Utilizing the Windows, Linux, Mac, iPhone or Android HOSTS file is a great, lightweight way to reduce the bandwidth your device uses, increase privacy by blocking ads, analytics, banners, 3rd party Cookies, 3rd party page counters, web bugs, javascript, telemetry, hijackers and even unwanted programs. There is no software to install, only a simple text file. Your operating system automatically uses the HOSTS file at startup, so there is no need to turn on, adjust or change any settings. Your operating system automatically looks for the existence of a HOSTS file and if found, checks the HOSTS file first for entries to the connection you just requested. The 0.0.0.0 (prefix) is a dead end connection, so when an entry listed in your HOSTS file is requested on a page you are viewing, your computer thinks 0.0.0.0 is the location of the page. When this page fails to load, it skips onto the next request and thus any ad server is blocked from loading the banner, cookie, tracker, beacon, or javascript file.
Microsoft is well known for sending your data to its own servers. By loading known Microsoft connections into a HOSTS file, we can block most or all communication with Microsoft’s telemetry servers.
What you will notice is that web pages load magnitudes of times faster, you will see no or very few ads. Your data usage will drop dramatically on all devices using your HOSTS file. You may encounter a few web pages that fail to load. This is usually because its name is in your HOSTS file and thus unreachable. You may want to tweak the file somewhat when you encounter this situation. On the other hand, these web pages are usually not worth seeing anyway.
The speed increase is due to using less data and not having to wait for ads, banners, analytics, etc. to load. This also helps to protect your
privacy and
security by blocking sites that may track your viewing habits, also known as "click-thru tracking" or Data Miners. Simply using a HOSTS file is not a cure-all against all the dangers on the Internet, but it does provide another very effective "Layer of Protection".
Example - the following entry 0.0.0.0 ad.doubleclick.net blocks all files supplied by that DoubleClick Server to the web page you are viewing. This also prevents the server from tracking your movements. Why? ... because in certain cases "Ad Servers" like Doubleclick (and many others) will try silently to open a separate connection on the webpage you are viewing, record your movements then yes ... follow you to additional sites you may visit.
Another benefit of the HOSTS file is that malware cannot call home as long as the necessary entries exist. This is why it's important to keep your HOSTS file up to Date.
My secret weapon on how to create your own HOSTS entries.
There is a free tool called Fiddler that acts as a proxy server. With this tool, you can easily build an effective HOSTS file in seconds!
You now have a valid list of connections to block!
When you run Fiddler, you'll notice something disturbing: a single web page can have hundreds of http requests! Most of the payload is junk. You're only interested in about 1/100 of the data being requested. Now you know why the Internet is so slow! Lots of analytics, tons of javascript libraries, lots of small images. Blocking synchronous requests; it's amazing pages ever render at all! A web page should have no more than 20 https requests for performance reasons. But you'll routinely see hundreds of https requests. And on top of this, often the website isn't even compressing resources! How rude is that?
Check this site out for a
bad example of a website with well over 200 http requests
How to use
The typical workflow is to
- Copy/paste the contents of your existing hosts file into the text area below
- Select the options you prefer.
- Click 'Go'
- Look for any connections that are legitimate and remove them.
- Copy/paste contents of text area into your HOSTS file
Workflow using Fiddler
- Download Fiddler here.
- Start fiddler.
- Clear the session list
- Browse to a website you like. Visit a few pages.
- Select all sessions in Fiddler or select individual http requests
- Fiddler -> Edit -> Copy just the URL
- Paste into the list window on this page.
- Select the options you prefer.
- Click 'Go'
- Look for any connections that are legitimate and remove them.
- Copy/paste contents of text area into your HOSTS file
Pressing the "Go" button cleans and removes duplicate entries.
This tool can also be used to simply strip a list of complete URLs into endpoints.
This tool removes duplicates so you never have to worry about merging multiple sources of lists!
Editing HOSTS files in Windows may require you to start your text editor as Administrator. If you don't do this, you may not be able to save the file since the folder is generally protected.
Editing the hosts file in Unix/Linux will usually require you to edit the file using sudo to launch the editor for the same reason as above.
See Steven Blacks hosts file for More info
