::
_____ _ _____ __ __ _____ _______
/ ____| | |_ _| \/ |_ _|__ __|
| (___ | | | | | \ / | | | | |
\___ \| | | | | |\/| | | | | |
____) | |____ _| |_| | | |_| |_ | |
|_____/|______|_____|_| |_|_____| |_|
SlimIt is a JavaScript minifier written in Python.
It compiles JavaScript into more compact code so that it downloads
and runs faster.
SlimIt also provides a library that includes a JavaScript parser,
lexer, pretty printer and a tree visitor.
http://slimit.readthedocs.org/ <http://slimit.readthedocs.org/>_
::
$ [sudo] pip install slimit
Or the bleeding edge version from the git master branch:
::
$ [sudo] pip install git+https://github.com/rspivak/slimit.git#egg=slimit
There is also an official DEB package available at
http://packages.debian.org/sid/slimit <http://packages.debian.org/sid/slimit>_
From the command line:
::
$ slimit -h
Usage: slimit [options] [input file]
If no input file is provided STDIN is used by default.
Minified JavaScript code is printed to STDOUT.
Options:
-h, --help show this help message and exit
-m, --mangle mangle names
-t, --mangle-toplevel
mangle top level scope (defaults to False)
$ cat test.js
var foo = function( obj ) {
for ( var name in obj ) {
return false;
}
return true;
};
$
$ slimit --mangle < test.js
var foo=function(a){for(var b in a)return false;return true;};
Or using library API:
from slimit import minify text = """ ... var foo = function( obj ) { ... for ( var name in obj ) { ... return false; ... } ... return true; ... }; ... """ print minify(text, mangle=True, mangle_toplevel=True) var a=function(a){for(var b in a)return false;return true;};
from slimit.parser import Parser from slimit.visitors import nodevisitor from slimit import ast
parser = Parser() tree = parser.parse('for(var i=0; i<10; i++) {var x=5+i;}') for node in nodevisitor.visit(tree): ... if isinstance(node, ast.Identifier) and node.value == 'i': ... node.value = 'hello' ... print tree.to_ecma() # print awesome javascript :) for (var hello = 0; hello < 10; hello++) { var x = 5 + hello; }
from slimit.parser import Parser from slimit.visitors.nodevisitor import ASTVisitor
text = """ ... var x = { ... "key1": "value1", ... "key2": "value2" ... }; ... """
class MyVisitor(ASTVisitor): ... def visit_Object(self, node): ... """Visit object literal.""" ... for prop in node: ... left, right = prop.left, prop.right ... print 'Property key=%s, value=%s' % (left.value, right.value) ... # visit all children in turn ... self.visit(prop) ...
parser = Parser() tree = parser.parse(text) visitor = MyVisitor() visitor.visit(tree) Property key="key1", value="value1" Property key="key2", value="value2"
from slimit.lexer import Lexer lexer = Lexer() lexer.input('a = 1;') for token in lexer: ... print token ... LexToken(ID,'a',1,0) LexToken(EQ,'=',1,2) LexToken(NUMBER,'1',1,4) LexToken(SEMI,';',1,5)
You can get one token at a time using token method:
lexer.input('a = 1;') while True: ... token = lexer.token() ... if not token: ... break ... print token ... LexToken(ID,'a',1,0) LexToken(EQ,'=',1,2) LexToken(NUMBER,'1',1,4) LexToken(SEMI,';',1,5)
LexToken instance has different attributes:
lexer.input('a = 1;') token = lexer.token() token.type, token.value, token.lineno, token.lexpos ('ID', 'a', 1, 0)
SAM - JQuery size after minification in bytes (the smaller number the better)
+-------------------------------+------------+------------+------------+ | Original jQuery 1.6.1 (bytes) | SlimIt SAM | rJSmin SAM | jsmin SAM | +===============================+============+============+============+ | 234,995 | 94,290 | 134,215 | 134,819 | +-------------------------------+------------+------------+------------+
when doing name mangling handle cases with 'eval' and 'with'
foo["bar"] ==> foo.bar
consecutive declarations: var a = 10; var b = 20; ==> var a=10,b=20;
reduce simple constant expressions if the result takes less space: 1 +2 * 3 ==> 7
IF statement optimizations
remove unreachable code that follows a return, throw, break or continue statement, except function/variable declarations
parsing speed improvements
PLY <http://www.dabeaz.com/ply/>_jslex <https://bitbucket.org/ned/jslex>_pycparser <http://code.google.com/p/pycparser/>_rkelly <https://github.com/tenderlove/rkelly>_UglifyJS <https://github.com/mishoo/UglifyJS>_pyjsparser <http://bitbucket.org/mvantellingen/pyjsparser>_The MIT License (MIT)
FAQs
SlimIt - JavaScript minifier
We found that slimit demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
Create React App is officially deprecated due to React 19 issues and lack of maintenance—developers should switch to Vite or other modern alternatives.
Security News
Oracle seeks to dismiss fraud claims in the JavaScript trademark dispute, delaying the case and avoiding questions about its right to the name.
Security News
The Linux Foundation is warning open source developers that compliance with global sanctions is mandatory, highlighting legal risks and restrictions on contributions.