Choose a version:
34% The original file has 244963 bytes (239.2k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 83615 bytes (81.7k, 34%).

After GZIP compression these minified files vary in size:
Microsoft
  37460 bytes (36.6k)
CDN, direct link
Boot
  34151 bytes (33.4k)
CDN, direct link
jsdelivr
  34151 bytes (33.4k)
CDN, direct link
cdnjs
  29559 bytes (28.9k)
CDN, direct link
unpkg
  29374 bytes (28.7k)
CDN, direct link
gzip -6 (default)
  29364 bytes (28.7k)
local copy
cdnhttps
  29344 bytes (28.7k)
CDN, direct link
gzip -9
  29308 bytes (28.6k)
local copy
Google
  29301 bytes (28.6k)
CDN, direct link
7zip -mx=9 -tgzip
  28376 bytes (27.7k)
local copy
libdeflate -12
  28348 bytes (27.7k)
local copy
Yandex
  28307 bytes (27.6k)
CDN, direct link
pigz -11 -n
  28289 bytes (27.6k)
local copy
kzip -s0 -rn -b2
  28288 bytes (27.6k)
local copy
Zopfli
  28277 bytes (27.6k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-2.1.0.min.js

You will automatically get the smallest jQuery 2.1.0 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 30 bytes by using my jQuery 2.1.0 Zopfli version instead of the best available CDN (0.11% smaller than Yandex, 28277 vs. 28307 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 --mls1024 --bsr8 --lazy --ohh

(found September 1, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 1024  --mls1024
block splitting recursion 8  --bsr8
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-2.1.0.min.js --location | md5sum
5ca7582261c421482436dfdf3af9bffe  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-2.1.0.min.zopfli.js.gz | md5sum
5ca7582261c421482436dfdf3af9bffe  -

SHA1:
curl --silent --compressed http://code.jquery.com/jquery-2.1.0.min.js --location | sha1sum
98884258cbdb0d939fa2c5e74fc7ac9e56d8170f  -
curl --silent --compressed http://minime.stephan-brumme.com/files/jquery/jquery-2.1.0.min.zopfli.js.gz | sha1sum
98884258cbdb0d939fa2c5e74fc7ac9e56d8170f  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Microsoft 37460 bytes 5ca7582261c421482436dfdf3af9bffe (invalid)
Boot 34151 bytes 5ca7582261c421482436dfdf3af9bffe March 18, 2015 @ 09:43
jsdelivr 34151 bytes 5ca7582261c421482436dfdf3af9bffe (invalid)
cdnjs 29559 bytes 5ca7582261c421482436dfdf3af9bffe (invalid)
cdnhttps 29344 bytes 5ca7582261c421482436dfdf3af9bffe December 24, 2015 @ 07:33
Google 29301 bytes 5ca7582261c421482436dfdf3af9bffe (invalid)
Yandex 28307 bytes 5ca7582261c421482436dfdf3af9bffe June 15, 2015 @ 21:17

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
unpkg 29374 bytes 1fe1caacda14275805e4c6fb15f2503b > //# sourceMappingURL=jquery.min.map
July 11, 2016 @ 15:39

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
28277 bytes -4 bytes zopfli --i100000 --mls1024 --bsr8 --lazy --ohh September 1, 2015 @ 22:48
28281 bytes -1 byte zopfli --i10000 --mls512 --bsr6 --lazy --ohh September 1, 2015 @ 21:13
28282 bytes -1 byte zopfli --i10000 --mls1024 --bsr8 --lazy --ohh September 1, 2015 @ 20:50
28283 bytes -1 byte zopfli --i1000 --mls512 --bsr6 --lazy --ohh September 1, 2015 @ 20:33
28284 bytes zopfli --i100 --mls1024 --bsr12 --lazy --ohh September 1, 2015 @ 20:24

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 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
28288 28290 28288 28292 28287 28295 28293 28295 28278 28278 28283 28282 28278 28288 28281
28282 28290 28290 28290 28290 28285 28286 28286 28289 28284 28287 28279 28282 28281 28289
28294 28293 28291 28286 28287 28306 28284 28286 28277 28278 28285 28278 28280 28288 28291
28288 28283 28282 28303 28286 28304 28286 28286 28287 28285 28287 28282 28290 28283 28291
28286 28314 28295 28283 28286 28305 28286 28294 28293 28277 28285 28279 28288 28283 28292
28287 28290 28289 28293 28293 28306 28286 28286 28290 28277 28287 28283 28278 28280 28291
28310 28297 28296 28294 28297 28306 28285 28287 28284 28284 28287 28279 28288 28279 28290
28289 28300 28311 28293 28283 28306 28286 28287 28284 28287 28285 28278 28279 28281 28289
28294 28293 28293 28294 28296 28306 28287 28286 28284 28277 28287 28279 28279 28283 28291
28285 28291 28294 28286 28282 28286 28286 28286 28284 28283 28285 28280 28279 28283 28293
28314 28296 28295 28282 28286 28305 28286 28284 28284 28284 28284 28277 28279 28280 28291
28294 28286 28293 28286 28282 28306 28286 28287 28295 28286 28288 28282 28280 28282 28291
28286 28311 28295 28289 28284 28306 28286 28286 28284 28284 28285 28278 28278 28283 28291
28286 28286 28311 28307 28282 28294 28286 28286 28286 28285 28287 28282 28280 28283 28291
28286 28311 28310 28308 28286 28295 28286 28286 28286 28286 28287 28282 28280 28280 28293
28304 28302 28299 28292 28282 28307 28288 28286 28287 28285 28289 28282 28289 28281 28290
28287 28295 28293 28291 28296 28307 28286 28286 28286 28286 28289 28282 28280 28280 28290
28293 28296 28297 28304 28282 28305 28286 28286 28286 28286 28287 28282 28282 28282 28291
28286 28292 28286 28294 28304 28306 28286 28286 28295 28286 28287 28282 28281 28283 28290
28286 28300 28294 28283 28282 28306 28287 28289 28295 28284 28288 28282 28281 28280 28291
28286 28292 28301 28295 28305 28295 28286 28286 28286 28285 28287 28282 28281 28282 28291
28286 28294 28295 28307 28283 28294 28285 28286 28287 28280 28288 28282 28280 28283 28292
28286 28294 28294 28305 28284 28305 28286 28286 28286 28285 28287 28282 28280 28284 28291

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 28284 bytes 100%
1,000 28283 bytes -1 byte 100%
10,000 28278 bytes -5 bytes 100%
100,000 28277 bytes -1 byte 15.94%
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
28369 bytes +92 bytes (+0.33%) +81 bytes
28370 bytes +93 bytes (+0.33%) +82 bytes
28288 bytes +11 bytes (+0.04%)
28299 bytes +22 bytes (+0.08%) +11 bytes
28307 bytes +30 bytes (+0.11%) +19 bytes
28349 bytes +72 bytes (+0.25%) +61 bytes
28388 bytes +111 bytes (+0.39%) +100 bytes
28417 bytes +140 bytes (+0.50%) +129 bytes
28449 bytes +172 bytes (+0.61%) +161 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 23424 bytes -4853 bytes (-17.16%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 23933 bytes -4344 bytes (-15.36%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 25208 bytes -3069 bytes (-10.85%)
Brotli (Wikipedia) brotli brotli -q 11 26479 bytes -1798 bytes (-6.36%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 26712 bytes -1565 bytes (-5.53%)
LZMA2 (Wikipedia) xz xz -9 27524 bytes -753 bytes (-2.66%)
ZSTD (Wikipedia) zstd zstd -19 28036 bytes -241 bytes (-0.85%)

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