Choose a version:
33% The original file has 263767 bytes (257.6k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 86351 bytes (84.3k, 33%).

After GZIP compression these minified files vary in size:
Microsoft
  38649 bytes (37.7k)
CDN
Boot
  35038 bytes (34.2k)
CDN
cdnjs
  30277 bytes (29.6k)
CDN
gzip -6 (default)
  30090 bytes (29.4k)
local copy
cdnhttps
  30077 bytes (29.4k)
CDN
unpkg
  30077 bytes (29.4k)
CDN
gzip -9
  30039 bytes (29.3k)
local copy
jsdelivr
  30033 bytes (29.3k)
CDN
Google
  30029 bytes (29.3k)
CDN
Sina
  30029 bytes (29.3k)
CDN
7zip -mx=9 -tgzip
  29096 bytes (28.4k)
local copy
libdeflate -12
  29040 bytes (28.4k)
local copy
kzip -s0 -rn -b2
  29006 bytes (28.3k)
local copy
pigz -11 -n
  29004 bytes (28.3k)
local copy
Zopfli
  28988 bytes (28.3k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-3.1.0.min.js (or via HTTPS)

You will automatically get the smallest jQuery 3.1.0 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 3.1.0 Zopfli version instead of the best available CDN (3.59% smaller than Sina, 28988 vs. 30029 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 --mls4096 --bsr17 --lazy --ohh

(found July 8, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 4096  --mls4096
block splitting recursion 17  --bsr17
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-3.1.0.min.js --location | md5sum
05e51b1db558320f1939f9789ccf5c8f  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-3.1.0.min.zopfli.js.gz | md5sum
05e51b1db558320f1939f9789ccf5c8f  -

SHA1:
curl --silent --compressed https://code.jquery.com/jquery-3.1.0.min.js --location | sha1sum
c72c1735b4d903d90dd51225ebefb8c74ebbc51f  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-3.1.0.min.zopfli.js.gz | sha1sum
c72c1735b4d903d90dd51225ebefb8c74ebbc51f  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 38649 bytes 05e51b1db558320f1939f9789ccf5c8f July 15, 2016 @ 19:03
Boot 35038 bytes 05e51b1db558320f1939f9789ccf5c8f July 8, 2016 @ 06:57
cdnjs 30277 bytes 05e51b1db558320f1939f9789ccf5c8f July 8, 2016 @ 00:01
cdnhttps 30077 bytes 05e51b1db558320f1939f9789ccf5c8f November 22, 2016 @ 16:35
unpkg 30077 bytes 05e51b1db558320f1939f9789ccf5c8f July 11, 2016 @ 15:38
jsdelivr 30033 bytes 05e51b1db558320f1939f9789ccf5c8f July 8, 2016 @ 00:04
Google 30029 bytes 05e51b1db558320f1939f9789ccf5c8f July 12, 2016 @ 09:12
Sina 30029 bytes 05e51b1db558320f1939f9789ccf5c8f September 9, 2016 @ 10:47

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
28988 bytes -1 byte zopfli --i1000000 --mls4096 --bsr17 --lazy --ohh July 8, 2016 @ 19:05
28989 bytes -1 byte zopfli --i100000 --mls4096 --bsr40 --lazy --ohh July 8, 2016 @ 11:40
28990 bytes -2 bytes zopfli --i100000 --mls16384 --bsr2 --lazy --ohh July 8, 2016 @ 11:23
28992 bytes -1 byte zopfli --i10000 --mls16384 --bsr2 --lazy --ohh July 8, 2016 @ 11:02
28993 bytes -2 bytes zopfli --i10000 --mls8192 --bsr9 --lazy --ohh July 8, 2016 @ 11:00
28995 bytes -1 byte zopfli --i1000 --mls16384 --bsr2 --lazy --ohh July 8, 2016 @ 10:58
28996 bytes -1 byte zopfli --i1000 --mls8192 --bsr6 --lazy --ohh July 8, 2016 @ 10:57
28997 bytes -1 byte zopfli --i1000 --mls16384 --bsr4 --lazy --ohh July 8, 2016 @ 10:56
28998 bytes zopfli --i100 --mls8192 --bsr13 --lazy --ohh July 8, 2016 @ 10:53

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
29014 29012 29012 29013 29014 29016 29016 29016 29000 28999 28999 28996 28996 28990 29009
29013 29011 29012 29012 29013 29014 29012 29011 29010 29011 28997 28997 28997 28996 29022
29019 29001 29001 29014 29013 29012 29017 29006 29005 29006 28995 29000 28990 29002 29009
29012 29017 29018 29011 29012 29012 29026 29007 29008 29009 28995 28989 28997 28999 29010
29004 29019 29018 29011 29013 29014 29015 29015 29000 29002 28996 28996 29001 29000 29008
29009 29010 29006 29011 29014 29013 29020 29013 29007 28996 28996 28994 28990 29003 29009
29007 29004 29021 29010 29014 29024 29015 29006 29012 28996 28995 29001 29001 29006 29011
29013 29009 29019 29010 29013 29026 29028 29006 29006 29009 28996 29002 28997 29006 29018
29012 29009 29012 29008 29017 29024 29029 29005 29006 28995 28996 28995 28996 28997 29018
29019 29018 29018 29010 29018 29024 29027 29013 28995 28995 28996 28990 28990 29003 29019
29013 29009 29010 29010 29012 29025 29026 29006 29001 28995 28996 28994 28996 28997 29010
29006 29015 29001 29011 29012 29012 29026 29007 29006 29009 28995 28994 28994 28997 29011
29011 29008 29022 29007 29004 29014 29014 29006 29002 29009 28995 28988 28990 29001 28995
29012 29009 29018 29005 29013 29023 29028 29006 29012 28996 28995 28988 28997 29006 29020
29010 29006 29019 29011 29014 29013 29015 29006 29002 29009 28996 28994 28997 29001 29010
29014 29007 29009 29011 29008 29006 29026 29007 29002 29009 28996 28995 28994 28997 29021
29004 29010 29020 29012 29012 29014 29026 29015 29002 28996 28996 28994 28990 29001 29008
29011 29010 29018 29012 29013 29014 29028 29006 29012 29009 28996 28994 28990 29006 29010
29011 29008 29019 29012 29012 29014 29027 29006 29013 28996 29006 28995 28996 28997 29012
29004 29012 29017 29012 29014 29012 29027 29009 28996 29009 28996 28995 28999 29006 29011
29014 29009 29013 29011 29014 29024 29027 29006 29013 29009 28996 28995 28998 28996 29011
29006 29004 29012 29011 29013 29014 29027 29007 29012 29008 28996 28990 28990 29001 29010
29016 29010 29018 29010 29013 29012 29017 29013 29013 29009 29006 28989 28990 28996 29012

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 28998 bytes 100%
1,000 28995 bytes -3 bytes 100%
10,000 28992 bytes -3 bytes 100%
100,000 28989 bytes -3 bytes 4.35%
1,000,000 28988 bytes -1 byte 1.16%
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
29102 bytes +114 bytes (+0.39%) +96 bytes
29102 bytes +114 bytes (+0.39%) +96 bytes
29006 bytes +18 bytes (+0.06%)
29020 bytes +32 bytes (+0.11%) +14 bytes
29026 bytes +38 bytes (+0.13%) +20 bytes
29075 bytes +87 bytes (+0.30%) +69 bytes
29113 bytes +125 bytes (+0.43%) +107 bytes
29148 bytes +160 bytes (+0.55%) +142 bytes
29175 bytes +187 bytes (+0.65%) +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 24037 bytes -4951 bytes (-17.08%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 24617 bytes -4371 bytes (-15.08%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 26049 bytes -2939 bytes (-10.14%)
Brotli (Wikipedia) brotli brotli -q 11 27176 bytes -1812 bytes (-6.25%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 27485 bytes -1503 bytes (-5.18%)
LZMA2 (Wikipedia) xz xz -9 28244 bytes -744 bytes (-2.57%)
Zstandard (Wikipedia) zstd zstd -19 28777 bytes -211 bytes (-0.73%)

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