jQuery 1.4.2 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 163855 bytes (160.0k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 72174 bytes (70.5k, 44%).

After GZIP compression these minified files vary in size:

Microsoft	31254 bytes (30.5k)	CDN
Boot	28573 bytes (27.9k)	CDN
Baidu	24836 bytes (24.3k)	CDN
cdnjs	24751 bytes (24.2k)	CDN
gzip -6 (default)	24625 bytes (24.0k)	local copy
Google	24605 bytes (24.0k)	CDN
gzip -9	24575 bytes (24.0k)	local copy
7zip -mx=9 -tgzip	23869 bytes (23.3k)	local copy
kzip -s0 -rn -b5	23833 bytes (23.3k)	local copy
zultra	23821 bytes (23.3k)	local copy
libdeflate -12	23799 bytes (23.2k)	local copy
Yandex	23793 bytes (23.2k)	CDN
pigz -11 -n	23781 bytes (23.2k)	local copy
Zopfli	23745 bytes (23.2k)	local copy
Zopfli (defluff)	23743 bytes (23.2k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-1.4.2.min.js (or via HTTPS)

You will automatically get the smallest jQuery 1.4.2 file, ETag caching is available and
if your browser doesn't support GZIP decompression then the uncompressed version will be sent.

Currently best Zopfli settings

Save 48 bytes by using my jQuery 1.4.2 Zopfli version instead of the best available CDN (0.20% smaller than Yandex, 23745 vs. 23793 bytes):

Download

You can use my super-compressed files for whatever purpose you like as long as you respect the library's original license agreement.
There are no restrictions from my side - but please avoid hot-linking if you run a high-traffic website.

These command-line settings yielded the best compression ratio so far (Linux version of zopfli-krzymod):
zopfli --i100000 --mb8 --mls8 --bsr16 --lazy --ohh

(found October 21, 2015)

Description	Value	Parameter
iterations	100000	--i100000
maximum blocks	8	--mb8
maximum length score	8	--mls8
block splitting recursion	16	--bsr16
lazy matching in LZ77	yes	--lazy
optimized Huffman headers	yes	--ohh
initial random W for iterations	1	--rw1
initial random Z for iterations	2	--rz2

Even Smaller Files Thanks To Defluff

Zopfli's output can be further optimized by the defluff tool.
In this particular case, defluff saves 2 more bytes (23743 bytes).

Download

Verify file integrity

After decompression, my uncompressed files are identical to the original ones:

MD5:
curl --silent --compressed https://code.jquery.com/jquery-1.4.2.min.js --location | md5sum
10092eee563dec2dca82b77d2cf5a1ae -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.4.2.min.zopfli.js.gz | md5sum
10092eee563dec2dca82b77d2cf5a1ae -

SHA1:
curl --silent --compressed https://code.jquery.com/jquery-1.4.2.min.js --location | sha1sum
65cbff4e9d95d47a6f31d96ab4ea361c1f538a7b -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.4.2.min.zopfli.js.gz | sha1sum
65cbff4e9d95d47a6f31d96ab4ea361c1f538a7b -

These CDNs send you the original file:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	28573 bytes	10092eee563dec2dca82b77d2cf5a1ae	March 18, 2015 @ 09:41
cdnjs	24751 bytes	10092eee563dec2dca82b77d2cf5a1ae	(invalid)
Google	24605 bytes	10092eee563dec2dca82b77d2cf5a1ae	(invalid)
Yandex	23793 bytes	10092eee563dec2dca82b77d2cf5a1ae	June 15, 2015 @ 21:17

And some CDNs send you a different file:

CDN	Size (compressed)	MD5 (uncompressed)	Comment / Diff	Timestamp
Microsoft	31254 bytes	e055c570668301b71137281a0ce65560	< /! > / < * http://jquery.com/ < * < * Copyright 2010, John Resig < * Dual licensed under the MIT or GPL Version 2 licenses. < * http://jquery.org/license > * Copyright 2010, John Resig, http://jquery.com/ > * Distributed in whole under the terms of the MIT license > * http://www.opensource.org/licenses/mit-license.php [...]	(invalid)
Baidu	24836 bytes	65b352e1ba79f0e2a3b1e014bc2571af	only whitespaces differ	January 7, 2015 @ 10:16

Note: only the MD5 hashes are shown to keep things simple.

Other Versions

Available jQuery versions at minime.stephan-brumme.com:

3.6.1, 3.6.0,
3.5.1, 3.5.0,
3.4.1, 3.4.0,
3.3.1, 3.3.0,
3.2.1, 3.2.0,
3.1.1, 3.1.0, 3.0.0,
2.2.4, 2.2.3, 2.2.2, 2.2.1, 2.2.0,
2.1.4, 2.1.3, 2.1.2, 2.1.1, 2.1.0,
2.0.3, 2.0.2, 2.0.1, 2.0.0,
1.12.4, 1.12.3, 1.12.2, 1.12.1, 1.12.0,
1.11.3, 1.11.2, 1.11.1, 1.11.0,
1.10.2, 1.10.1, 1.10.0,
1.9.1, 1.9.0,
1.8.3, 1.8.2, 1.8.1, 1.8.0,
1.7.2, 1.7.1, 1.7.0,
1.6.4, 1.6.3, 1.6.2, 1.6.1, 1.6,
1.5.2, 1.5.1, 1.5,
1.4.4, 1.4.3, 1.4.2, 1.4.1, 1.4,
1.3.2, 1.3.1, 1.3,
1.2.6, 1.2.5, 1.2.4, 1.2.3, 1.2.2, 1.2.1, 1.2,
1.1.4, 1.1.3, 1.1.2, 1.1.1, 1.1,
1.0.4, 1.0.3, 1.0.2, 1.0.1, 1.0

The project site contains an overview how well these versions were compressed.
Other interesting projects are AngularJS, BackboneJS, Bootstrap, D3, Dojo, Ember, Knockout, lodash, React, Socket.IO, ThreeJS, UnderscoreJS and Vue.

Changelog

Best Zopfli parameters so far:

Size	Improvement	Parameters	Found
23745 bytes	-2 bytes	zopfli --i100000 --mls8 --bsr16 --lazy --ohh	October 21, 2015 @ 12:03
23747 bytes	-2 bytes	zopfli --i10000 --mls8 --bsr16 --lazy --ohh	October 21, 2015 @ 11:32
23749 bytes	-5 bytes	zopfli --i1000 --mls8 --bsr16 --lazy --ohh	September 19, 2015 @ 23:44
23754 bytes	–	zopfli --i100 --mls8 --bsr16 --lazy --ohh	September 18, 2015 @ 16:18

If there are multiple parameter sets yielding the same compressed size, only the first one found is shown.

Most recent activity on July 20, 2020 @ 12:55.

Heatmaps

This Zopfli heatmap visualizes how compression changes when modifying the --bsr and --mls parameter.
Cell's contents is the best filesize achieved (in bytes, hover with mouse over cells to see number of iterations).

Good parameters are green, bad are red. The best and worst are bold as well.
The brightness of the blue background color indicates how many iterations were processed:
10,000 or 100,000.

bsr \ mls	2	4	8	16	32	64	128	256	512	1024	2048	4096	8192	16384	32768
bsr \ mls	2	4	8	16	32	64	128	256	512	1024	2048	4096	8192	16384	32768
2	23773	23773	23773	23773	23773	23774	23773	23774	23774	23776	23777	23777	23775	23773	23778
4	23778	23777	23778	23774	23779	23774	23773	23776	23773	23772	23777	23779	23780	23781	23781
6	23778	23776	23778	23778	23778	23773	23779	23773	23774	23773	23773	23780	23782	23783	23781
7	23779	23778	23772	23775	23776	23773	23777	23776	23774	23773	23773	23775	23774	23773	23774
8	23774	23774	23773	23774	23773	23774	23773	23774	23770	23776	23777	23773	23781	23779	23781
9	23776	23776	23778	23776	23775	23776	23774	23773	23774	23773	23774	23779	23782	23773	23784
10	23777	23777	23777	23778	23776	23777	23777	23778	23774	23778	23773	23773	23780	23772	23782
11	23776	23778	23776	23776	23774	23775	23774	23773	23770	23774	23774	23779	23773	23774	23776
12	23773	23772	23774	23772	23774	23774	23778	23774	23772	23773	23777	23772	23780	23773	23785
13	23776	23777	23774	23778	23774	23775	23777	23770	23773	23773	23777	23780	23780	23781	23780
14	23776	23776	23776	23778	23777	23777	23777	23778	23774	23778	23777	23779	23777	23773	23783
15	23777	23777	23776	23778	23775	23777	23778	23773	23774	23778	23773	23775	23780	23773	23776
16	23777	23777	23745	23774	23774	23775	23774	23773	23774	23773	23776	23774	23780	23779	23785
17	23777	23777	23777	23778	23774	23773	23779	23773	23774	23774	23773	23777	23780	23771	23785
18	23777	23772	23777	23777	23774	23775	23774	23778	23774	23773	23775	23780	23781	23773	23785
19	23777	23777	23776	23776	23776	23775	23779	23775	23773	23773	23773	23775	23772	23773	23780
20	23773	23774	23776	23775	23777	23776	23775	23774	23773	23773	23774	23773	23776	23774	23780
21	23773	23774	23775	23775	23773	23778	23776	23773	23773	23774	23774	23781	23780	23779	23779
22	23772	23772	23773	23774	23773	23778	23774	23774	23773	23774	23774	23773	23771	23772	23779
23	23774	23774	23776	23772	23774	23776	23776	23774	23773	23774	23777	23773	23780	23773	23783
25	23773	23774	23774	23774	23772	23777	23778	23774	23772	23774	23774	23774	23781	23774	23781
30	23773	23773	23773	23772	23776	23775	23779	23773	23774	23774	23777	23775	23780	23777	23781
40	23774	23774	23773	23776	23775	23775	23773	23774	23774	23774	23774	23780	23775	23774	23781

Due to the Monte Carlo design of my search algorithm, not all parameters have reached the same number of iterations yet:

Iterations	Min. Bytes	Reduction	Coverage
100	23754 bytes	–	100%
1,000	23749 bytes	-5 bytes	100%
10,000	23747 bytes	-2 bytes	100%
100,000	23745 bytes	-2 bytes	0.58%
1,000,000	–	–	–
10,000,000	–	–	–

KZIP has far less options available for tuning/optimization. I only played around with the number of blocks (parameter -n):

Blocks	Min. Bytes	Compared To Best Zopfli	Compared To Best KZIP
(any)	23841 bytes	+96 bytes (+0.40%)	+8 bytes
1	23841 bytes	+96 bytes (+0.40%)	+8 bytes
2	23871 bytes	+126 bytes (+0.53%)	+38 bytes
3	23860 bytes	+115 bytes (+0.48%)	+27 bytes
4	23835 bytes	+90 bytes (+0.38%)	+2 bytes
5	23833 bytes	+88 bytes (+0.37%)	–
6	23861 bytes	+116 bytes (+0.49%)	+28 bytes
7	23867 bytes	+122 bytes (+0.51%)	+34 bytes
8	23899 bytes	+154 bytes (+0.65%)	+66 bytes

Non-DEFLATE Algorithms

Archivers based on completely different compression algorithms often produce superior results.
Unfortunately, browsers only support gzip compression at the moment.
However, support for Brotli is constantly growing - for example, your browser actually supports it !

Algorithm	Program	Parameters	Size	Compared To Best Zopfli
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	19715 bytes	-4030 bytes (-16.97%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	20099 bytes	-3646 bytes (-15.35%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	20872 bytes	-2873 bytes (-12.10%)
Brotli (Wikipedia)	brotli	brotli -q 11	21942 bytes	-1803 bytes (-7.59%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	22643 bytes	-1102 bytes (-4.64%)
LZMA2 (Wikipedia)	xz	xz -9	23080 bytes	-665 bytes (-2.80%)
Zstandard (Wikipedia)	zstd	zstd -19	23466 bytes	-279 bytes (-1.17%)

Detailled Analysis

I wrote a DEFLATE decoder in Javascript. Click the button below to start a client-side analysis of the smallest gzipped files (may take a second):

Load and Parse Data

Notes: pigz is a fast open source multi-threaded implementation of gzip written by one of the original authors of gzip.
However, when using compression level 11, pigz actually switches to the slower Zopfli algorithm and isn't multi-threaded anymore.
KrzyMOD's extensions to Zopfli offer the highest level of configuration and is therefore used for my brute-force search.
Ken Silverman wrote the closed-source KZIP compression program and Jonathon Fowler ported it to Linux.
Defluff was created by Joachim Henke; DeflOpt is a tool by Ben Jos Walbeehm.

website made by Stephan Brumme in 2015 and still improving in 2026.
all timestamps are displayed in central european time. see my changelog.
no flash, not even images or external css files - and everything squeezed into a single html file.
which was handsomely compressed before releasing it into the wild internet - obviously.

please visit my homepage and my blog, too.
email: minime (at) stephan-brumme.com

All trademarks are property of their respective owners. You know, the boring legal stuff.