Choose a version:
39% The original file has 234995 bytes (229.5k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 91342 bytes (89.2k, 39%).

After GZIP compression these minified files vary in size:
Microsoft
  40713 bytes (39.8k)
CDN
Boot
  37016 bytes (36.1k)
CDN
Baidu
  32244 bytes (31.5k)
CDN
cdnjs
  32235 bytes (31.5k)
CDN
gzip -6 (default)
  32008 bytes (31.3k)
local copy
Google
  31988 bytes (31.2k)
CDN
cdnhttps
  31988 bytes (31.2k)
CDN
gzip -9
  31948 bytes (31.2k)
local copy
libdeflate -12
  30891 bytes (30.2k)
local copy
kzip -s0 -rn -b0
  30886 bytes (30.2k)
local copy
7zip -mx=9 -tgzip
  30869 bytes (30.1k)
local copy
Yandex
  30813 bytes (30.1k)
CDN
pigz -11 -n
  30803 bytes (30.1k)
local copy
Zopfli
  30770 bytes (30.0k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-1.6.1.min.js

You will automatically get the smallest jQuery 1.6.1 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 43 bytes by using my jQuery 1.6.1 Zopfli version instead of the best available CDN (0.14% smaller than Yandex, 30770 vs. 30813 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 --mls8192 --bsr40 --lazy --ohh

(found January 8, 2016)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 8192  --mls8192
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-1.6.1.min.js --location | md5sum
a34f78c3aecd182144818eb4b7303fda  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-1.6.1.min.zopfli.js.gz | md5sum
a34f78c3aecd182144818eb4b7303fda  -

SHA1:
curl --silent --compressed http://code.jquery.com/jquery-1.6.1.min.js --location | sha1sum
6fca78dac2797c02d86a4bf6514eda398b7dbe62  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-1.6.1.min.zopfli.js.gz | sha1sum
6fca78dac2797c02d86a4bf6514eda398b7dbe62  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 40713 bytes a34f78c3aecd182144818eb4b7303fda (invalid)
Boot 37016 bytes a34f78c3aecd182144818eb4b7303fda March 18, 2015 @ 09:42
cdnjs 32235 bytes a34f78c3aecd182144818eb4b7303fda (invalid)
Google 31988 bytes a34f78c3aecd182144818eb4b7303fda (invalid)
cdnhttps 31988 bytes a34f78c3aecd182144818eb4b7303fda December 24, 2015 @ 07:33
Yandex 30813 bytes a34f78c3aecd182144818eb4b7303fda June 15, 2015 @ 21:17

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Baidu 32244 bytes 3f34e6e22254e5552986586ba5d7d848 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
30770 bytes -1 byte zopfli --i100000 --mls8192 --bsr40 --lazy --ohh January 8, 2016 @ 09:49
30771 bytes -1 byte zopfli --i100000 --mls8192 --bsr21 --lazy --ohh November 23, 2015 @ 11:32
30772 bytes -2 bytes zopfli --i100000 --mls8192 --bsr11 --lazy --ohh September 2, 2015 @ 01:19
30774 bytes -5 bytes zopfli --i10000 --mls8192 --bsr11 --lazy --ohh September 1, 2015 @ 21:17
30779 bytes -9 bytes zopfli --i1000 --mls8192 --bsr11 --lazy --ohh September 1, 2015 @ 20:37
30788 bytes zopfli --i100 --mls8192 --bsr11 --lazy --ohh September 1, 2015 @ 20:27

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

Most recent activity on June 16, 2016 @ 14:37.

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
30800 30788 30795 30787 30789 30783 30787 30782 30782 30777 30782 30777 30778 30781 30788
30781 30780 30782 30782 30784 30779 30786 30783 30782 30785 30779 30780 30782 30785 30781
30781 30779 30780 30781 30779 30782 30782 30788 30781 30783 30781 30782 30782 30777 30792
30780 30780 30780 30780 30783 30780 30779 30778 30784 30781 30783 30779 30779 30777 30774
30781 30779 30781 30782 30781 30781 30782 30784 30781 30784 30782 30781 30781 30774 30781
30781 30780 30780 30781 30779 30782 30786 30781 30784 30785 30781 30778 30774 30778 30780
30780 30779 30780 30780 30781 30781 30782 30778 30781 30782 30781 30779 30778 30775 30781
30781 30780 30781 30781 30781 30782 30782 30780 30781 30783 30781 30778 30772 30776 30793
30780 30780 30781 30781 30785 30779 30782 30783 30782 30781 30780 30780 30777 30775 30779
30779 30780 30779 30779 30778 30778 30781 30780 30781 30782 30781 30781 30780 30777 30780
30781 30781 30780 30780 30781 30780 30783 30778 30784 30781 30781 30779 30771 30782 30778
30780 30780 30782 30780 30780 30789 30784 30779 30779 30781 30781 30779 30776 30778 30791
30783 30780 30782 30780 30779 30780 30779 30786 30778 30781 30781 30778 30776 30782 30790
30782 30782 30780 30780 30781 30781 30781 30780 30781 30782 30781 30779 30776 30776 30790
30785 30784 30780 30783 30781 30791 30781 30779 30777 30785 30781 30779 30774 30781 30791
30781 30780 30780 30781 30780 30781 30782 30788 30782 30783 30781 30779 30774 30783 30791
30780 30780 30782 30783 30783 30781 30781 30782 30778 30783 30781 30779 30777 30778 30780
30780 30780 30781 30781 30782 30779 30782 30779 30778 30783 30781 30779 30771 30778 30790
30784 30782 30784 30781 30781 30778 30782 30783 30777 30782 30781 30778 30774 30781 30780
30779 30780 30780 30782 30781 30781 30781 30779 30781 30782 30781 30777 30774 30777 30780
30781 30779 30781 30781 30780 30779 30781 30788 30781 30782 30781 30779 30780 30776 30780
30782 30780 30782 30780 30779 30782 30779 30778 30778 30781 30780 30779 30776 30778 30790
30781 30779 30779 30780 30779 30781 30781 30778 30779 30783 30776 30780 30770 30782 30779

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 30782 bytes 100%
1,000 30776 bytes -6 bytes 100%
10,000 30772 bytes -4 bytes 100%
100,000 30770 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
30886 bytes +116 bytes (+0.38%)
30886 bytes +116 bytes (+0.38%)
30923 bytes +153 bytes (+0.50%) +37 bytes
30913 bytes +143 bytes (+0.46%) +27 bytes
30927 bytes +157 bytes (+0.51%) +41 bytes
30963 bytes +193 bytes (+0.63%) +77 bytes
30983 bytes +213 bytes (+0.69%) +97 bytes
30999 bytes +229 bytes (+0.74%) +113 bytes
31034 bytes +264 bytes (+0.86%) +148 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 24764 bytes -6006 bytes (-19.52%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 25460 bytes -5310 bytes (-17.26%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 26964 bytes -3806 bytes (-12.37%)
Brotli (Wikipedia) brotli brotli -q 11 28277 bytes -2493 bytes (-8.10%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 28515 bytes -2255 bytes (-7.33%)
LZMA2 (Wikipedia) xz xz -9 29492 bytes -1278 bytes (-4.15%)
ZSTD (Wikipedia) zstd zstd -19 30156 bytes -614 bytes (-2.00%)

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