Choose a version:
37% The original file has 51116 bytes (49.9k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 19019 bytes (18.6k, 37%).

After GZIP compression these minified files vary in size:
gzip -6 (default)
  9792 bytes (9.6k)
local copy
gzip -9
  9792 bytes (9.6k)
local copy
libdeflate -12
  9582 bytes (9.4k)
local copy
7zip -mx=9 -tgzip
  9497 bytes (9.3k)
local copy
pigz -11 -n
  9420 bytes (9.2k)
local copy
kzip -s0 -rn -b2
  9402 bytes (9.2k)
local copy
Zopfli
  9392 bytes (9.2k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-1.0.3.pack.js (or via HTTPS)

You will automatically get the smallest jQuery 1.0.3 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

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 --mls64 --bsr15 --lazy --ohh

(found November 23, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 64  --mls64
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

Verify file integrity

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

MD5:
curl --silent --compressed https://code.jquery.com/jquery-1.0.3.pack.js --location | md5sum
337e2c52736ba11a336efe06f38b88cd  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.0.3.pack.zopfli.js.gz | md5sum
337e2c52736ba11a336efe06f38b88cd  -

SHA1:
curl --silent --compressed https://code.jquery.com/jquery-1.0.3.pack.js --location | sha1sum
ddb4126bf4713cb4e0f2310401e58cb9e3f98997  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.0.3.pack.zopfli.js.gz | sha1sum
ddb4126bf4713cb4e0f2310401e58cb9e3f98997  -

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
9392 bytes -1 byte zopfli --i100000 --mls64 --bsr15 --lazy --ohh November 23, 2015 @ 12:06
9393 bytes -2 bytes zopfli --i10000 --mls64 --bsr20 --lazy --ohh November 23, 2015 @ 08:23
9395 bytes -1 byte zopfli --i1000 --mls64 --bsr11 --lazy --ohh September 16, 2015 @ 18:46
9396 bytes -3 bytes zopfli --i1000 --mls64 --bsr12 --lazy --ohh September 16, 2015 @ 18:46
9399 bytes -3 bytes zopfli --i1000 --mls64 --bsr8 --lazy --ohh September 16, 2015 @ 18:46
9402 bytes zopfli --i100 --mls64 --bsr4 --lazy --ohh September 11, 2015 @ 16:39

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 @ 14:38.

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
9394 9394 9394 9409 9398 9406 9397 9408 9418 9420 9422 9418 9422 9423 9436
9419 9416 9419 9404 9405 9393 9395 9435 9424 9417 9426 9429 9451 9431 9449
9402 9400 9404 9404 9407 9397 9398 9406 9393 9405 9404 9408 9417 9413 9413
9410 9404 9406 9401 9393 9392 9401 9408 9406 9412 9395 9402 9418 9414 9414
9406 9406 9406 9408 9410 9398 9397 9408 9393 9413 9406 9405 9414 9412 9412
9403 9403 9404 9401 9404 9392 9401 9406 9407 9406 9401 9406 9414 9411 9411
9401 9402 9404 9401 9408 9393 9394 9401 9406 9406 9406 9402 9418 9416 9416
9404 9404 9407 9405 9405 9392 9401 9406 9393 9404 9403 9404 9416 9417 9417
9404 9403 9403 9405 9405 9393 9402 9404 9405 9406 9401 9410 9416 9412 9412
9403 9403 9404 9401 9404 9392 9392 9399 9405 9410 9401 9402 9414 9413 9414
9404 9403 9404 9404 9404 9399 9392 9404 9404 9400 9404 9406 9418 9416 9416
9405 9404 9404 9404 9405 9392 9392 9403 9404 9412 9404 9402 9414 9413 9416
9406 9404 9405 9402 9405 9393 9403 9401 9405 9406 9402 9401 9417 9416 9416
9402 9401 9405 9401 9405 9393 9401 9403 9407 9395 9406 9406 9414 9416 9416
9405 9402 9404 9401 9406 9393 9401 9405 9406 9412 9396 9411 9414 9414 9414
9401 9401 9404 9405 9405 9393 9401 9405 9406 9406 9404 9407 9418 9417 9415
9405 9404 9405 9402 9404 9392 9401 9400 9401 9410 9404 9406 9416 9417 9417
9401 9404 9404 9400 9404 9393 9393 9404 9405 9412 9406 9405 9418 9415 9415
9401 9404 9404 9401 9405 9392 9399 9399 9392 9400 9404 9414 9413 9412 9412
9404 9404 9404 9400 9405 9399 9392 9406 9405 9412 9404 9404 9417 9414 9414
9404 9402 9404 9400 9404 9399 9392 9405 9405 9412 9404 9415 9418 9406 9406
9404 9401 9403 9404 9404 9392 9392 9404 9392 9401 9401 9414 9411 9419 9419
9403 9404 9404 9401 9405 9393 9395 9406 9406 9412 9403 9405 9418 9413 9413

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 9401 bytes 100%
1,000 9395 bytes -6 bytes 100%
10,000 9393 bytes -2 bytes 100%
100,000 9392 bytes -1 byte 8.70%
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
9402 bytes +10 bytes (+0.11%)
9579 bytes +187 bytes (+1.99%) +177 bytes
9402 bytes +10 bytes (+0.11%)
9411 bytes +19 bytes (+0.20%) +9 bytes
9435 bytes +43 bytes (+0.46%) +33 bytes
9467 bytes +75 bytes (+0.80%) +65 bytes
9502 bytes +110 bytes (+1.17%) +100 bytes
9536 bytes +144 bytes (+1.53%) +134 bytes
9549 bytes +157 bytes (+1.67%) +147 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
Brotli (Wikipedia) brotli brotli -q 11 8737 bytes -655 bytes (-6.97%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 9034 bytes -358 bytes (-3.81%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 9113 bytes -279 bytes (-2.97%)
LZMA2 (Wikipedia) xz xz -9 9264 bytes -128 bytes (-1.36%)
ZPAQ (Wikipedia) zpaq zpaq -method 69 9286 bytes -106 bytes (-1.13%)
Zstandard (Wikipedia) zstd zstd -19 9556 bytes +164 bytes (+1.75%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 9810 bytes +418 bytes (+4.45%)

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