Choose a version:
33% The original file has 294199 bytes (287.3k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 97403 bytes (95.1k, 33%).

After GZIP compression these minified files vary in size:
Microsoft
  43458 bytes (42.4k)
CDN
Boot
  39559 bytes (38.6k)
CDN
cdnhttps
  38154 bytes (37.3k)
CDN
cdnjs
  34093 bytes (33.3k)
CDN
gzip -6 (default)
  33915 bytes (33.1k)
local copy
unpkg
  33890 bytes (33.1k)
CDN
Google
  33862 bytes (33.1k)
CDN
gzip -9
  33859 bytes (33.1k)
local copy
jsdelivr
  33858 bytes (33.1k)
CDN
7zip -mx=9 -tgzip
  32737 bytes (32.0k)
local copy
libdeflate -12
  32724 bytes (32.0k)
local copy
Yandex
  32670 bytes (31.9k)
CDN
kzip -s0 -rn -b4
  32668 bytes (31.9k)
local copy
pigz -11 -n
  32663 bytes (31.9k)
local copy
Zopfli
  32639 bytes (31.9k)
local copy
Zopfli (defluff)
  32638 bytes (31.9k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-1.12.1.min.js (or via HTTPS)

You will automatically get the smallest jQuery 1.12.1 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 31 bytes by using my jQuery 1.12.1 Zopfli version instead of the best available CDN (0.09% smaller than Yandex, 32639 vs. 32670 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 --mls2048 --bsr15 --lazy --ohh

(found February 24, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 2048  --mls2048
block splitting recursion 15  --bsr15
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

Even Smaller Files Thanks To Defluff

Zopfli's output can be further optimized by the defluff tool.
In this particular case, defluff saves 1 more byte (32638 bytes).

Verify file integrity

After decompression, my uncompressed files are identical to the original ones:

MD5:
curl --silent --compressed https://code.jquery.com/jquery-1.12.1.min.js --location | md5sum
1d244cb043be8157f0050ce9e45c9ef2  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.12.1.min.zopfli.js.gz | md5sum
1d244cb043be8157f0050ce9e45c9ef2  -

SHA1:
curl --silent --compressed https://code.jquery.com/jquery-1.12.1.min.js --location | sha1sum
f16bd01623fd56d1372ea2eb55cd52a28cd883f8  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.12.1.min.zopfli.js.gz | sha1sum
f16bd01623fd56d1372ea2eb55cd52a28cd883f8  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 43458 bytes 1d244cb043be8157f0050ce9e45c9ef2 March 14, 2016 @ 19:20
Boot 39559 bytes 1d244cb043be8157f0050ce9e45c9ef2 February 23, 2016 @ 15:02
cdnhttps 38154 bytes 1d244cb043be8157f0050ce9e45c9ef2 November 22, 2016 @ 16:35
cdnjs 34093 bytes 1d244cb043be8157f0050ce9e45c9ef2 February 23, 2016 @ 06:47
unpkg 33890 bytes 1d244cb043be8157f0050ce9e45c9ef2 July 11, 2016 @ 15:39
Google 33862 bytes 1d244cb043be8157f0050ce9e45c9ef2 March 18, 2016 @ 22:26
jsdelivr 33858 bytes 1d244cb043be8157f0050ce9e45c9ef2 February 22, 2016 @ 21:01
Yandex 32670 bytes 1d244cb043be8157f0050ce9e45c9ef2 (invalid)

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
32639 bytes -2 bytes zopfli --i1000000 --mls2048 --bsr15 --lazy --ohh February 24, 2016 @ 15:24
32641 bytes -3 bytes zopfli --i100000 --mls2048 --bsr15 --lazy --ohh February 23, 2016 @ 19:21
32644 bytes -2 bytes zopfli --i100000 --mls16384 --bsr25 --lazy --ohh February 23, 2016 @ 12:34
32646 bytes -2 bytes zopfli --i10000 --mls16384 --bsr25 --lazy --ohh February 23, 2016 @ 11:21
32648 bytes -1 byte zopfli --i1000 --mls2048 --bsr15 --lazy --ohh February 23, 2016 @ 11:15
32649 bytes zopfli --i100 --mls2048 --bsr15 --lazy --ohh February 23, 2016 @ 10:58

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
32654 32654 32654 32654 32652 32652 32652 32654 32654 32655 32656 32656 32661 32657 32657
32650 32649 32649 32648 32651 32651 32650 32650 32645 32649 32650 32650 32657 32647 32647
32653 32652 32653 32651 32652 32653 32654 32655 32656 32653 32646 32649 32646 32649 32647
32652 32646 32652 32645 32652 32647 32651 32652 32652 32653 32640 32649 32646 32649 32645
32646 32645 32654 32654 32653 32652 32652 32654 32654 32655 32656 32648 32650 32649 32651
32646 32647 32645 32646 32652 32653 32653 32652 32654 32654 32648 32646 32650 32645 32650
32650 32646 32647 32648 32652 32651 32652 32652 32653 32652 32647 32647 32646 32645 32649
32646 32645 32652 32658 32652 32646 32652 32654 32653 32651 32647 32647 32647 32649 32647
32653 32652 32652 32645 32652 32652 32652 32654 32654 32652 32646 32649 32646 32648 32649
32648 32645 32647 32646 32652 32652 32652 32651 32653 32652 32646 32649 32648 32645 32647
32650 32645 32652 32651 32652 32652 32652 32652 32654 32651 32649 32647 32652 32649 32646
32646 32645 32648 32645 32648 32653 32652 32651 32654 32651 32639 32649 32650 32645 32642
32646 32646 32647 32647 32648 32648 32652 32652 32654 32651 32647 32647 32646 32646 32650
32646 32647 32647 32646 32652 32647 32652 32651 32654 32651 32647 32647 32649 32645 32651
32646 32645 32647 32645 32652 32646 32652 32651 32652 32651 32648 32645 32646 32645 32647
32649 32648 32646 32646 32652 32652 32652 32651 32652 32651 32647 32647 32646 32645 32647
32653 32647 32646 32644 32653 32652 32651 32651 32653 32652 32646 32647 32647 32647 32647
32654 32652 32652 32648 32651 32648 32653 32652 32653 32651 32647 32647 32649 32645 32645
32647 32647 32646 32645 32649 32646 32653 32651 32652 32652 32648 32647 32648 32648 32645
32647 32645 32647 32644 32651 32648 32652 32653 32645 32651 32648 32649 32644 32646 32645
32653 32652 32652 32645 32651 32653 32651 32651 32653 32652 32647 32649 32650 32644 32648
32654 32652 32652 32646 32651 32652 32651 32651 32653 32652 32653 32649 32650 32645 32647
32646 32645 32645 32646 32648 32647 32652 32654 32653 32651 32652 32647 32648 32645 32647

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 32649 bytes 100%
1,000 32645 bytes -4 bytes 100%
10,000 32644 bytes -1 byte 100%
100,000 32641 bytes -3 bytes 2.90%
1,000,000 32639 bytes -2 bytes 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
32748 bytes +109 bytes (+0.33%) +80 bytes
32747 bytes +108 bytes (+0.33%) +79 bytes
32676 bytes +37 bytes (+0.11%) +8 bytes
32683 bytes +44 bytes (+0.13%) +15 bytes
32668 bytes +29 bytes (+0.09%)
32703 bytes +64 bytes (+0.20%) +35 bytes
32748 bytes +109 bytes (+0.33%) +80 bytes
32775 bytes +136 bytes (+0.42%) +107 bytes
32805 bytes +166 bytes (+0.51%) +137 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 26706 bytes -5933 bytes (-18.18%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 27463 bytes -5176 bytes (-15.86%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 29157 bytes -3482 bytes (-10.67%)
Brotli (Wikipedia) brotli brotli -q 11 30431 bytes -2208 bytes (-6.76%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 30694 bytes -1945 bytes (-5.96%)
LZMA2 (Wikipedia) xz xz -9 31572 bytes -1067 bytes (-3.27%)
Zstandard (Wikipedia) zstd zstd -19 32184 bytes -455 bytes (-1.39%)

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