Choose a version:
33% The original file has 258648 bytes (252.6k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 85659 bytes (83.7k, 33%).

After GZIP compression these minified files vary in size:
Microsoft
  38405 bytes (37.5k)
CDN
Boot
  34920 bytes (34.1k)
CDN
cdnjs
  30130 bytes (29.4k)
CDN
gzip -6 (default)
  29943 bytes (29.2k)
local copy
cdnhttps
  29937 bytes (29.2k)
CDN
unpkg
  29937 bytes (29.2k)
CDN
gzip -9
  29901 bytes (29.2k)
local copy
Google
  29893 bytes (29.2k)
CDN
jsdelivr
  29888 bytes (29.2k)
CDN
7zip -mx=9 -tgzip
  28937 bytes (28.3k)
local copy
libdeflate -12
  28873 bytes (28.2k)
local copy
Yandex
  28869 bytes (28.2k)
CDN
pigz -11 -n
  28862 bytes (28.2k)
local copy
kzip -s0 -rn -b2
  28848 bytes (28.2k)
local copy
Zopfli
  28825 bytes (28.1k)
local copy
Zopfli (defluff)
  28824 bytes (28.1k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-2.2.3.min.js

You will automatically get the smallest jQuery 2.2.3 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 44 bytes by using my jQuery 2.2.3 Zopfli version instead of the best available CDN (0.15% smaller than Yandex, 28825 vs. 28869 bytes):
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 --i10000000 --mb8 --mls8192 --bsr6 --lazy --ohh

(found April 9, 2016)
Description Value Parameter
iterations 10000000  --i10000000
maximum blocks 8  --mb8
maximum length score 8192  --mls8192
block splitting recursion 6  --bsr6
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 1 more byte (28824 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://code.jquery.com/jquery-2.2.3.min.js --location | md5sum
33cabfa15c1060aaa3d207c653afb1ee  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-2.2.3.min.zopfli.js.gz | md5sum
33cabfa15c1060aaa3d207c653afb1ee  -

SHA1:
curl --silent --compressed http://code.jquery.com/jquery-2.2.3.min.js --location | sha1sum
e3dbb65f2b541d842b50d37304b0102a2d5f2387  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-2.2.3.min.zopfli.js.gz | sha1sum
e3dbb65f2b541d842b50d37304b0102a2d5f2387  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 38405 bytes 33cabfa15c1060aaa3d207c653afb1ee April 12, 2016 @ 19:19
Boot 34920 bytes 33cabfa15c1060aaa3d207c653afb1ee May 4, 2016 @ 09:17
cdnjs 30130 bytes 33cabfa15c1060aaa3d207c653afb1ee April 6, 2016 @ 05:46
cdnhttps 29937 bytes 33cabfa15c1060aaa3d207c653afb1ee November 22, 2016 @ 16:35
unpkg 29937 bytes 33cabfa15c1060aaa3d207c653afb1ee July 11, 2016 @ 15:38
Google 29893 bytes 33cabfa15c1060aaa3d207c653afb1ee May 13, 2016 @ 13:12
jsdelivr 29888 bytes 33cabfa15c1060aaa3d207c653afb1ee April 5, 2016 @ 22:39
Yandex 28869 bytes 33cabfa15c1060aaa3d207c653afb1ee (invalid)

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

Other Versions

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

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
28825 bytes -1 byte zopfli --i10000000 --mls8192 --bsr6 --lazy --ohh April 9, 2016 @ 20:24
28826 bytes -1 byte zopfli --i1000000 --mls8192 --bsr6 --lazy --ohh April 6, 2016 @ 21:10
28827 bytes -1 byte zopfli --i1000000 --mls256 --bsr23 --lazy --ohh April 6, 2016 @ 21:10
28828 bytes -2 bytes zopfli --i100000 --mls256 --bsr23 --lazy --ohh April 6, 2016 @ 13:42
28830 bytes -4 bytes zopfli --i10000 --mls8 --bsr16 --lazy --ohh April 6, 2016 @ 10:43
28834 bytes -1 byte zopfli --i1000 --mls8 --bsr16 --lazy --ohh April 6, 2016 @ 10:41
28835 bytes -4 bytes zopfli --i1000 --mls8192 --bsr6 --lazy --ohh April 6, 2016 @ 10:40
28839 bytes zopfli --i100 --mls2 --bsr6 --lazy --ohh April 6, 2016 @ 10:34

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

Most recent activity on November 22, 2016 @ 16:35.

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, 1,000,000 or 10,000,000.
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
28838 28840 28838 28839 28839 28840 28842 28841 28838 28840 28843 28843 28840 28847 28862
28845 28846 28845 28844 28847 28840 28846 28845 28843 28845 28839 28840 28839 28839 28844
28834 28843 28836 28841 28840 28841 28844 28845 28842 28843 28839 28838 28825 28838 28844
28844 28844 28836 28853 28849 28845 28843 28844 28844 28843 28838 28838 28839 28838 28839
28844 28844 28830 28835 28839 28843 28844 28840 28841 28841 28838 28838 28838 28838 28839
28844 28836 28842 28845 28846 28840 28844 28843 28842 28845 28838 28838 28839 28838 28837
28844 28843 28836 28853 28843 28857 28843 28843 28845 28843 28837 28838 28838 28838 28838
28844 28843 28843 28843 28843 28844 28844 28837 28842 28842 28836 28838 28838 28838 28837
28843 28843 28836 28856 28843 28858 28844 28843 28842 28840 28835 28838 28839 28838 28837
28844 28844 28837 28838 28844 28858 28844 28843 28842 28843 28838 28838 28839 28838 28836
28844 28843 28836 28843 28843 28837 28829 28844 28842 28843 28838 28838 28837 28838 28836
28844 28844 28834 28846 28843 28844 28844 28843 28844 28843 28835 28838 28838 28838 28843
28844 28831 28830 28840 28846 28856 28844 28845 28844 28843 28835 28838 28838 28839 28836
28844 28841 28842 28844 28848 28856 28844 28843 28843 28844 28835 28838 28838 28838 28837
28844 28840 28841 28853 28843 28834 28844 28835 28843 28843 28837 28838 28838 28838 28835
28844 28843 28836 28853 28836 28844 28844 28843 28845 28843 28838 28838 28838 28838 28835
28842 28843 28841 28852 28847 28841 28844 28843 28842 28843 28836 28838 28838 28839 28837
28844 28843 28841 28846 28844 28844 28843 28843 28844 28844 28838 28838 28838 28839 28839
28844 28843 28837 28853 28843 28841 28843 28844 28845 28843 28837 28838 28837 28838 28838
28844 28841 28841 28853 28843 28842 28844 28827 28843 28843 28838 28838 28837 28840 28836
28842 28843 28840 28846 28844 28837 28844 28843 28843 28843 28838 28838 28838 28839 28836
28844 28836 28836 28853 28843 28858 28844 28843 28842 28835 28838 28838 28837 28838 28837
28844 28844 28834 28844 28836 28844 28844 28843 28840 28843 28837 28838 28838 28838 28837

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 28839 bytes 100%
1,000 28834 bytes -5 bytes 100%
10,000 28830 bytes -4 bytes 100%
100,000 28828 bytes -2 bytes 2.32%
1,000,000 28826 bytes -2 bytes 0.58%
10,000,000 28825 bytes -1 byte 0.29%

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
28944 bytes +119 bytes (+0.41%) +96 bytes
28944 bytes +119 bytes (+0.41%) +96 bytes
28848 bytes +23 bytes (+0.08%)
28860 bytes +35 bytes (+0.12%) +12 bytes
28869 bytes +44 bytes (+0.15%) +21 bytes
28903 bytes +78 bytes (+0.27%) +55 bytes
28938 bytes +113 bytes (+0.39%) +90 bytes
28989 bytes +164 bytes (+0.57%) +141 bytes
29015 bytes +190 bytes (+0.66%) +167 bytes

Non-DEFLATE Algorithms

Archivers based on completely different compression algorithms often produce superior results.
Unfortunately, browsers only support gzip compression at the moment.
Algorithm Program Parameters Size Compared To Best Zopfli
ZPAQ (Wikipedia) zpaq zpaq -method 69 23957 bytes -4868 bytes (-16.89%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 24455 bytes -4370 bytes (-15.16%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 25913 bytes -2912 bytes (-10.10%)
Brotli (Wikipedia) brotli brotli -q 11 27022 bytes -1803 bytes (-6.25%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 27313 bytes -1512 bytes (-5.25%)
LZMA2 (Wikipedia) xz xz -9 28096 bytes -729 bytes (-2.53%)
ZSTD (Wikipedia) zstd zstd -19 28621 bytes -204 bytes (-0.71%)

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):


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 2018.
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