How to make Twitter Bootstrap tooltips have multiple lines?

You can use the html property: http://jsfiddle.net/UBr6c/

My <a href="#" title="This is a<br />test...<br />or not" class="my_tooltip">Tooltip</a> test.

$('.my_tooltip').tooltip({html: true})

If you're using Twitter Bootstrap Tooltip on non-link element, you can specify, that you want a multi-line tooltip directly in HTML code, without Javascript, using just the data parameter:

<span rel="tooltip" data-html="true" data-original-title="1<br />2<br />3">5</span>

This is just an alternative version of costales' answer. All the glory goes to him! :]

You can use white-space:pre-wrap on the tooltip. This will make the tooltip respect new lines. Lines will still wrap if they are longer than the default max-width of the container.

.tooltip-inner {
    white-space:pre-wrap;
}

http://jsfiddle.net/chad/TSZSL/52/

If you want to prevent text from wrapping, do the following instead.

.tooltip-inner {
    white-space:pre;
    max-width:none;
}

http://jsfiddle.net/chad/TSZSL/53/

Neither of these will work with a \n in the html, they must actually be actual newlines. Alternatively, you can use encoded newlines 
, but that's probably even less desirable than using <br>'s.