Firefox: Long lines in text area not visible

Solution 1:

I can see 2 methods that will partially meet your needs:

1. The masking or wrapping of such lines in Firefox are because Firefox by default obeys the css built into the page. One way to view the page without the css, and thus see the raw number display, is to install the web developer toolbar:

   Web Developer

   and then toggle the css display by using the key combination:

   Alt+Shift+A

2. Another choice is to perhaps permanently display all long lines without line wrapping. This was a behavior introduced with Firefox 22 as explained here. To reverse this you will need to follow these steps (taken from the linked article):

   • Type about:config into the address bar and hit enter.
   • Confirm that you will be careful if this is the first time you open this page
   • Use the search at the top to filter for plain_text.wrap_long_lines.
   • Double-click the value to set it to false which deactivates the feature.
   • To restore the original value at any time, repeat the steps abov

Not exactly what you are after but probably as close as you will get...

Solution 2:

If you want to see whether there is one long line or whether there are several short lines - there is a simple way to tell. Just resize your Firefox window (to a larger width, if possible). If the text re-flows to fit the new width then it is a single long (logical) line. If it keeps the same lines, then these are multiple short lines.

You can also get some hint when resizing to a smaller width. If you have multiple short lines they may wrap into two lines but you will be able to detect the line breaks.

This method works with many text-centric web pages, for example this one. Other web pages display text with a fixed line width regardless of the window size (this very page is an example). With these pages, resizing won't provide any information, unless you tweak the text properties (e.g. as suggested by @andrew.46).