ERB (Embedded Ruby) is Ruby's templating system and the default view format in Ruby on Rails. runs Ruby code, outputs its result, and is a comment.

Does this formatter change my Ruby code?

No. ERB tags are protected with placeholders and restored verbatim; only the HTML structure and indentation around them change.

ERB Formatter: Beautify Rails .html.erb Templates

Format ERB templates while preserving embedded Ruby delimiters and HTML structure without executing code.

About ERB Beautify / Minify

Format or minify Ruby on Rails ERB templates. Every <% %>, <%= %>, <%- %> and <%# %> tag is swapped for a placeholder while the surrounding HTML is indented with js-beautify, then restored, and HTML between ERB block openers (if, each ... do, etc.) and their end is indented to match. Ruby code is never executed or reformatted, and a check warns when the counts of <% and %> do not match.

Common uses

Re-indent a Rails view where HTML and control flow have drifted out of alignment.
Clean up a partial pasted from a code review or an old project before editing it.
Find an unterminated ERB tag by comparing <% and %> counts.
Minify an ERB template's HTML whitespace and comments while keeping the Ruby tags intact.

FAQ

What is ERB?: ERB (Embedded Ruby) is Ruby's templating system and the default view format in Ruby on Rails. <% %> runs Ruby code, <%= %> outputs its result, and <%# %> is a comment.
Does this formatter change my Ruby code?: No. ERB tags are protected with placeholders and restored verbatim; only the HTML structure and indentation around them change.