# What is the command to highlight bad boxes in pdf?

I seem to remember a command to show bad boxes in a PDF when using latex, but googling is not helping me to remember.

How can I show bad boxes in my PDF?

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add draft to the documentclass options. – Marco Daniel May 9 '11 at 16:50
Is there also an option for underfull hboxes? – white_gecko Apr 22 '13 at 9:30