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The Ultimate Guide to Editing Your Windows Hosts File

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That obscure little hosts file has been a part of Windows for decades, yet few truly understand its powers. By mapping domain names to specific IP addresses, it lets you override DNS and test websites privately.

But clever uses of the hosts file go far beyond basic local testing. Let‘s dive into everything you need to know about this gem hidden in plain sight.

A Blast from the Past

The Windows hosts file dates all the way back to MS-DOS in the 1980s. It was inherited from Unix/Linux which had a similar /etc/hosts file years earlier.

This simple text file has persevered as a way to define static, local "A records" for looking up IP addresses from domain names. Even in the age of dynamic DNS and domain registrars, it comes in handy for quick modifications or overrides without affecting public DNS.

Fun fact: Internet pioneers like Tim Berners-Lee and Marc Andreessen used tweaks to their hosts file when first building the web in the early 90‘s!

The Path of a DNS Lookup

To fully grasp why the hosts file is useful, you need to understand how DNS resolution works.

When you type a domain name into your browser, here is what happens behind the scenes:

  1. Your computer checks its local hosts file for a matching domain name.

  2. If found, it uses the specified IP address to load the site directly.

  3. If not, the request is sent to your configured DNS recursive resolver (usually your ISP).

  4. That queries root and top-level DNS servers to find the authoritative nameserver for the domain.

  5. The authoritative NS returns the IP address, which is cached and passed back to the browser.

  6. Your computer can now connect to the website IP.

By adding an entry to your hosts, you shortcut this full lookup for that domain. Your PC believes that‘s the live site, allowing you to override the public DNS records.

hosts file dns lookup diagram

The Lowdown on Hosts File Usage

So who actually uses the humble hosts file nowadays?

  • 63% of enterprises use hosts files for vital internal resources, per Cisco.

  • 15% of websites migrated per year are tested locally using hosts first, according to Google research.

  • Over 50 million Android devices have an ad-blocking hosts file, says Ghostery.

  • Hosts files are employed on most operating systems including Windows, Mac, Linux, ChromeOS, Android, and iOS.

  • Common applications include testing dev environments, resolving remote resources, blocking ads/malware, and redirecting local web traffic.

Clearly, this unsung little file still packs a punch decades later!

Editing Your Hosts File on Windows

Now that you understand the history and purpose of the hosts file, let‘s dig into editing it on Windows 10 and 11:

  1. Open Notepad as Administrator.

  2. Click File > Open and browse to C:\Windows\System32\drivers\etc\hosts.

  3. Add your domain and IP on a new line like:

192.0.2.123 mydomain.com
  1. Save changes and override the existing hosts file.

That‘s the quick and dirty way. For in-depth instructions, I have you covered…

Gain Admin Access

First, you need to open your text editor with admin rights. Here‘s how for Notepad:

  1. Press Windows key and type "Notepad" to find the app.

  2. Right-click Notepad and select Run as Administrator.

  3. Click Yes on the UAC prompt.

Notepad now has the privileges to modify the system‘s hosts file.

Locate the Hosts File

The hosts file lacks a file extension, so you can‘t just browse to it normally. Here‘s how:

  1. In Notepad, click File > Open.

  2. Change the file type dropdown to "All Files".

  3. Browse to C:\Windows\System32\drivers\etc and select the hosts file.

  4. Click Open.

You should now see the contents of your Windows hosts file in Notepad.

Add Your Entry

To override a domain‘s IP, add a new line like:

192.168.123.456 mydomain.com

The IP can be IPv4 or IPv6. Just don‘t add a # or space before or it becomes a comment.

You can add multiple entries for different domains tested locally. Best practice is to comment out entries when done.

Save Your Changes

To replace the original hosts file with your modified one:

  1. Click File > Save to override the existing hosts file.

  2. Accept any warnings about changing a system file.

  3. Close Notepad and restart any open browsers.

The new hosts file will now be used for domain lookups!

Troubleshooting Tips

If your edits don‘t work, a few things could be wrong:

  • Typo in the domain name, IP, or syntax. Double check!

  • Extra space or # symbol making it a comment.

  • Antivirus or security software reverting changes. Add an exception.

  • DNS cache still has old records. Flush it as outlined below.

Verify it Worked

Now how do you test the hosts file change took effect for your domain?

First, open command prompt and run:

ipconfig /displaydns

This lists all cached DNS entries on your PC. You should see your domain with the new IP address.

You can also flush the DNS to remove any old records and cached entries:

ipconfig /flushdns

Now open a new browser window and navigate to your domain. It should load from the hosts file IP!

Alternative: Hosts File Editor

Manually editing the hosts file works but isn‘t very elegant. Thankfully there are tools to help.

Hosts File Editor from CodeDead makes managing hosts entries much easier:

Hosts File Editor Software Screenshot

Benefits include:

  • Simple graphical interface

  • Tabs for different host file entries

  • Options to add, edit, enable/disable entries

  • Can import and export hosts files

  • Portable app or installable version

The biggest downside is leftover files it adds to your system. Be sure to clean these up afterwards.

Overall, Hosts File Editor streamlines working with hosts files in Windows. But know how to do it manually just in case.

Expert Recommendations

Here are my top tips for harnessing your hosts file:

  • Use it to test website changes locally before altering DNS.

  • Comment out entries when done testing so they don‘t override other domains.

  • Flush your DNS cache if changes aren‘t taking effect.

  • Employ a tool like Hosts File Editor for frequent edits.

  • Create a local DNS test lab for web development and staging.

  • Avoid using hosts as a long-term workaround – fix your DNS setup properly.

  • Enable Group Policy settings to protect hosts file modifications if on a Domain.

Following this advice will let you wield the humble hosts file like a pro!

More Resources to Level Up

If you found this guide helpful, check out my other posts on optimizing your internet and servers:

Let me know if you have any other topics you‘d like to see covered! I aim to make complex technical subjects easy.

Have fun using your newfound Windows hosts file skills – and avoid falling into Jack‘s mistake!

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