# Insert Special Symbols in \url

I have the following URL

http://www.wolframalpha.com/input/?i=density+destilled+water+23°C


Trying to insert this as a \footnote with \url I got an error. The same with

\footnote{\url{http:// [...] 23^{\circ}C}}


I hope you can help me!

• \url{http://www.wolframalpha.com/input/?i=density+distilled+water+23%C2%B0C} – giordano Jun 13 '15 at 18:52
• @giordano Not enough in the case of a footnote. \urldef will also have to be used. – Gonzalo Medina Jun 13 '15 at 19:00

When URLs contain special characters, and you want to use them in an argument (even in a moving argument), the standard approach is yo use \urldef. Below I give to two options:

1. Use \urldef:

\documentclass{amsart}
\usepackage{hyperref}

\urldef{\wxxiii}\url{http://www.wolframalpha.com/input/?i=density+destilled+water+23°C }

\begin{document}

\footnote{\wxxiii}

\end{document}


The resulting footnote:

2. Use

http://www.wolframalpha.com/input/?i=density+destilled+water+23%C2%B0C


(which you can get with the help of your browser) and \urldef:

\documentclass{amsart}
\usepackage{hyperref}

\urldef{\wxxiii}\url{http://www.wolframalpha.com/input/?i=density+destilled+water+23%C2%B0C}

\begin{document}

\footnote{\wxxiii}

\end{document}


The resulting footnote text: