jQuery 1.12.3 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 293650 bytes (286.8k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 97180 bytes (94.9k, 33%).

After GZIP compression these minified files vary in size:

Microsoft	43375 bytes (42.4k)	CDN
Boot	39459 bytes (38.5k)	CDN
cdnjs	34033 bytes (33.2k)	CDN
gzip -6 (default)	33849 bytes (33.1k)	local copy
jsdelivr	33828 bytes (33.0k)	CDN
unpkg	33820 bytes (33.0k)	CDN
Google	33794 bytes (33.0k)	CDN
gzip -9	33794 bytes (33.0k)	local copy
7zip -mx=9 -tgzip	32677 bytes (31.9k)	local copy
libdeflate -12	32629 bytes (31.9k)	local copy
Yandex	32604 bytes (31.8k)	CDN
zultra	32602 bytes (31.8k)	local copy
pigz -11 -n	32596 bytes (31.8k)	local copy
kzip -s0 -rn -b2	32588 bytes (31.8k)	local copy
Zopfli	32575 bytes (31.8k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-1.12.3.min.js (or via HTTPS)

You will automatically get the smallest jQuery 1.12.3 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 29 bytes by using my jQuery 1.12.3 Zopfli version instead of the best available CDN (0.09% smaller than Yandex, 32575 vs. 32604 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 --i1000000 --mb8 --mls2 --bsr18 --lazy --ohh

(found April 6, 2016)

Description	Value	Parameter
iterations	1000000	--i1000000
maximum blocks	8	--mb8
maximum length score	2	--mls2
block splitting recursion	18	--bsr18
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

Verify file integrity

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

MD5:
curl --silent --compressed https://code.jquery.com/jquery-1.12.3.min.js --location | md5sum
c07f2267a050732b752cc3e7a06850ac -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.12.3.min.zopfli.js.gz | md5sum
c07f2267a050732b752cc3e7a06850ac -

SHA1:
curl --silent --compressed https://code.jquery.com/jquery-1.12.3.min.js --location | sha1sum
220dad6750fba4898e10b8d9b78ca46f4f774544 -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.12.3.min.zopfli.js.gz | sha1sum
220dad6750fba4898e10b8d9b78ca46f4f774544 -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Microsoft	43375 bytes	c07f2267a050732b752cc3e7a06850ac	April 12, 2016 @ 19:18
Boot	39459 bytes	c07f2267a050732b752cc3e7a06850ac	May 4, 2016 @ 09:17
cdnjs	34033 bytes	c07f2267a050732b752cc3e7a06850ac	April 6, 2016 @ 05:46
jsdelivr	33828 bytes	c07f2267a050732b752cc3e7a06850ac	April 5, 2016 @ 22:38
unpkg	33820 bytes	c07f2267a050732b752cc3e7a06850ac	July 11, 2016 @ 15:39
Google	33794 bytes	c07f2267a050732b752cc3e7a06850ac	May 13, 2016 @ 13:12
Yandex	32604 bytes	c07f2267a050732b752cc3e7a06850ac	(invalid)

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
32575 bytes	-1 byte	zopfli --i1000000 --mls2 --bsr18 --lazy --ohh	April 6, 2016 @ 21:32
32576 bytes	-3 bytes	zopfli --i100000 --mls2 --bsr18 --lazy --ohh	April 6, 2016 @ 11:15
32579 bytes	-2 bytes	zopfli --i10000 --mls2 --bsr18 --lazy --ohh	April 6, 2016 @ 10:43
32581 bytes	-6 bytes	zopfli --i1000 --mls2 --bsr18 --lazy --ohh	April 6, 2016 @ 10:40
32587 bytes	–	zopfli --i100 --mls2 --bsr18 --lazy --ohh	April 6, 2016 @ 10:36

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 @ 12:53.

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, 100,000 or 1,000,000.

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	32590	32590	32589	32589	32590	32588	32587	32591	32591	32591	32590	32592	32596	32596	32595
4	32585	32583	32584	32582	32583	32582	32584	32586	32586	32582	32585	32582	32598	32584	32585
6	32589	32587	32584	32589	32588	32582	32591	32588	32592	32591	32585	32582	32583	32583	32581
7	32590	32588	32587	32593	32588	32583	32587	32583	32588	32589	32583	32584	32585	32582	32581
8	32590	32581	32590	32589	32590	32588	32588	32590	32591	32591	32578	32582	32583	32584	32580
9	32581	32582	32583	32581	32588	32589	32590	32588	32590	32589	32582	32584	32581	32585	32583
10	32580	32582	32582	32580	32589	32588	32588	32587	32587	32587	32582	32585	32582	32583	32581
11	32585	32581	32586	32581	32590	32581	32587	32587	32589	32590	32580	32580	32581	32584	32580
12	32588	32588	32587	32588	32588	32588	32587	32587	32587	32584	32580	32584	32581	32584	32583
13	32575	32581	32582	32580	32588	32588	32583	32588	32587	32587	32584	32584	32581	32583	32580
14	32591	32581	32581	32587	32588	32588	32587	32587	32588	32591	32578	32584	32582	32583	32581
15	32581	32581	32580	32579	32582	32583	32588	32583	32587	32586	32582	32584	32582	32583	32581
16	32581	32581	32581	32584	32588	32584	32588	32587	32587	32587	32580	32584	32582	32582	32581
17	32581	32582	32582	32583	32591	32588	32588	32587	32588	32590	32587	32584	32581	32585	32582
18	32575	32578	32581	32587	32588	32588	32582	32587	32588	32589	32582	32585	32578	32584	32582
19	32581	32581	32580	32587	32588	32581	32582	32587	32588	32587	32585	32584	32582	32583	32583
20	32591	32578	32582	32588	32588	32582	32582	32589	32590	32584	32582	32584	32584	32584	32580
21	32590	32588	32582	32580	32587	32582	32589	32588	32588	32585	32577	32585	32581	32584	32581
22	32581	32581	32583	32587	32588	32584	32587	32581	32588	32587	32581	32583	32583	32583	32580
23	32582	32579	32581	32581	32588	32581	32587	32589	32587	32589	32580	32584	32582	32584	32586
25	32591	32588	32581	32588	32588	32583	32588	32582	32589	32586	32582	32584	32582	32584	32582
30	32590	32588	32581	32587	32589	32583	32587	32588	32587	32587	32580	32584	32582	32585	32582
40	32581	32581	32581	32580	32581	32583	32587	32587	32587	32587	32587	32584	32584	32584	32580

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	32587 bytes	–	100%
1,000	32581 bytes	-6 bytes	100%
10,000	32579 bytes	-2 bytes	100%
100,000	32576 bytes	-3 bytes	2.90%
1,000,000	32575 bytes	-1 byte	0.58%
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)	32680 bytes	+105 bytes (+0.32%)	+92 bytes
1	32680 bytes	+105 bytes (+0.32%)	+92 bytes
2	32588 bytes	+13 bytes (+0.04%)	–
3	32602 bytes	+27 bytes (+0.08%)	+14 bytes
4	32607 bytes	+32 bytes (+0.10%)	+19 bytes
5	32643 bytes	+68 bytes (+0.21%)	+55 bytes
6	32674 bytes	+99 bytes (+0.30%)	+86 bytes
7	32713 bytes	+138 bytes (+0.42%)	+125 bytes
8	32752 bytes	+177 bytes (+0.54%)	+164 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	26653 bytes	-5922 bytes (-18.18%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	27401 bytes	-5174 bytes (-15.88%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	29102 bytes	-3473 bytes (-10.66%)
Brotli (Wikipedia)	brotli	brotli -q 11	30366 bytes	-2209 bytes (-6.78%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	30669 bytes	-1906 bytes (-5.85%)
LZMA2 (Wikipedia)	xz	xz -9	31524 bytes	-1051 bytes (-3.23%)
Zstandard (Wikipedia)	zstd	zstd -19	32116 bytes	-459 bytes (-1.41%)

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.