Choose a version:
38% The original file has 238009 bytes (232.4k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 91626 bytes (89.5k, 38%).

After GZIP compression these minified files vary in size:
Microsoft
  40868 bytes (39.9k)
CDN
Boot
  37123 bytes (36.3k)
CDN
Baidu
  32357 bytes (31.6k)
CDN
cdnjs
  32350 bytes (31.6k)
CDN
gzip -6 (default)
  32127 bytes (31.4k)
local copy
Google
  32107 bytes (31.4k)
CDN
cdnhttps
  32107 bytes (31.4k)
CDN
gzip -9
  32063 bytes (31.3k)
local copy
kzip -s0 -rn -b0
  30962 bytes (30.2k)
local copy
7zip -mx=9 -tgzip
  30941 bytes (30.2k)
local copy
libdeflate -12
  30899 bytes (30.2k)
local copy
Yandex
  30898 bytes (30.2k)
CDN
pigz -11 -n
  30882 bytes (30.2k)
local copy
Zopfli
  30857 bytes (30.1k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-1.6.3.min.js

You will automatically get the smallest jQuery 1.6.3 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 41 bytes by using my jQuery 1.6.3 Zopfli version instead of the best available CDN (0.13% smaller than Yandex, 30857 vs. 30898 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 --i100000 --mb8 --mls4096 --bsr9 --lazy --ohh

(found January 8, 2016)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 4096  --mls4096
block splitting recursion 9  --bsr9
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-1.6.3.min.js --location | md5sum
685f048a4660c3852169702a83508e85  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-1.6.3.min.zopfli.js.gz | md5sum
685f048a4660c3852169702a83508e85  -

SHA1:
curl --silent --compressed http://code.jquery.com/jquery-1.6.3.min.js --location | sha1sum
0cf62d1dd0c483b423f5dfd655f62d03ed2668f6  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-1.6.3.min.zopfli.js.gz | sha1sum
0cf62d1dd0c483b423f5dfd655f62d03ed2668f6  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 40868 bytes 685f048a4660c3852169702a83508e85 (invalid)
Boot 37123 bytes 685f048a4660c3852169702a83508e85 May 4, 2016 @ 09:17
cdnjs 32350 bytes 685f048a4660c3852169702a83508e85 June 22, 2016 @ 22:04
Google 32107 bytes 685f048a4660c3852169702a83508e85 (invalid)
cdnhttps 32107 bytes 685f048a4660c3852169702a83508e85 November 24, 2016 @ 16:42
Yandex 30898 bytes 685f048a4660c3852169702a83508e85 June 15, 2015 @ 21:17

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Baidu 32357 bytes 29312d8b0d2e5a331161b2f3d89a39e2 only whitespaces differ January 7, 2015 @ 10:16

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
30857 bytes -1 byte zopfli --i100000 --mls4096 --bsr9 --lazy --ohh January 8, 2016 @ 09:50
30858 bytes -1 byte zopfli --i100000 --mls4096 --bsr4 --lazy --ohh September 2, 2015 @ 00:58
30859 bytes -3 bytes zopfli --i10000 --mls4096 --bsr4 --lazy --ohh September 1, 2015 @ 21:25
30862 bytes -3 bytes zopfli --i1000 --mls4096 --bsr4 --lazy --ohh September 1, 2015 @ 20:37
30865 bytes -9 bytes zopfli --i1000 --mls8192 --bsr12 --lazy --ohh September 1, 2015 @ 20:37
30874 bytes zopfli --i100 --mls4096 --bsr9 --lazy --ohh September 1, 2015 @ 20:19

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

Most recent activity on November 24, 2016 @ 16:42.

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 or 100,000.
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
30875 30875 30873 30875 30875 30882 30876 30877 30876 30877 30873 30866 30865 30864 30870
30871 30868 30868 30867 30867 30868 30869 30872 30872 30873 30874 30858 30864 30873 30875
30865 30866 30868 30865 30865 30870 30865 30865 30867 30867 30866 30866 30866 30865 30866
30874 30867 30866 30870 30867 30866 30868 30867 30865 30865 30870 30864 30861 30868 30873
30874 30874 30868 30870 30866 30866 30873 30867 30867 30866 30866 30866 30863 30868 30869
30866 30867 30868 30867 30867 30866 30868 30872 30867 30867 30874 30857 30872 30868 30869
30865 30867 30868 30870 30866 30866 30868 30866 30867 30866 30866 30867 30861 30866 30866
30874 30865 30868 30870 30870 30868 30868 30867 30867 30866 30870 30866 30862 30868 30867
30866 30870 30868 30870 30867 30866 30867 30867 30867 30866 30866 30858 30862 30865 30868
30874 30866 30866 30866 30870 30869 30868 30866 30866 30865 30866 30865 30861 30868 30873
30868 30867 30868 30868 30867 30866 30868 30867 30866 30866 30866 30866 30864 30864 30869
30874 30867 30868 30870 30866 30869 30868 30867 30867 30866 30866 30866 30862 30864 30867
30874 30871 30868 30870 30866 30866 30873 30866 30865 30866 30866 30866 30862 30865 30873
30874 30867 30866 30870 30870 30867 30867 30867 30867 30866 30866 30866 30868 30868 30866
30876 30871 30866 30870 30870 30866 30873 30867 30867 30866 30870 30866 30861 30865 30866
30865 30866 30866 30867 30867 30866 30868 30867 30865 30866 30866 30866 30866 30865 30868
30875 30866 30866 30868 30870 30866 30868 30868 30867 30866 30866 30867 30865 30874 30868
30864 30868 30866 30871 30870 30866 30868 30867 30867 30866 30866 30867 30859 30865 30868
30865 30868 30866 30869 30867 30866 30873 30867 30868 30866 30866 30866 30863 30865 30865
30867 30870 30865 30869 30866 30866 30873 30867 30865 30865 30866 30865 30861 30868 30874
30867 30868 30868 30869 30866 30866 30868 30865 30867 30867 30865 30865 30865 30871 30874
30869 30871 30868 30867 30866 30869 30867 30867 30865 30866 30866 30866 30863 30874 30873
30873 30867 30866 30870 30870 30866 30867 30867 30867 30866 30870 30866 30861 30865 30868

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 30874 bytes 100%
1,000 30860 bytes -14 bytes 100%
10,000 30859 bytes -1 byte 100%
100,000 30857 bytes -2 bytes 1.16%
1,000,000
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
30962 bytes +105 bytes (+0.34%)
30965 bytes +108 bytes (+0.35%) +3 bytes
30999 bytes +142 bytes (+0.46%) +37 bytes
31009 bytes +152 bytes (+0.49%) +47 bytes
31044 bytes +187 bytes (+0.61%) +82 bytes
31066 bytes +209 bytes (+0.68%) +104 bytes
31076 bytes +219 bytes (+0.71%) +114 bytes
31116 bytes +259 bytes (+0.84%) +154 bytes
31139 bytes +282 bytes (+0.91%) +177 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 24748 bytes -6109 bytes (-19.80%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 25463 bytes -5394 bytes (-17.48%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 27052 bytes -3805 bytes (-12.33%)
Brotli (Wikipedia) brotli brotli -q 11 28406 bytes -2451 bytes (-7.94%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 28527 bytes -2330 bytes (-7.55%)
LZMA2 (Wikipedia) xz xz -9 29564 bytes -1293 bytes (-4.19%)
ZSTD (Wikipedia) zstd zstd -19 30192 bytes -665 bytes (-2.16%)

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