Choose a version:
24% The original file has 380273 bytes (371.4k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 91828 bytes (89.7k, 24%).

After GZIP compression these minified files vary in size:
Boot
  36011 bytes (35.2k)
CDN
cdnhttps
  31525 bytes (30.8k)
CDN
cdnjs
  31475 bytes (30.7k)
CDN
gzip -6 (default)
  31393 bytes (30.7k)
local copy
gzip -9
  31345 bytes (30.6k)
local copy
7zip -mx=9 -tgzip
  29936 bytes (29.2k)
local copy
libdeflate -12
  29919 bytes (29.2k)
local copy
kzip -s0 -rn -b3
  29905 bytes (29.2k)
local copy
pigz -11 -n
  29875 bytes (29.2k)
local copy
Zopfli
  29800 bytes (29.1k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.6.3.min.js

You will automatically get the smallest Dojo 1.6.3 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

Save 1675 bytes by using my Dojo 1.6.3 Zopfli version instead of the best available CDN (5.62% smaller than cdnjs, 29800 vs. 31475 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 --mls512 --bsr15 --lazy --ohh

(found December 2, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 512  --mls512
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 http://download.dojotoolkit.org/release-1.6.3/dojo.js --location | md5sum
e80d79f3564d83f970bbf99a569475a8  -
curl --silent --compressed http://minime.stephan-brumme.com/files/dojo/dojo-1.6.3.min.zopfli.js.gz | md5sum
e80d79f3564d83f970bbf99a569475a8  -

SHA1:
curl --silent --compressed http://download.dojotoolkit.org/release-1.6.3/dojo.js --location | sha1sum
ce41b81caccfa6ee676fa72d23c44757f024d8ea  -
curl --silent --compressed http://minime.stephan-brumme.com/files/dojo/dojo-1.6.3.min.zopfli.js.gz | sha1sum
ce41b81caccfa6ee676fa72d23c44757f024d8ea  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 36011 bytes e80d79f3564d83f970bbf99a569475a8 March 19, 2015 @ 15:33
cdnjs 31475 bytes e80d79f3564d83f970bbf99a569475a8 February 8, 2015 @ 14:45

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
cdnhttps 31525 bytes f85bcaf829c5df4ea08b98a22f24c439 < /*
< Copyright (c) 2004-2012, 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 an optimized version of Dojo, built for deploymen [...]
< development. To get sources and documentation, please vis [...]
<
[...]
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:

1.13.0,
1.12.3, 1.12.2, 1.12.1,
1.11.5, 1.11.4, 1.11.3, 1.11.2, 1.11.1, 1.11.0,
1.10.9, 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
29800 bytes -3 bytes zopfli --i100000 --mls512 --bsr15 --lazy --ohh December 2, 2015 @ 11:42
29803 bytes -1 byte zopfli --i10000 --mls512 --bsr15 --lazy --ohh November 22, 2015 @ 22:21
29804 bytes -2 bytes zopfli --i10000 --mls8 --bsr30 --lazy --ohh September 24, 2015 @ 17:48
29806 bytes -2 bytes zopfli --i1000 --mls8 --bsr30 --lazy --ohh September 24, 2015 @ 17:39
29808 bytes -4 bytes zopfli --i1000 --mls512 --bsr15 --lazy --ohh September 20, 2015 @ 04:49
29812 bytes -5 bytes zopfli --i1000 --mls512 --bsr14 --lazy --ohh September 10, 2015 @ 22:47
29817 bytes zopfli --i100 --mls512 --bsr14 --lazy --ohh September 10, 2015 @ 15:07

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
29842 29862 29843 29864 29851 29856 29878 29869 29880 29874 29866 29874 29872 29872 29870
29846 29845 29844 29844 29857 29870 29861 29861 29870 29860 29862 29870 29871 29871 29872
29831 29817 29828 29867 29827 29823 29849 29861 29837 29869 29862 29866 29861 29871 29868
29849 29843 29838 29837 29836 29832 29861 29859 29826 29865 29879 29855 29872 29861 29871
29821 29823 29817 29839 29846 29818 29868 29866 29828 29867 29863 29862 29869 29872 29871
29820 29842 29838 29840 29838 29835 29854 29858 29864 29867 29860 29870 29858 29872 29869
29826 29833 29811 29835 29822 29845 29866 29861 29858 29865 29853 29858 29871 29868 29860
29840 29835 29830 29839 29841 29834 29858 29858 29871 29854 29859 29866 29861 29860 29864
29815 29819 29819 29838 29835 29830 29855 29851 29831 29854 29852 29862 29864 29869 29867
29834 29837 29815 29832 29828 29829 29852 29854 29823 29852 29867 29859 29858 29869 29868
29808 29803 29827 29828 29828 29830 29835 29853 29804 29854 29855 29870 29865 29872 29870
29837 29802 29842 29826 29831 29831 29853 29862 29800 29855 29851 29866 29882 29872 29869
29811 29809 29818 29828 29840 29830 29854 29861 29864 29869 29861 29869 29876 29868 29871
29813 29831 29841 29842 29842 29847 29860 29858 29831 29865 29868 29862 29859 29869 29868
29822 29818 29843 29832 29836 29824 29816 29863 29825 29865 29865 29861 29858 29869 29868
29846 29815 29814 29823 29835 29820 29867 29857 29819 29865 29861 29863 29859 29864 29873
29839 29842 29810 29838 29835 29819 29842 29859 29841 29867 29817 29855 29870 29859 29868
29819 29812 29811 29837 29831 29849 29867 29864 29864 29867 29865 29862 29869 29875 29864
29845 29818 29816 29840 29829 29850 29859 29864 29863 29854 29861 29865 29861 29864 29869
29818 29813 29808 29839 29829 29818 29812 29857 29824 29866 29852 29866 29861 29869 29868
29816 29828 29815 29836 29838 29827 29837 29864 29809 29854 29854 29856 29877 29869 29871
29841 29834 29802 29830 29835 29830 29866 29857 29801 29851 29863 29863 29858 29869 29868
29812 29816 29812 29838 29837 29833 29853 29864 29823 29855 29862 29866 29862 29872 29871

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 29813 bytes 100%
1,000 29806 bytes -7 bytes 100%
10,000 29803 bytes -3 bytes 100%
100,000 29800 bytes -3 bytes 1.74%
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
29918 bytes +118 bytes (+0.40%) +13 bytes
29914 bytes +114 bytes (+0.38%) +9 bytes
29955 bytes +155 bytes (+0.52%) +50 bytes
29905 bytes +105 bytes (+0.35%)
29947 bytes +147 bytes (+0.49%) +42 bytes
29940 bytes +140 bytes (+0.47%) +35 bytes
29950 bytes +150 bytes (+0.50%) +45 bytes
29933 bytes +133 bytes (+0.45%) +28 bytes
29973 bytes +173 bytes (+0.58%) +68 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 23528 bytes -6272 bytes (-21.05%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 26436 bytes -3364 bytes (-11.29%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 27441 bytes -2359 bytes (-7.92%)
Brotli (Wikipedia) brotli brotli -q 11 27533 bytes -2267 bytes (-7.61%)
LZMA2 (Wikipedia) xz xz -9 28464 bytes -1336 bytes (-4.48%)
ZSTD (Wikipedia) zstd zstd -19 29253 bytes -547 bytes (-1.84%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 29329 bytes -471 bytes (-1.58%)

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