Choose a version:
33% The original file has 263268 bytes (257.1k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 86341 bytes (84.3k, 33%).

After GZIP compression these minified files vary in size:
Microsoft
  38617 bytes (37.7k)
CDN
Boot
  35040 bytes (34.2k)
CDN
cdnjs
  30248 bytes (29.5k)
CDN
gzip -6 (default)
  30063 bytes (29.4k)
local copy
cdnhttps
  30059 bytes (29.4k)
CDN
unpkg
  30059 bytes (29.4k)
CDN
gzip -9
  30015 bytes (29.3k)
local copy
jsdelivr
  30010 bytes (29.3k)
CDN
Google
  30005 bytes (29.3k)
CDN
7zip -mx=9 -tgzip
  29082 bytes (28.4k)
local copy
libdeflate -12
  29010 bytes (28.3k)
local copy
pigz -11 -n
  29006 bytes (28.3k)
local copy
kzip -s0 -rn -b2
  28980 bytes (28.3k)
local copy
Zopfli
  28964 bytes (28.3k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-3.0.0.min.js (or via HTTPS)

You will automatically get the smallest jQuery 3.0.0 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 1041 bytes by using my jQuery 3.0.0 Zopfli version instead of the best available CDN (3.59% smaller than Google, 28964 vs. 30005 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 --i1000000 --mb8 --mls16384 --bsr4 --lazy --ohh

(found June 10, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 16384  --mls16384
block splitting recursion 4  --bsr4
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-3.0.0.min.js --location | md5sum
d0212568ce69457081dacf84e327fa5c  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-3.0.0.min.zopfli.js.gz | md5sum
d0212568ce69457081dacf84e327fa5c  -

SHA1:
curl --silent --compressed https://code.jquery.com/jquery-3.0.0.min.js --location | sha1sum
d6702a1af0378b2342f6a0692e77c169f580aed7  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-3.0.0.min.zopfli.js.gz | sha1sum
d6702a1af0378b2342f6a0692e77c169f580aed7  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 38617 bytes d0212568ce69457081dacf84e327fa5c June 16, 2016 @ 21:10
Boot 35040 bytes d0212568ce69457081dacf84e327fa5c June 10, 2016 @ 06:42
cdnjs 30248 bytes d0212568ce69457081dacf84e327fa5c June 9, 2016 @ 21:01
cdnhttps 30059 bytes d0212568ce69457081dacf84e327fa5c November 22, 2016 @ 16:35
unpkg 30059 bytes d0212568ce69457081dacf84e327fa5c July 11, 2016 @ 15:38
jsdelivr 30010 bytes d0212568ce69457081dacf84e327fa5c June 9, 2016 @ 21:04
Google 30005 bytes d0212568ce69457081dacf84e327fa5c June 11, 2016 @ 02:51

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

Other Versions

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

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
28964 bytes -1 byte zopfli --i1000000 --mls16384 --bsr4 --lazy --ohh June 10, 2016 @ 22:58
28965 bytes -1 byte zopfli --i100000 --mls8192 --bsr23 --lazy --ohh June 10, 2016 @ 00:35
28966 bytes -3 bytes zopfli --i100000 --mls8192 --bsr7 --lazy --ohh June 10, 2016 @ 00:02
28969 bytes -3 bytes zopfli --i10000 --mls8192 --bsr23 --lazy --ohh June 9, 2016 @ 23:19
28972 bytes -1 byte zopfli --i1000 --mls8192 --bsr9 --lazy --ohh June 9, 2016 @ 23:13
28973 bytes zopfli --i100 --mls2048 --bsr8 --lazy --ohh June 9, 2016 @ 22:41

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 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
28986 28987 28986 28986 28987 28987 28986 28988 28989 28992 28978 28979 28973 28970 28982
28986 28987 28984 28988 28986 28990 28996 28983 28985 28985 28983 28973 28973 28964 28985
28983 28983 29001 28981 28985 28991 28981 28981 28981 28981 28982 28973 28972 28976 28986
28984 28980 28983 28999 28984 28999 28982 28982 28982 28983 28980 28972 28966 28972 28983
28982 28986 28981 28985 28992 28989 28981 28981 28981 28989 28970 28969 28972 28974 28984
28986 28986 28980 28986 28992 28988 28981 28983 28986 28986 28981 28972 28969 28973 28983
28981 28981 29003 28984 28982 28991 28981 28981 28981 28982 28985 28972 28972 28973 28985
28985 28982 28981 28981 28983 28999 28981 28981 28983 28983 28985 28972 28969 28975 28983
28982 28984 28983 28981 28991 28991 28981 28981 28981 28981 28970 28972 28966 28972 28984
28999 28981 28980 29002 28983 29004 28981 28981 28981 28980 28980 28972 28971 28975 28985
28981 28982 28984 28986 28994 28993 28981 28981 28981 28980 28969 28972 28966 28972 28984
28981 28980 28980 28985 28984 29002 28981 28982 28981 28980 28981 28972 28969 28975 28983
28985 28982 28984 28985 28984 28986 28981 28981 28982 28980 28981 28969 28979 28973 28987
28981 28983 28982 28981 28982 28984 28981 28985 28981 28981 28981 28972 28971 28975 28984
28981 28981 28981 28982 28984 28986 28981 28981 28981 28980 28970 28970 28970 28975 28983
28982 28980 28982 28985 28987 29000 28981 28981 28981 28980 28980 28972 28971 28973 28984
28984 28985 28982 28984 28982 28986 28981 28981 28981 28982 28982 28970 28972 28973 28983
28982 28982 28981 28981 28983 28990 28981 28982 28981 28981 28980 28972 28971 28971 28983
28987 28982 29002 28983 28983 28992 28981 28982 28981 28980 28981 28972 28971 28973 28984
28985 28984 28982 28981 29000 29002 28981 28981 28981 28981 28981 28970 28965 28975 28984
28986 28982 28982 28986 28983 28993 28981 28981 28986 28975 28966 28972 28971 28972 28984
29001 28981 28980 28981 28981 28991 28985 28985 28981 28980 28981 28972 28969 28972 28985
28981 28982 28982 28985 28981 28991 28981 28981 28981 28980 28980 28972 28971 28976 28983

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 28973 bytes 100%
1,000 28971 bytes -2 bytes 100%
10,000 28967 bytes -4 bytes 100%
100,000 28965 bytes -2 bytes 1.74%
1,000,000 28964 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
29081 bytes +117 bytes (+0.40%) +101 bytes
29085 bytes +121 bytes (+0.42%) +105 bytes
28980 bytes +16 bytes (+0.06%)
28999 bytes +35 bytes (+0.12%) +19 bytes
29003 bytes +39 bytes (+0.13%) +23 bytes
29047 bytes +83 bytes (+0.29%) +67 bytes
29083 bytes +119 bytes (+0.41%) +103 bytes
29122 bytes +158 bytes (+0.55%) +142 bytes
29149 bytes +185 bytes (+0.64%) +169 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 24027 bytes -4937 bytes (-17.05%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 24597 bytes -4367 bytes (-15.08%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 26037 bytes -2927 bytes (-10.11%)
Brotli (Wikipedia) brotli brotli -q 11 27148 bytes -1816 bytes (-6.27%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 27488 bytes -1476 bytes (-5.10%)
LZMA2 (Wikipedia) xz xz -9 28240 bytes -724 bytes (-2.50%)
Zstandard (Wikipedia) zstd zstd -19 28762 bytes -202 bytes (-0.70%)

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