# What does “overfull hbox” mean?

I often see output from TeX with the warning overfull hbox, badness 10000. What does this message mean?

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what is it with asking a question and answering it yourself straight away? –  Vivi Jul 26 '10 at 19:43
they are "seeding" which means asking and answering their own questions to build a nice bedrock of "good" questions so that newbies to the site will have good examples. –  BBischof Jul 26 '10 at 19:48
Would whoever down-voted care to comment why? –  Novelocrat Jul 26 '10 at 19:49
Aye! The whole point of the private beta is to seed answers to questions that we anticipate may be common. Answering your own question is perfectly acceptable if you have a good answer but no one has bothered to ask the question yet. –  Sharpie Jul 26 '10 at 20:18
Yes, but! Please do give some time before answering so that others have a chance as well. This also has the effect of producing novel answers which you might have not known otherwise! meta.tex.stackexchange.com/questions/4/… –  Juan A. Navarro Jul 28 '10 at 16:45

The first answer doesn't really help somebody fix the problem, though. Take a look at:

http://www.tex.ac.uk/cgi-bin/texfaq2html?label=overfull

and

http://en.wikibooks.org/wiki/LaTeX/Formatting#Hyphenation

to learn about \tolerance, \pretolerance, and \hyphenpenalty and how they affect the overfull/underfull behavior. Also, if you're fixing the document by hand, you can add hyphenation dictionary entries with \hyphenation or add discretionary hyphens into words with \-.

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This message means that a line of your document is too long to fit within the horizontal space on the page, and TeX couldn't find a good way to break it apart. This will usually result in text hanging out past the margin, possibly even running off the side of the page. Common causes are long words without proper hyphenation information and long displayed equations.

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If you use draft mode (\documentclass[draft]{article}) you can see black lines on the side of your document where there is overfull hbox badness. This is a convenient way to find and fix these errors. –  Otis Jul 26 '10 at 19:54
@Otis: thanks, I never knew that. –  Novelocrat Jul 26 '10 at 19:58
@Otis: Or simply something like \overfullrule=1mm so that you don't get the unwanted side effects of the "draft" mode. –  Jukka Suomela Jul 26 '10 at 20:34
Overfull hboxes are not limited to overlong lines on a page. A hbox can overflow anywhere, for example, inside a table. Whithout \overfullrule in effect this is often hard to detect. –  Christian Lindig Apr 17 '11 at 5:06