Choose a version:
24% The original file has 375162 bytes (366.4k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 89537 bytes (87.4k, 24%).

After GZIP compression these minified files vary in size:
Boot
  35093 bytes (34.3k)
CDN, direct link
cdnhttps
  30605 bytes (29.9k)
CDN, direct link
cdnjs
  30598 bytes (29.9k)
CDN, direct link
gzip -6 (default)
  30487 bytes (29.8k)
local copy
gzip -9
  30449 bytes (29.7k)
local copy
libdeflate -12
  29118 bytes (28.4k)
local copy
7zip -mx=9 -tgzip
  29077 bytes (28.4k)
local copy
kzip -s0 -rn -b1
  29060 bytes (28.4k)
local copy
pigz -11 -n
  29005 bytes (28.3k)
local copy
Zopfli
  28927 bytes (28.2k)
local copy
Zopfli (defluff)
  28926 bytes (28.2k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.4.6.min.js

You will automatically get the smallest Dojo 1.4.6 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 1671 bytes by using my Dojo 1.4.6 Zopfli version instead of the best available CDN (5.78% smaller than cdnjs, 28927 vs. 30598 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 --mls64 --bsr21 --lazy --ohh

(found December 1, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 64  --mls64
block splitting recursion 21  --bsr21
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 (28926 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://download.dojotoolkit.org/release-1.4.6/dojo.js --location | md5sum
236773fb6591a973bca9d7f9aec239cb  -
curl --silent --compressed http://minime.stephan-brumme.com/files/dojo/dojo-1.4.6.min.zopfli.js.gz | md5sum
236773fb6591a973bca9d7f9aec239cb  -

SHA1:
curl --silent --compressed http://download.dojotoolkit.org/release-1.4.6/dojo.js --location | sha1sum
4f44c0e93a7c808736260867a23ee16428af4200  -
curl --silent --compressed http://minime.stephan-brumme.com/files/dojo/dojo-1.4.6.min.zopfli.js.gz | sha1sum
4f44c0e93a7c808736260867a23ee16428af4200  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 35093 bytes 236773fb6591a973bca9d7f9aec239cb March 19, 2015 @ 15:31
cdnjs 30598 bytes 236773fb6591a973bca9d7f9aec239cb February 8, 2015 @ 14:45

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
cdnhttps 30605 bytes 5c491ed983c27190d90d6295bddffeaf < /*
< Copyright (c) 2004-2013, The Dojo Foundation All Rights R [...]
< Available via Academic Free License >= 2.1 OR the modifie [...]
< see: http://dojotoolkit.org/license for details
< */
<
< /*
< This is a compiled version of Dojo, built for deployment [...]
< development. To get an editable version, please visit:
<
[...]
December 24, 2015 @ 07:33

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

Other Versions

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

1.12.2, 1.12.1,
1.11.4, 1.11.3, 1.11.2, 1.11.1, 1.11.0,
1.10.8, 1.10.7, 1.10.6, 1.10.5, 1.10.4, 1.10.3, 1.10.2, 1.10.1, 1.10.0,
1.9.11, 1.9.10, 1.9.9, 1.9.8, 1.9.7, 1.9.6, 1.9.5, 1.9.4, 1.9.3, 1.9.2, 1.9.1, 1.9.0,
1.8.12, 1.8.11, 1.8.10, 1.8.9, 1.8.8, 1.8.7, 1.8.6, 1.8.5, 1.8.4, 1.8.3, 1.8.2, 1.8.1, 1.8.0,
1.7.10, 1.7.9, 1.7.8, 1.7.7, 1.7.6, 1.7.5, 1.7.4, 1.7.3, 1.7.2, 1.7.1, 1.7.0,
1.6.3, 1.6.2, 1.6.1, 1.6.0,
1.5.4, 1.5.3, 1.5.2, 1.5.1, 1.5.0,
1.4.6, 1.4.5, 1.4.4, 1.4.3, 1.4.2, 1.4.1, 1.4.0,
1.3.3, 1.3.2, 1.3.1, 1.3.0,
1.2.3

The project site contains an overview how well these versions were compressed.
Other interesting projects are AngularJS, BackboneJS, Bootstrap, D3, Ember, jQuery, Knockout, lodash, React, Socket.IO, ThreeJS, UnderscoreJS and Vue.

Changelog

Best Zopfli parameters so far:
Size Improvement Parameters Found
28927 bytes -3 bytes zopfli --i100000 --mls64 --bsr21 --lazy --ohh December 1, 2015 @ 16:50
28930 bytes -7 bytes zopfli --i10000 --mls64 --bsr21 --lazy --ohh September 23, 2015 @ 19:46
28937 bytes -3 bytes zopfli --i1000 --mls64 --bsr21 --lazy --ohh September 23, 2015 @ 18:22
28940 bytes zopfli --i100 --mls64 --bsr21 --lazy --ohh September 22, 2015 @ 11:56

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 @ 14:36.

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
28995 29008 29007 29001 28999 29006 29008 29016 29012 29020 29009 29011 29024 29017 29014
28980 29005 29006 28987 28985 28983 28969 28990 28991 28996 28966 29013 29013 29019 29008
28985 28988 28981 28979 28974 28996 28978 28982 28993 28995 28990 29014 28986 29015 29018
28976 28982 28982 28991 28979 28986 28972 28973 28992 28993 28989 29020 29020 29016 29015
28978 28978 28984 28981 28974 28985 28975 29011 28972 28980 28971 29013 29012 29016 29011
29002 28973 28981 28989 28975 28990 28973 28970 28993 28984 28983 29009 28998 29006 29008
28979 28977 28958 28986 28987 28965 28973 28973 28991 28989 28981 29010 28988 29011 29011
28977 28976 28974 28972 28974 28974 28974 28972 28976 28974 29009 29014 28991 29011 29008
28972 28991 28978 28975 28971 28955 28974 28976 28952 28988 28981 29009 29019 29015 29015
28975 28970 28979 28973 28981 28972 28971 28982 28978 28978 28992 28963 29020 29014 29008
28977 28980 28978 28966 28974 28972 28971 28992 28983 29013 28986 29009 29002 29016 29016
28973 28967 28980 28972 28975 28980 28977 28968 28977 28980 28982 29009 29020 29016 29015
28978 28971 28958 28986 28978 28969 28974 28972 28977 28986 28983 29009 28963 29016 29016
28973 28977 28983 28982 28988 28974 28975 28973 28985 28989 28974 29010 29012 29005 29007
28982 28979 28955 28987 28971 28982 28974 28963 28984 29002 28989 29014 29018 29017 29007
28985 28982 28981 28983 28976 28978 29010 28963 28979 28995 28995 29009 28992 29007 29012
28958 28953 28956 28960 28980 28973 28978 28978 28982 29013 28991 29008 28983 29005 29006
28970 28985 28978 28992 28966 28927 28975 28975 28981 28983 28992 29008 28986 29018 29015
28956 28964 28986 28983 28970 28969 28979 28980 28986 28987 28990 29020 28970 29017 29015
28983 28968 28975 28984 28983 28974 28968 28968 28976 28981 28989 29021 28985 29018 29007
28973 28970 28977 28976 28975 28968 28976 28972 28985 28978 28980 29011 29019 29016 29015
28960 28980 28968 28970 28974 28949 28974 28971 28977 28980 28973 29018 29014 29007 29008
28974 28978 28979 28974 28971 28966 28976 28968 28984 28978 28981 29010 29012 29016 29016

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 28940 bytes 100%
1,000 28937 bytes -3 bytes 100%
10,000 28930 bytes -7 bytes 100%
100,000 28927 bytes -3 bytes 0.29%
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
29071 bytes +144 bytes (+0.50%) +11 bytes
29060 bytes +133 bytes (+0.46%)
29105 bytes +178 bytes (+0.62%) +45 bytes
29075 bytes +148 bytes (+0.51%) +15 bytes
29094 bytes +167 bytes (+0.58%) +34 bytes
29089 bytes +162 bytes (+0.56%) +29 bytes
29079 bytes +152 bytes (+0.53%) +19 bytes
29085 bytes +158 bytes (+0.55%) +25 bytes
29131 bytes +204 bytes (+0.71%) +71 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 23025 bytes -5902 bytes (-20.40%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 25801 bytes -3126 bytes (-10.81%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 26700 bytes -2227 bytes (-7.70%)
Brotli (Wikipedia) brotli brotli -q 11 26853 bytes -2074 bytes (-7.17%)
LZMA2 (Wikipedia) xz xz -9 27756 bytes -1171 bytes (-4.05%)
ZSTD (Wikipedia) zstd zstd -19 28507 bytes -420 bytes (-1.45%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 28646 bytes -281 bytes (-0.97%)

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