Chrome Network Internals and Cache Information

There are several features that are not available from the Settings menu, which you can only access using the chrome:// commands. Some of the features are available under both Menu and chrome:// commands. One of the most useful, underutilized and hidden features in Chrome is the network internals tools that you access by manually entering chrome://net-internals into your address bar. All chrome:// addresses need to be input by the user as links don’t work. It will immediately begin to start capturing network data, which you can stop by going to Capture at the top and clicking stop. You are able to see just about every aspect of Chrome’s internals from this area.

Among the various properties you are able to extract and analyze are:

• Proxy
• Events
• Timeline
• DNS
• Sockets
• Alt-Svc
• HTTP/2
• QUIC
• SDCH
• Cache
• Modules
• HSTS
• Bandwidth
• Prerender

Here is an example which illustrates a request for text/html data which was retrieved from the NGINX cache and not from the origin, whether that be on the same server or upstream half way around the world. I have NGINX configured with a custom HTTP header called “x-nginx-cache”. That field will always either contain a HIT or MISS value, depending if the server already has a copy of the content being requested in its local cache due to loading that content in the recent past without the cached object expiring.

cache-control:max-age=864000
cf-ray:39ec36096f207942-LAX
content-encoding:gzip
content-type:text/html; charset=UTF-8
date:Fri, 15 Sep 2017 14:17:42 GMT
expires:Mon, 25 Sep 2017 14:17:42 GMT
link:<https://blog.travisrunyard.us/wp-json/>; rel="https://api.w.org/"
link:<https://wp.me/p2SXGn-hL>; rel=shortlink
pragma:no-cache
server:cloudflare-nginx
set-cookie:wfvt_947412895=59bbdf0586a7b; expires=Fri, 15-Sep-2017 14:39:09 GMT; Max-Age=1800; path=/; secure; HttpOnly
status:200
vary:Accept-Encoding
x-content-type-options:nosniff
x-nginx-cache:HIT

Here is a listing of the most useful chrome:// commands:

1. chrome://flags

From here you can enable some of the experimental features that are hidden in the google Chrome browser. Please note that as mentioned on this page, since these are experimental, these might not work as expected and might cause issues. Enable these features and use it at your own risk.

2. chrome://dns

This displays the list of hostnames for which the browser will prefetch the DNS records.

3. chrome://downloads

This is also available from the Menu -> Downloads. Short cut key is Ctrl+J

4. chrome://extensions

This is also available from the Menu -> Tools -> Extensions

5. chrome://bookmarks

This is also available from the Menu -> Bookmarks -> Bookmark Manager. Short cut key is Ctrl+Shift+O

6. chrome://history

This is also availble from the Menu -> History. Short cut key is Ctrl+H

7. chrome://memory

This will redirect to “chrome://memory-redirect/”. This will display the memory used by Google chrome browser, and all other browsers running on the system (including firefox).

This also display all the process related to browser with their PID, process name, and the memory it takes.

8. chrome://net-internals

This displays all networking related information. Use this to capture network events generated by the browser. You can also export this data. You can view DNS host resolver cache.

One of the important feature in this feature is “Test”. If a URL failed to load, you can go to “chrome://net-internals” -> click on “Tests” tab -> type that URL which failed, and click on “Start Test”, which will do some test and report you why that URL failed.
chrome://plugins/

9. chrome://quota-internals

This gives information about the disk space quote used by the browser, including the break down of how much space the individual websites took under temporary files.

10. chrome://sessions

This displays the number of sessions and magic list that are currently running.

11. chrome://settings

This is also available from the Menu -> Options (on Windows), and Menu -> Preferences (on Linux). From here you can control various browser related settings.

12. chrome://sync-internals

This gives information about the chrome sync feature, including the Sync URL used by google, and sync statistics.

Finally, to view all the available chrome:// commands, type chrome://about/ in your chrome browser URL as shown below.

Also, please note that all of the commands mentioned above can also be called using google chrome about command, which redirects to chrome://.

For example, both of the following are exactly the same.

about:dns
chrome://dns