Choose a version:
32% The original file has 267194 bytes (260.9k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 86709 bytes (84.7k, 32%).

After GZIP compression these minified files vary in size:
Microsoft
  38719 bytes (37.8k)
CDN, direct link
cdnjs
  30332 bytes (29.6k)
CDN, direct link
gzip -6 (default)
  30140 bytes (29.4k)
local copy
cdnhttps
  30118 bytes (29.4k)
CDN, direct link
unpkg
  30118 bytes (29.4k)
CDN, direct link
gzip -9
  30090 bytes (29.4k)
local copy
jsdelivr
  30082 bytes (29.4k)
CDN, direct link
Google
  30080 bytes (29.4k)
CDN, direct link
7zip -mx=9 -tgzip
  29141 bytes (28.5k)
local copy
libdeflate -12
  29073 bytes (28.4k)
local copy
pigz -11 -n
  29045 bytes (28.4k)
local copy
kzip -s0 -rn -b2
  29043 bytes (28.4k)
local copy
Zopfli
  29027 bytes (28.3k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-3.1.1.min.js

You will automatically get the smallest jQuery 3.1.1 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 1053 bytes by using my jQuery 3.1.1 Zopfli version instead of the best available CDN (3.63% smaller than Google, 29027 vs. 30080 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 --mls512 --bsr40 --lazy --ohh

(found September 23, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 512  --mls512
block splitting recursion 40  --bsr40
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 http://code.jquery.com/jquery-3.1.1.min.js --location | md5sum
e071abda8fe61194711cfc2ab99fe104  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-3.1.1.min.zopfli.js.gz | md5sum
e071abda8fe61194711cfc2ab99fe104  -

SHA1:
curl --silent --compressed http://code.jquery.com/jquery-3.1.1.min.js --location | sha1sum
f647a6d37dc4ca055ced3cf64bbc1f490070acba  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-3.1.1.min.zopfli.js.gz | sha1sum
f647a6d37dc4ca055ced3cf64bbc1f490070acba  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 38719 bytes e071abda8fe61194711cfc2ab99fe104 September 27, 2016 @ 20:43
cdnjs 30332 bytes e071abda8fe61194711cfc2ab99fe104 September 23, 2016 @ 01:02
cdnhttps 30118 bytes e071abda8fe61194711cfc2ab99fe104 November 22, 2016 @ 16:35
unpkg 30118 bytes e071abda8fe61194711cfc2ab99fe104 September 23, 2016 @ 15:09
jsdelivr 30082 bytes e071abda8fe61194711cfc2ab99fe104 September 23, 2016 @ 01:05
Google 30080 bytes e071abda8fe61194711cfc2ab99fe104 September 28, 2016 @ 17:02

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
29027 bytes -1 byte zopfli --i1000000 --mls512 --bsr40 --lazy --ohh September 23, 2016 @ 21:43
29028 bytes -2 bytes zopfli --i100000 --mls512 --bsr10 --lazy --ohh September 23, 2016 @ 16:04
29030 bytes -2 bytes zopfli --i10000 --mls512 --bsr40 --lazy --ohh September 23, 2016 @ 15:22
29032 bytes -4 bytes zopfli --i10000 --mls32768 --bsr2 --lazy --ohh September 23, 2016 @ 15:19
29036 bytes zopfli --i100 --mls32768 --bsr2 --lazy --ohh September 23, 2016 @ 15:13

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

Most recent activity on March 22, 2017 @ 18:06.

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
29053 29052 29052 29053 29052 29048 29032 29055 29036 29040 29037 29034 29037 29036 29032
29053 29051 29052 29051 29053 29055 29047 29047 29050 29050 29037 29035 29037 29038 29038
29047 29049 29050 29049 29059 29051 29040 29033 29046 29043 29037 29036 29034 29038 29047
29068 29065 29051 29046 29066 29057 29057 29045 29045 29049 29046 29035 29036 29037 29036
29049 29049 29050 29052 29057 29043 29058 29033 29043 29040 29037 29036 29037 29038 29048
29046 29046 29049 29046 29050 29051 29057 29040 29027 29038 29036 29037 29037 29038 29048
29045 29047 29050 29050 29051 29056 29056 29047 29027 29043 29034 29036 29037 29038 29048
29047 29046 29049 29048 29058 29048 29047 29047 29046 29044 29047 29037 29037 29037 29048
29047 29046 29050 29050 29044 29047 29055 29047 29036 29038 29036 29036 29037 29037 29051
29048 29048 29051 29050 29057 29047 29056 29047 29046 29044 29037 29036 29037 29038 29036
29047 29048 29046 29050 29051 29047 29056 29047 29040 29049 29036 29035 29035 29038 29047
29047 29046 29050 29049 29056 29056 29047 29048 29045 29050 29037 29036 29036 29038 29048
29050 29047 29050 29049 29058 29048 29056 29033 29046 29043 29034 29037 29037 29037 29047
29047 29046 29050 29045 29057 29043 29058 29033 29046 29043 29037 29036 29037 29037 29051
29047 29046 29051 29049 29055 29048 29045 29047 29046 29043 29037 29037 29037 29037 29050
29049 29048 29049 29050 29058 29050 29056 29048 29027 29047 29037 29036 29037 29037 29048
29047 29047 29050 29051 29057 29043 29058 29047 29034 29049 29037 29036 29036 29038 29048
29047 29057 29051 29048 29059 29048 29046 29038 29046 29046 29036 29036 29035 29038 29033
29046 29050 29050 29055 29057 29057 29058 29047 29046 29045 29037 29037 29037 29038 29050
29047 29047 29050 29050 29051 29045 29057 29048 29047 29044 29045 29033 29037 29038 29047
29047 29047 29050 29048 29056 29048 29056 29047 29046 29045 29037 29036 29037 29037 29051
29047 29043 29050 29051 29056 29051 29056 29048 29046 29047 29037 29036 29037 29038 29048
29048 29046 29051 29047 29056 29050 29056 29040 29027 29049 29037 29037 29037 29037 29051

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 29036 bytes 100%
1,000 29035 bytes -1 byte 100%
10,000 29030 bytes -5 bytes 100%
100,000 29028 bytes -2 bytes 2.90%
1,000,000 29027 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
29139 bytes +112 bytes (+0.39%) +96 bytes
29139 bytes +112 bytes (+0.39%) +96 bytes
29043 bytes +16 bytes (+0.06%)
29052 bytes +25 bytes (+0.09%) +9 bytes
29061 bytes +34 bytes (+0.12%) +18 bytes
29110 bytes +83 bytes (+0.29%) +67 bytes
29141 bytes +114 bytes (+0.39%) +98 bytes
29185 bytes +158 bytes (+0.54%) +142 bytes
29216 bytes +189 bytes (+0.65%) +173 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 24108 bytes -4919 bytes (-16.95%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 24644 bytes -4383 bytes (-15.10%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 26107 bytes -2920 bytes (-10.06%)
Brotli (Wikipedia) brotli brotli -q 11 27251 bytes -1776 bytes (-6.12%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 27530 bytes -1497 bytes (-5.16%)
LZMA2 (Wikipedia) xz xz -9 28292 bytes -735 bytes (-2.53%)
ZSTD (Wikipedia) zstd zstd -19 28809 bytes -218 bytes (-0.75%)

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 2017.
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