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Default source code viewer command line


Not sure if this is the right place to ask this but does anyone know what is the command line to launch the built in source code viewer for FF please?

I've read someone that it's: "C:\Program Files (x86)\Mozilla Firefox\firefox.exe" "view-source"

But this doesn't work.

If anyone's able to shed some light on it, that would be great.


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  • Top 10 Contributor
  • Moderator
10749 solutions 96724 answers

You can prefix an URL with the view-source: protocol to see the page source.

Question owner


That works but I'm trying to add the default source code viewer to the ViewSourceWith extension.

I add the path to FF and if I add view-source: as parameter then when I click to check the source using those details, a page loads with the following address: view-source:file:///C:/Program%20Files%20%28x86%29/Mozilla%20Firefox/

The contents of the page seem to list all the .dll files being used by FF.

Is there anything I can add to the parameters to make it load the current page in the source viewer please?

Southerner 0 solutions 12 answers

The view source: does not give you the option to edit the source code. It only gives me the option to view it. I had notepad+ set as my external source viewer in version 16 but now I no longer have the option in 18 even though external viewer is set in config. What am I missing?

  • Top 10 Contributor
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10749 solutions 96724 answers

(fixed for Southerner as per: [/questions/939775#answer-406824])

Southerner 0 solutions 12 answers

I am back to having the same problem! When version 22.0 installed I lost the option to view source in Notepad++. The about lines still show that it should work but it does not. Control U brings up the source but in the Mozilla viewer which does not allow editing the source. What am I missing and why does it get reset?

I also noticed that with version 22 (32 bit for XP) the default printer is not the windows default printer but keeps the last printer used in Firefox even if that printer no longer exists.

Thank you for the help.