# How of to change font size for every nodes in tikzcd?

How of to change font size for every nodes in tikzcd?

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz-cd}
\usetikzlibrary{arrows, matrix}
\tikzcdset{every label/.append style = {scale=0.6,yshift=0.2ex}}
\begin{document}
$\begin{tikzcd} 0\rar & \mathrm{Hom}_R(L, E) \arrow{r}{\mathrm{Hom}\!(\!\beta\!, \mathrm{id}\!_E\!)} & \mathrm{Hom}_R(N, E) \arrow{r}{\mathrm{Hom}(\alpha, \mathrm{id}_E)} & \mathrm{Hom}_R(M, E) \end{tikzcd}$
\end{document}


Since the TikZ cd is a TikZ matrix, you could use every matrix/.append style={nodes={font=...}}.

I would also leave out all those \! in the first label.

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz-cd}
\usetikzlibrary{arrows, matrix}
\tikzcdset{every label/.append style = {scale=0.6,yshift=0.6ex},
every matrix/.append style={nodes={font=\small}}
}
\begin{document}
$\begin{tikzcd} 0\rar & \mathrm{Hom}_R(L, E) \arrow{r}{\mathrm{Hom}(\beta, \mathrm{id}_E)} & \mathrm{Hom}_R(N, E) \arrow{r}{\mathrm{Hom}(\alpha, \mathrm{id}_E)} & \mathrm{Hom}_R(M, E) \end{tikzcd}$
\end{document}


Edit: As marmot pointed out, there is also the key cells=<options> which appends <options> to the style every cell, which, in turn, by default contains the following:

/tikz/shape=asymmetrical rectangle,
/tikz/inner xsep=1ex,
/tikz/inner ysep=0.85ex


See the tikzcd package documentation, Section 2.1 General options.

MWE:

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz-cd}
\usetikzlibrary{arrows, matrix}
\tikzcdset{
every label/.append style = {scale=0.6,yshift=0.6ex},
cells={nodes={font=\small}}
}
\begin{document}
$\begin{tikzcd} 0\rar & \mathrm{Hom}_R(L, E) \arrow{r}{\mathrm{Hom}(\beta, \mathrm{id}_E)} & \mathrm{Hom}_R(N, E) \arrow{r}{\mathrm{Hom}(\alpha, \mathrm{id}_E)} & \mathrm{Hom}_R(M, E) \end{tikzcd}$
\end{document}


The result is the same as before.

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz-cd}
\usetikzlibrary{arrows, matrix}
\tikzcdset{every label/.append style = {scale=0.6,yshift=0.2ex},
nodes={font=\footnotesize}}
\begin{document}
$\begin{tikzcd} 0\rar & \mathrm{Hom}_R(L, E) \arrow{r}{\mathrm{Hom}\!(\!\beta\!, \mathrm{id}\!_E\!)} & \mathrm{Hom}_R(N, E) \arrow{r}{\mathrm{Hom}(\alpha, \mathrm{id}_E)} & \mathrm{Hom}_R(M, E) \end{tikzcd}$
\end{document}