Choose a version:
31% The original file has 287630 bytes (280.9k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 89476 bytes (87.4k, 31%).

After GZIP compression these minified files vary in size:
unpkg
  36300 bytes (35.4k)
 CDN
cdnjs
  31147 bytes (30.4k)
 CDN
Google
  31021 bytes (30.3k)
 CDN
Microsoft
  30976 bytes (30.3k)
 CDN
gzip -6 (default)
  30970 bytes (30.2k)
 local copy
Boot
  30941 bytes (30.2k)
 CDN
gzip -9
  30899 bytes (30.2k)
 local copy
libdeflate -12
  29950 bytes (29.2k)
 local copy
7zip -mx=9 -tgzip
  29948 bytes (29.2k)
 local copy
zultra
  29869 bytes (29.2k)
 local copy
kzip -s0 -rn -b2
  29840 bytes (29.1k)
 local copy
pigz -11 -n
  29838 bytes (29.1k)
 local copy
Zopfli
  29828 bytes (29.1k)
 local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/jquery/jquery-3.5.1.min.js (or via HTTPS)

You will automatically get the smallest jQuery 3.5.1 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 1113 bytes by using my jQuery 3.5.1 Zopfli version instead of the best available CDN (3.73% smaller than Boot, 29828 vs. 30941 bytes):
Download
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 --i10000 --mb8 --mls2048 --bsr16 --lazy --ohh

(found May 5, 2020)
Description Value Parameter
iterations 10000  --i10000
maximum blocks 8  --mb8
maximum length score 2048  --mls2048
block splitting recursion 16  --bsr16
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-3.5.1.min.js --location | md5sum
dc5e7f18c8d36ac1d3d4753a87c98d0a  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-3.5.1.min.zopfli.js.gz | md5sum
dc5e7f18c8d36ac1d3d4753a87c98d0a  -

SHA1:
curl --silent --compressed https://code.jquery.com/jquery-3.5.1.min.js --location | sha1sum
c8e1c8b386dc5b7a9184c763c88d19a346eb3342  -
curl --silent --compressed https://minime.stephan-brumme.com/files/jquery/jquery-3.5.1.min.zopfli.js.gz | sha1sum
c8e1c8b386dc5b7a9184c763c88d19a346eb3342  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
unpkg 36300 bytes dc5e7f18c8d36ac1d3d4753a87c98d0a (invalid)
cdnjs 31147 bytes dc5e7f18c8d36ac1d3d4753a87c98d0a May 5, 2020 @ 01:16
Google 31021 bytes dc5e7f18c8d36ac1d3d4753a87c98d0a May 8, 2020 @ 09:05
Microsoft 30976 bytes dc5e7f18c8d36ac1d3d4753a87c98d0a August 11, 2020 @ 18:38
Boot 30941 bytes dc5e7f18c8d36ac1d3d4753a87c98d0a May 5, 2020 @ 01:16

Note: only the MD5 hashes are shown to keep things simple.

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
29828 bytes -1 byte zopfli --i10000 --mls2048 --bsr16 --lazy --ohh May 5, 2020 @ 15:26
29829 bytes -1 byte zopfli --i10000 --mls2048 --bsr8 --lazy --ohh May 5, 2020 @ 14:58
29830 bytes -2 bytes zopfli --i1000 --mls2048 --bsr14 --lazy --ohh May 5, 2020 @ 13:24
29832 bytes -1 byte zopfli --i1000 --mls128 --bsr9 --lazy --ohh May 5, 2020 @ 13:23
29833 bytes – zopfli --i100 --mls2048 --bsr14 --lazy --ohh May 5, 2020 @ 12:58

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

Most recent activity on August 11, 2020 @ 18:38.

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, 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
2 29833 29834 29834 29835 29834 29829 29834 29833 29834 29835 29838 29831 29837 29831 29855
4 29832 29832 29858 29876 29860 29831 29829 29829 29831 29832 29832 29834 29831 29831 29857
6 29837 29857 29856 29837 29834 29839 29842 29842 29839 29832 29831 29832 29844 29843 29832
7 29838 29839 29840 29842 29843 29843 29843 29843 29832 29831 29843 29832 29831 29835 29854
8 29842 29840 29843 29838 29840 29836 29833 29833 29834 29835 29829 29838 29831 29837 29854
9 29857 29857 29859 29871 29860 29857 29829 29831 29832 29832 29831 29836 29831 29837 29855
10 29835 29835 29859 29838 29839 29836 29832 29835 29832 29831 29831 29832 29831 29836 29855
11 29836 29840 29839 29837 29840 29839 29829 29835 29832 29832 29831 29833 29831 29839 29854
12 29858 29858 29860 29860 29854 29837 29834 29835 29838 29831 29832 29832 29831 29837 29854
13 29839 29859 29860 29838 29839 29840 29832 29835 29832 29831 29836 29831 29834 29840 29853
14 29840 29839 29839 29837 29840 29857 29832 29835 29832 29832 29829 29831 29832 29842 29855
15 29839 29837 29839 29836 29839 29840 29831 29840 29832 29831 29831 29831 29831 29837 29854
16 29837 29840 29839 29837 29837 29839 29831 29832 29853 29838 29828 29831 29831 29841 29853
17 29840 29839 29839 29837 29838 29857 29831 29835 29832 29832 29831 29832 29831 29840 29853
18 29838 29838 29839 29837 29836 29835 29831 29835 29832 29838 29831 29832 29831 29837 29853
19 29856 29859 29857 29837 29836 29836 29831 29835 29832 29832 29842 29832 29835 29840 29854
20 29859 29859 29859 29837 29852 29857 29830 29834 29831 29836 29836 29829 29834 29841 29853
21 29841 29839 29839 29840 29840 29837 29832 29835 29832 29832 29832 29831 29831 29840 29853
22 29836 29837 29834 29836 29840 29836 29831 29835 29832 29832 29832 29832 29834 29840 29854
23 29840 29839 29838 29839 29840 29839 29831 29835 29832 29832 29842 29832 29835 29840 29853
25 29840 29839 29839 29838 29839 29831 29829 29835 29832 29832 29832 29831 29832 29837 29854
30 29837 29839 29839 29837 29839 29831 29829 29836 29832 29831 29831 29831 29834 29840 29852
40 29860 29859 29858 29838 29840 29837 29833 29832 29832 29832 29831 29832 29831 29839 29853

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 29833 bytes – 100%
1,000 29830 bytes -3 bytes 100%
10,000 29828 bytes -2 bytes 100%
100,000 29828 bytes – 3.48%
1,000,000 29828 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
(any) 29923 bytes +95 bytes (+0.32%) +83 bytes
1 29923 bytes +95 bytes (+0.32%) +83 bytes
2 29840 bytes +12 bytes (+0.04%) –
3 29856 bytes +28 bytes (+0.09%) +16 bytes
4 29876 bytes +48 bytes (+0.16%) +36 bytes
5 29903 bytes +75 bytes (+0.25%) +63 bytes
6 29937 bytes +109 bytes (+0.37%) +97 bytes
7 29981 bytes +153 bytes (+0.51%) +141 bytes
8 30022 bytes +194 bytes (+0.65%) +182 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 25004 bytes -4824 bytes (-16.17%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 25417 bytes -4411 bytes (-14.79%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 26970 bytes -2858 bytes (-9.58%)
Brotli (Wikipedia) brotli brotli -q 11 27998 bytes -1830 bytes (-6.14%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 28614 bytes -1214 bytes (-4.07%)
LZMA2 (Wikipedia) xz xz -9 29172 bytes -656 bytes (-2.20%)
Zstandard (Wikipedia) zstd zstd -19 29453 bytes -375 bytes (-1.26%)

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.