Whitespace Cleaner

Four separate operations run in a fixed order, because the order changes the result. Tabs are expanded first, then runs of spaces are collapsed, then line ends are trimmed, then blank lines are handled. Trimming before collapsing would leave doubled spaces in the middle of lines; doing it this way does not.

Trailing whitespace is the invisible one. A space at the end of a line shows nothing on screen but makes two identical-looking lines different to every tool that compares them — deduplication, sorting, diffing, spreadsheet lookups. It is the most common cause of “these are the same, why does it say they are not”.

Blank lines have three settings rather than a switch, because the right answer differs. At most one in a row is what you want for prose, where paragraph breaks are meaningful but the four blank lines a PDF paste left behind are not. Remove all is for lists, where any blank line is noise.

The whole text is trimmed at the end, so leading and trailing blank lines around the block disappear too. Everything runs in your browser as you type.

You paste a customer list out of an emailed PDF. It looks like a list. It behaves like a minefield:

   Ahmad Nasser


  Sara Haddad
Omar   Khalil

Leading spaces on some lines, trailing spaces on others, a doubled space inside a name, and blank lines scattered through. The character counter reads 74.

With trim line ends on, collapse repeated spaces on and blank lines set to remove all, you get three clean lines and the counter reads 42 — a third of the content was invisible whitespace.

The important part is what this unblocks. Run that original list through deduplication and Sara Haddad with a trailing space will not match Sara Haddad without one. Sort it and the leading-space lines gather at the top, away from the rest. Clean first, then everything else works.

For prose rather than lists, set blank lines to at most one in a row instead — that keeps paragraph structure while removing the gaps a PDF paste inserts.