This appends each line's character count directly to that line, turning a plain list into a measured one that can be sorted, filtered or eyeballed against a limit.
Why measure in place
Character limits are everywhere in marketing work — title tags, meta descriptions, ad headlines, SMS bodies, database columns. Knowing which specific entries breach a limit matters more than knowing that some of them do.
The advantage over a spreadsheet formula
A formula puts the count in an adjacent cell that has to be kept aligned with the text. Appending it to the line keeps measurement and subject together as one string, which survives copying, sorting and pasting between tools.
What comes next
Once every line carries its count, sorting by length puts the worst offenders at the top, and filtering by number isolates exactly the set that needs rewriting.
Try it: Append Character Count per Line on SeoWolf's Notepad.