Choose a version:
34% The original file has 247351 bytes (241.6k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 84245 bytes (82.3k, 34%).

After GZIP compression these minified files vary in size:
Microsoft
  37695 bytes (36.8k)
CDN
Boot
  34411 bytes (33.6k)
CDN
jsdelivr
  34411 bytes (33.6k)
CDN
cdnjs
  29769 bytes (29.1k)
CDN
Baidu
  29754 bytes (29.1k)
CDN
unpkg
  29579 bytes (28.9k)
CDN
cdnhttps
  29563 bytes (28.9k)
CDN
gzip -6 (default)
  29558 bytes (28.9k)
local copy
gzip -9
  29502 bytes (28.8k)
local copy
Google
  29497 bytes (28.8k)
CDN
7zip -mx=9 -tgzip
  28559 bytes (27.9k)
local copy
libdeflate -12
  28549 bytes (27.9k)
local copy
Yandex
  28487 bytes (27.8k)
CDN
kzip -s0 -rn -b2
  28483 bytes (27.8k)
local copy
pigz -11 -n
  28477 bytes (27.8k)
local copy
Zopfli
  28464 bytes (27.8k)
local copy
Zopfli (defluff)
  28463 bytes (27.8k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-2.1.1.min.js

You will automatically get the smallest jQuery 2.1.1 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 23 bytes by using my jQuery 2.1.1 Zopfli version instead of the best available CDN (0.08% smaller than Yandex, 28464 vs. 28487 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 --bsr6 --lazy --ohh

(found September 2, 2015)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 2048  --mls2048
block splitting recursion 6  --bsr6
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 (28463 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://code.jquery.com/jquery-2.1.1.min.js --location | md5sum
e40ec2161fe7993196f23c8a07346306  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-2.1.1.min.zopfli.js.gz | md5sum
e40ec2161fe7993196f23c8a07346306  -

SHA1:
curl --silent --compressed http://code.jquery.com/jquery-2.1.1.min.js --location | sha1sum
afb90752e0a90c24b7f724faca86c5f3d15d1178  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-2.1.1.min.zopfli.js.gz | sha1sum
afb90752e0a90c24b7f724faca86c5f3d15d1178  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 37695 bytes e40ec2161fe7993196f23c8a07346306 (invalid)
Google 29497 bytes e40ec2161fe7993196f23c8a07346306 (invalid)
Yandex 28487 bytes e40ec2161fe7993196f23c8a07346306 June 15, 2015 @ 21:17

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Boot 34411 bytes d021c983bd6e7291b43a5cc1fb2ebe99 > //# sourceMappingURL=jquery.min.map
March 18, 2015 @ 09:44
jsdelivr 34411 bytes d021c983bd6e7291b43a5cc1fb2ebe99 > //# sourceMappingURL=jquery.min.map
(invalid)
cdnjs 29769 bytes d021c983bd6e7291b43a5cc1fb2ebe99 > //# sourceMappingURL=jquery.min.map
(invalid)
Baidu 29754 bytes 9a094379d98c6458d480ad5a51c4aa27 only whitespaces differ (invalid)
unpkg 29579 bytes d021c983bd6e7291b43a5cc1fb2ebe99 > //# sourceMappingURL=jquery.min.map
July 11, 2016 @ 15:39
cdnhttps 29563 bytes d021c983bd6e7291b43a5cc1fb2ebe99 only different sourceMappingURL December 24, 2015 @ 07:33

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
28464 bytes -1 byte zopfli --i1000000 --mls2048 --bsr6 --lazy --ohh September 2, 2015 @ 10:59
28465 bytes -1 byte zopfli --i100000 --mls2048 --bsr8 --lazy --ohh September 1, 2015 @ 22:20
28466 bytes -1 byte zopfli --i10000 --mls2048 --bsr14 --lazy --ohh September 1, 2015 @ 20:47
28467 bytes -1 byte zopfli --i1000 --mls2048 --bsr9 --lazy --ohh September 1, 2015 @ 20:32
28468 bytes zopfli --i100 --mls2048 --bsr16 --lazy --ohh September 1, 2015 @ 20:18

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

Most recent activity on July 11, 2016 @ 15:39.

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
28483 28482 28483 28483 28485 28484 28485 28484 28466 28468 28468 28468 28466 28467 28485
28479 28487 28481 28488 28480 28475 28481 28482 28479 28467 28479 28466 28477 28468 28480
28487 28474 28481 28477 28479 28486 28487 28485 28482 28467 28464 28466 28479 28468 28482
28487 28487 28482 28477 28478 28476 28476 28488 28487 28481 28467 28467 28481 28468 28474
28484 28481 28482 28476 28476 28486 28476 28483 28480 28481 28465 28467 28478 28468 28478
28474 28474 28486 28478 28481 28490 28485 28487 28483 28479 28465 28464 28477 28468 28480
28476 28480 28482 28477 28476 28474 28489 28483 28481 28479 28465 28470 28479 28467 28479
28477 28482 28482 28480 28477 28475 28474 28483 28481 28482 28464 28466 28478 28467 28481
28483 28487 28485 28487 28486 28486 28474 28475 28483 28476 28465 28467 28479 28467 28481
28487 28487 28481 28477 28476 28476 28488 28484 28478 28476 28467 28466 28477 28467 28482
28486 28486 28486 28486 28477 28487 28476 28475 28480 28476 28465 28466 28477 28468 28479
28487 28484 28481 28477 28474 28476 28474 28486 28487 28483 28467 28469 28480 28468 28478
28488 28486 28487 28486 28474 28492 28485 28486 28483 28480 28465 28464 28478 28467 28481
28487 28474 28481 28479 28479 28487 28476 28484 28484 28481 28467 28467 28480 28468 28479
28484 28487 28480 28481 28476 28486 28485 28482 28485 28481 28467 28467 28481 28468 28481
28486 28486 28480 28478 28477 28484 28475 28483 28486 28483 28467 28467 28479 28468 28481
28488 28488 28485 28487 28478 28486 28485 28486 28486 28484 28467 28468 28480 28468 28481
28485 28485 28485 28487 28475 28485 28485 28482 28474 28477 28467 28467 28480 28468 28481
28487 28486 28481 28486 28476 28486 28476 28484 28482 28483 28465 28467 28480 28467 28481
28487 28485 28481 28485 28485 28486 28486 28483 28486 28481 28467 28467 28480 28467 28478
28485 28485 28482 28477 28475 28487 28486 28485 28468 28481 28465 28467 28481 28467 28481
28483 28485 28482 28478 28474 28480 28486 28487 28484 28483 28467 28467 28481 28467 28479
28477 28484 28482 28477 28477 28491 28491 28485 28487 28483 28469 28469 28480 28467 28482

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 28468 bytes 100%
1,000 28467 bytes -1 byte 100%
10,000 28466 bytes -1 byte 100%
100,000 28464 bytes -2 bytes 16.52%
1,000,000 28464 bytes 0.29%
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
28560 bytes +96 bytes (+0.34%) +77 bytes
28560 bytes +96 bytes (+0.34%) +77 bytes
28483 bytes +19 bytes (+0.07%)
28493 bytes +29 bytes (+0.10%) +10 bytes
28493 bytes +29 bytes (+0.10%) +10 bytes
28521 bytes +57 bytes (+0.20%) +38 bytes
28561 bytes +97 bytes (+0.34%) +78 bytes
28599 bytes +135 bytes (+0.47%) +116 bytes
28629 bytes +165 bytes (+0.58%) +146 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 23640 bytes -4824 bytes (-16.95%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 24105 bytes -4359 bytes (-15.31%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 25418 bytes -3046 bytes (-10.70%)
Brotli (Wikipedia) brotli brotli -q 11 26613 bytes -1851 bytes (-6.50%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 26927 bytes -1537 bytes (-5.40%)
LZMA2 (Wikipedia) xz xz -9 27692 bytes -772 bytes (-2.71%)
ZSTD (Wikipedia) zstd zstd -19 28204 bytes -260 bytes (-0.91%)

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