everywhere, it points to a network-level issue (like a DNS or routing problem on your ISP's side).
• Switch to a different network:
  If you're on Wi-Fi, try using mobile data (or vice versa) to check if the issue is tied to your current connection.

If all other websites are working fine and only one specific site is showing the ERR_ADDRESS_UNREACHABLE message, that's your cue to move on to more site-specific fixes—like checking the site URL, your DNS settings, or whether a proxy or firewall is interfering.

2. Try a Different Browser or Device

If restarting your equipment didn't help, the issue might be on your end, more specifically, tied to how one browser or device is handling the connection.

Try opening the same URL in a different browser (like switching from Chrome to Firefox), or check the site from a different device entirely on the same network.

Here's what this comparison can tell you:

• If the site works in a different browser: The problem may be caused by an extension, outdated browser settings, or your browser's cached data in.
  
• If the site works on a different device: That points to a system-wide issue on the original device. Things like firewall rules, proxy settings, or even a local DNS cache could be getting in the way.
  
• If the site fails everywhere: That suggests the issue might still be tied to your network or the destination itself. In that case, keep moving through the steps.

By isolating the environment where the error occurs, you'll get a better idea of where to focus your troubleshooting efforts.

3. Flush Your DNS Cache

If the issue still persists, it's worth checking whether your device is holding onto outdated or bad DNS records. These records help translate domain names into IP addresses that browsers use to connect to websites. But if the saved information is wrong or expired, it can block access—even if the site itself is working fine.

Clearing the DNS cache forces your system to fetch fresh records the next time you visit a site. It's a quick and safe step that often resolves connection errors like ERR_ADDRESS_UNREACHABLE.

Here's how to flush your DNS cache:

On Windows:

1. Open the Start Menu and search for Command Prompt.
   
2. Right-click it and select Run as administrator.

In the Command Prompt window, type:

ipconfig /flushdns

3. Press Enter. You should see a confirmation message.

On macOS:

1. Open Terminal (you can find it in Applications > Utilities).

Type the following command and press Enter:

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

2. You may be prompted to enter your password.

Once complete, reopen your browser and try accessing the site again. If DNS was the issue, this step should help fix it.

4. Disable Proxy or VPN (Temporarily)

Still not getting through? If you're using a proxy or VPN, it might be the reason. These tools route your internet traffic through external servers, which can sometimes introduce connection issues, especially if the server you're tunneling through can't reach the website you're trying to access.

Try disabling your VPN or proxy service temporarily and refresh the page. If the site loads, there's a good chance the issue lies with your current routing method.

This also applies to corporate or managed networks that use automatic proxy configuration files. These settings can reroute traffic without you realizing it, especially on work devices.

After testing, you can always re-enable your VPN or proxy if needed.

5. Double-Check the Address and Port

If you're still stuck, it's worth confirming the address and port you're trying to reach, especially if you're working with a local servert. A quick check here can save you from chasing down other issues that aren't the real cause.

For local projects:

• Make sure the server is actually running.
  
• Confirm you're using the correct port number. For example, localhost:3000 is very different from localhost:8000.
  
• Check your server's binding settings. If it's bound only to 127.0.0.1 (localhost), it won't accept connections from other devices—even if they're on the same network.

If you're trying to access a public site, review the URL for typos or unexpected port numbers (like :8080). Browsers won't always warn you if a custom port is incorrect or not open on the server's side, they'll just give you a generic "site can't be reached" message.

6. Switch Networks (Optional, but Useful)

If you're still seeing the error, try connecting to a different network. For example, you can temporarily switch to a mobile hotspot or another Wi-Fi connection.

If the site loads fine on the new network, that's a strong sign the issue is tied to your original internet connection. It could be something like:

• A firewall rule on your router
  
• ISP-level restrictions
  
• A misconfigured DNS setting or security filter on the network

This step isn't always necessary, but it can help you quickly narrow down whether the problem is with your system or the network it's on.

How This Error Differs From Other Browser Connection Errors

Each browser error gives you a slightly different hint about what's going wrong. Here's how this one compares:

• ERR_NAME_NOT_RESOLVED: The domain couldn't be converted into an IP address. Usually a DNS issue.
  
• ERR_CONNECTION_TIMED_OUT: The server took too long to respond, but the connection was attempted.
  
• ERR_CONNECTION_REFUSED: The server was reached but explicitly denied the connection.
  
• ERR_ADDRESS_UNREACHABLE: No connection was made at all. The browser couldn't find a valid path to the server.

Wrapping Up

ERR_ADDRESS_UNREACHABLE can be a frustrating error to run into, especially when there's no clear message telling you why the site can't be reached. But by breaking it down and testing your connection from different angles—DNS, local settings, proxy rules, server availability—you can usually find the problem and fix it.

Whether you're troubleshooting from a user's perspective or debugging a server or app as a developer, the steps above should help you pinpoint where the connection is breaking down.

FAQs About ERR_ADDRESS_UNREACHABLE

Q: Is this the same as a DNS error?

A: No. DNS errors usually show as ERR_NAME_NOT_RESOLVED. ERR_ADDRESS_UNREACHABLE means your browser knows where to go but can't get there.

Q: Can this error be caused by my hosting provider?

A: Yes, especially if firewall rules or IP bindings aren't configured correctly on your VPS or dedicated server.

Q: What if I only see this error on certain networks?

A: The network you're on might be blocking access to specific ports or IPs. Public Wi-Fi and corporate environments do this often.

Q: Do I need to flush DNS on both system and browser?

A: Flushing the system DNS is usually enough. However, browser caches can sometimes cause lingering problems, so restarting your browser or using incognito mode can help.