How can I dump the entire Web DOM in its current state in Chrome?
Command line solution
This is easy to do with newer releases of Chrome:
google-chrome --headless --dump-dom 'http://www.yahoo.com'
(The OP may not have been looking for a command line solution but this search result appears high when searching so others might find it useful)
Original answer 2017
My favorite way to do this is:
docker run -it --rm --name chrome --shm-size=1024m --cap-add=SYS_ADMIN --entrypoint=/usr/bin/google-chrome-unstable yukinying/chrome-headless-browser --headless --disable-gpu --dump-dom https://www.facebook.com
If you're not familiar with how Docker works, be patient - the first time will be slow but subsequent invocations will be quick.
Other information
Tested on
Ubuntu 16
Linux intel-nuc 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:33:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
Docker version:
Docker version 1.10.3, build 20f81dd
Mac OS X Sierra
Darwin MacBook-Pro.local 16.7.0 Darwin Kernel Version 16.7.0: Thu Jun 15 17:36:27 PDT 2017; root:xnu-3789.70.16~2/RELEASE_X86_64 x86_64 i386 MacBookPro14,3 Darwin
Docker version:
Docker version 17.06.1-ce, build 874a737
If you install tidy you can indent the HTML too.
In Chrome Dev Tools Console, type document.documentElement.outerHTML (use the tab button for autocomplete to save keystrokes) and hit Enter to see the DOM text displayed. To copy it to your clipboard and paste it elsewhere, use copy(document.documentElement.outerHTML) instead.
Damon's answer is also good (in Dev Tools, click Elements, right click <html>, click Copy > Copy outerHTML), but I find the Console command easier.
Using the Web Inspector (F12), go to the Elements tab, right click on the <html> tag in your code and select Copy->Copy outerHTML. Then paste that into a new file and save.