Ruby wrapper for UglifyJS JavaScript compressor.


Uglifier is available as ruby gem.

$ gem install uglifier

Ensure that your environment has a JavaScript interpreter supported by ExecJS. Usually, installing therubyracer gem is the best alternative.


require 'uglifier'"source.js"))
# => js file minified

# Or alternatively

When initializing UglifyJS, you can tune the behavior of UglifyJS by passing options. For example, if you want top-level variable names to be mangled: => true).compile(source)

# Or
Uglifier.compile(source, :toplevel => true)

Available options and their defaults are

  :mangle => true, # Mangle variables names
  :toplevel => false, # Mangle top-level variable names
  :except => [], # Variable names to be excluded from mangling
  :max_line_length => 32 * 1024, # Maximum line length
  :squeeze => true, # Squeeze code resulting in smaller, but less-readable code
  :seqs => true, # Reduce consecutive statements in blocks into single statement
  :dead_code => true, # Remove dead code (e.g. after return)
  :lift_vars => false, # Lift all var declarations at the start of the scope
  :unsafe => false, # Optimizations known to be unsafe in some situations
  :copyright => true, # Show copyright message
  :ascii_only => false, # Encode non-ASCII characters as Unicode code points
  :inline_script => false, # Escape </script
  :quote_keys => false, # Quote keys in object literals
  :beautify => false, # Ouput indented code
  :beautify_options => {
    :indent_level => 4,
    :indent_start => 0,
    :space_colon => false

Submitting an issue

Uglifier uses the GitHub issue tracker to track bugs and features. Before submitting a bug report or feature request, check to make sure it hasn't already been submitted. You can indicate support for an existing issuse by voting it up. When submitting a bug report, please include a Gist that includes a stack trace and any details that may be necessary to reproduce the bug, including your gem version, Ruby version, MultiJSON engine and ExecJS runtime. Ideally, a bug report should include a pull request with failing specs.

Contributing to uglifier