A typesetting proof tool
Paste your copy, set the measure, and Rag Right marks up widows, holes and wedges the way a proofreader’s red pencil would. Then it resets the breaks so the rag reads clean.
Non-photo blue shows the white space each line leaves at the measure.Red pencil marks the breaks that need a pass.
The marks
One word stranded alone on the last line of a paragraph. It reads as an accident and breaks the shape of the block.
Two words, but still less than a third of the measure. Legal, not lovely. Worth a second look in display type.
A line that falls far short of its neighbors. It punches a bite out of the rag and pulls the eye off the text.
Three or more lines stepping steadily in or out. The rag turns into a staircase instead of a gentle, irregular edge.
How it works
Your copy is set live in the real typeface, then every word and word space is measured exactly as the browser draws it.
Each line is checked against the measure and against its neighbors for widows, short ends, holes and wedges.
A minimum-raggedness pass, a cousin of the Knuth–Plass algorithm behind TeX, weighs every possible break and picks the set with the cleanest edge.