Choose a version:
56% The original file has 97623 bytes (95.3k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 54620 bytes (53.3k, 56%).

After GZIP compression these minified files vary in size:
gzip -6 (default)
  16097 bytes (15.7k)
 local copy
gzip -9
  16054 bytes (15.7k)
 local copy
libdeflate -12
  15507 bytes (15.1k)
 local copy
kzip -s0 -rn -b0
  15480 bytes (15.1k)
 local copy
7zip -mx=9 -tgzip
  15468 bytes (15.1k)
 local copy
zultra
  15468 bytes (15.1k)
 local copy
pigz -11 -n
  15436 bytes (15.1k)
 local copy
Zopfli
  15421 bytes (15.1k)
 local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-1.2.4.min.js (or via HTTPS)

You will automatically get the smallest jQuery 1.2.4 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 --mls16 --bsr22 --lazy --ohh

(found January 7, 2016)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 16  --mls16
block splitting recursion 22  --bsr22
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-1.2.4.min.js --location | md5sum
5acd330e6410301e021ad128bd34578d  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.2.4.min.zopfli.js.gz | md5sum
5acd330e6410301e021ad128bd34578d  -

SHA1:
curl --silent --compressed https://code.jquery.com/jquery-1.2.4.min.js --location | sha1sum
0d2bc9db63acd9cc238a4925e79f9a3079490970  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-1.2.4.min.zopfli.js.gz | sha1sum
0d2bc9db63acd9cc238a4925e79f9a3079490970  -

Other Versions

Available jQuery versions at minime.stephan-brumme.com:

3.6.1, 3.6.0,
3.5.1, 3.5.0,
3.4.1, 3.4.0,
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
15421 bytes -1 byte zopfli --i100000 --mls16 --bsr22 --lazy --ohh January 7, 2016 @ 11:59
15422 bytes -2 bytes zopfli --i100000 --mls512 --bsr4 --lazy --ohh September 2, 2015 @ 02:25
15424 bytes -1 byte zopfli --i1000 --mls512 --bsr4 --lazy --ohh September 1, 2015 @ 20:41
15425 bytes – zopfli --i100 --mls512 --bsr4 --lazy --ohh September 1, 2015 @ 20:29

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

Most recent activity on July 20, 2020 @ 12:52.

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
2 15444 15444 15445 15429 15439 15439 15440 15441 15442 15435 15433 15429 15443 15445 15435
4 15447 15446 15446 15428 15428 15429 15427 15429 15422 15428 15427 15428 15429 15430 15429
6 15441 15441 15431 15429 15430 15429 15426 15434 15429 15434 15428 15428 15428 15434 15429
7 15443 15441 15444 15426 15426 15443 15426 15427 15428 15427 15427 15426 15428 15444 15428
8 15442 15441 15430 15428 15428 15431 15427 15428 15429 15428 15430 15428 15428 15435 15427
9 15443 15444 15426 15426 15429 15428 15427 15427 15427 15430 15428 15430 15430 15428 15431
10 15427 15428 15442 15427 15428 15431 15427 15427 15425 15428 15432 15443 15447 15441 15428
11 15443 15444 15443 15428 15429 15428 15426 15430 15430 15428 15431 15431 15442 15429 15429
12 15427 15427 15426 15429 15427 15428 15429 15431 15428 15427 15430 15431 15427 15427 15427
13 15442 15442 15442 15444 15427 15443 15427 15429 15427 15433 15427 15428 15427 15434 15430
14 15442 15442 15443 15443 15428 15427 15426 15427 15431 15429 15431 15428 15428 15441 15427
15 15442 15442 15427 15426 15427 15427 15426 15427 15428 15427 15427 15427 15424 15428 15422
16 15444 15442 15444 15427 15427 15429 15426 15427 15430 15428 15430 15429 15428 15443 15428
17 15441 15442 15441 15444 15431 15431 15427 15430 15430 15430 15430 15430 15428 15442 15430
18 15443 15445 15444 15444 15445 15427 15426 15427 15428 15427 15427 15426 15428 15442 15429
19 15442 15441 15426 15427 15427 15431 15426 15428 15428 15432 15424 15427 15427 15429 15429
20 15442 15442 15445 15426 15429 15427 15427 15429 15428 15428 15425 15427 15427 15429 15428
21 15430 15432 15444 15428 15428 15427 15427 15429 15429 15427 15425 15427 15427 15442 15429
22 15441 15441 15443 15421 15427 15431 15427 15429 15429 15429 15426 15426 15428 15430 15429
23 15444 15444 15444 15444 15427 15427 15428 15428 15429 15429 15423 15427 15428 15428 15428
25 15426 15426 15428 15427 15428 15426 15426 15429 15428 15429 15430 15429 15428 15429 15429
30 15443 15441 15442 15426 15427 15430 15427 15429 15429 15427 15429 15426 15427 15428 15429
40 15441 15442 15441 15444 15428 15428 15426 15429 15428 15429 15427 15426 15428 15430 15430

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 15424 bytes – 100%
1,000 15424 bytes – 100%
10,000 15423 bytes -1 byte 100%
100,000 15421 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
(any) 15480 bytes +59 bytes (+0.38%) –
1 15481 bytes +60 bytes (+0.39%) +1 byte
2 15496 bytes +75 bytes (+0.49%) +16 bytes
3 15513 bytes +92 bytes (+0.60%) +33 bytes
4 15549 bytes +128 bytes (+0.83%) +69 bytes
5 15544 bytes +123 bytes (+0.80%) +64 bytes
6 15587 bytes +166 bytes (+1.08%) +107 bytes
7 15612 bytes +191 bytes (+1.24%) +132 bytes
8 15629 bytes +208 bytes (+1.35%) +149 bytes

Non-DEFLATE Algorithms

Archivers based on completely different compression algorithms often produce superior results.
Unfortunately, browsers only support gzip compression at the moment.
However, support for Brotli is constantly growing - for example, your browser actually supports it !
Algorithm Program Parameters Size Compared To Best Zopfli
ZPAQ (Wikipedia) zpaq zpaq -method 69 13059 bytes -2362 bytes (-15.32%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 13255 bytes -2166 bytes (-14.05%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 14404 bytes -1017 bytes (-6.59%)
Brotli (Wikipedia) brotli brotli -q 11 14506 bytes -915 bytes (-5.93%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 15043 bytes -378 bytes (-2.45%)
LZMA2 (Wikipedia) xz xz -9 15244 bytes -177 bytes (-1.15%)
Zstandard (Wikipedia) zstd zstd -19 15384 bytes -37 bytes (-0.24%)

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):
Load and Parse Data


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 2026.
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

All trademarks are property of their respective owners. You know, the boring legal stuff.