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:
gzip -6 (default)
  31392 bytes (30.7k)
local copy
gzip -9
  31345 bytes (30.6k)
local copy
7zip -mx=9 -tgzip
  29939 bytes (29.2k)
local copy
libdeflate -12
  29918 bytes (29.2k)
local copy
kzip -s0 -rn -b3
  29909 bytes (29.2k)
local copy
pigz -11 -n
  29875 bytes (29.2k)
local copy
Zopfli
  29797 bytes (29.1k)
local copy
Zopfli (defluff)
  29796 bytes (29.1k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.6.5.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.6.5 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 --i1000000 --mb8 --mls512 --bsr15 --lazy --ohh

(found February 27, 2020)
Description Value Parameter
iterations 1000000  --i1000000
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

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 (29796 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://download.dojotoolkit.org/release-1.6.5/dojo.js --location | md5sum
02e0ab3f7bea057e03de8c9cae26808e  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.6.5.min.zopfli.js.gz | md5sum
02e0ab3f7bea057e03de8c9cae26808e  -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.6.5/dojo.js --location | sha1sum
23b121f2567bdf047846ca19337405ce41545366  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.6.5.min.zopfli.js.gz | sha1sum
23b121f2567bdf047846ca19337405ce41545366  -

Other Versions

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

1.16.3, 1.16.2, 1.16.1, 1.16.0,
1.15.4, 1.15.3, 1.15.2, 1.15.1, 1.15.0,
1.14.7, 1.14.6, 1.14.5, 1.14.4, 1.14.3, 1.14.2, 1.14.1, 1.14.0,
1.13.5, 1.13.4, 1.13.3, 1.13.2, 1.13.1, 1.13.0,
1.12.5, 1.12.4, 1.12.3, 1.12.2, 1.12.1,
1.11.8, 1.11.7, 1.11.6, 1.11.5, 1.11.4, 1.11.3, 1.11.2, 1.11.1, 1.11.0,
1.10.10, 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,
1.8.14, 1.8.13, 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,
1.7.12, 1.7.11, 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,
1.6.5, 1.6.4, 1.6.3, 1.6.2, 1.6.1, 1.6.0,
1.5.6, 1.5.5, 1.5.4, 1.5.3, 1.5.2, 1.5.1, 1.5.0,
1.4.8, 1.4.7, 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, 1.2.2

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
29797 bytes -2 bytes zopfli --i1000000 --mls512 --bsr15 --lazy --ohh February 27, 2020 @ 17:20
29799 bytes -2 bytes zopfli --i100000 --mls512 --bsr15 --lazy --ohh February 26, 2020 @ 19:30
29801 bytes -2 bytes zopfli --i100000 --mls8 --bsr30 --lazy --ohh January 28, 2020 @ 19:07
29803 bytes -2 bytes zopfli --i10000 --mls8 --bsr30 --lazy --ohh January 28, 2020 @ 18:28
29805 bytes -4 bytes zopfli --i1000 --mls8 --bsr30 --lazy --ohh January 28, 2020 @ 15:03
29809 bytes -2 bytes zopfli --i1000 --mls2 --bsr14 --lazy --ohh January 28, 2020 @ 14:06
29811 bytes zopfli --i100 --mls512 --bsr15 --lazy --ohh January 28, 2020 @ 13:20

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

Most recent activity on February 27, 2020 @ 17:52.

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, 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
29842 29862 29851 29859 29851 29860 29878 29868 29878 29872 29866 29882 29880 29877 29871
29845 29845 29844 29844 29857 29869 29861 29861 29867 29860 29864 29865 29871 29871 29861
29830 29817 29828 29867 29824 29824 29844 29860 29836 29869 29858 29862 29861 29871 29867
29850 29844 29839 29843 29831 29831 29858 29858 29824 29858 29813 29855 29859 29861 29867
29821 29820 29816 29833 29846 29817 29860 29867 29830 29866 29873 29862 29868 29868 29868
29820 29841 29838 29839 29838 29838 29854 29858 29866 29867 29858 29863 29873 29860 29868
29825 29832 29812 29835 29822 29844 29866 29859 29858 29857 29852 29857 29871 29868 29860
29840 29835 29831 29839 29835 29833 29858 29858 29868 29866 29851 29866 29861 29871 29863
29814 29819 29819 29837 29833 29830 29854 29850 29830 29854 29852 29861 29864 29871 29869
29834 29837 29815 29832 29828 29828 29852 29857 29823 29852 29865 29862 29858 29863 29870
29801 29805 29827 29826 29826 29830 29850 29853 29805 29853 29852 29869 29859 29871 29870
29837 29804 29842 29825 29827 29830 29851 29862 29797 29853 29852 29866 29880 29871 29869
29811 29808 29804 29827 29832 29828 29854 29863 29851 29860 29856 29868 29876 29871 29867
29813 29832 29841 29841 29839 29846 29856 29858 29832 29858 29855 29862 29858 29869 29868
29822 29818 29842 29831 29829 29823 29815 29859 29826 29858 29858 29861 29858 29869 29868
29835 29813 29810 29829 29836 29821 29864 29857 29821 29864 29858 29863 29858 29860 29869
29838 29842 29810 29845 29834 29819 29840 29859 29843 29866 29814 29857 29817 29859 29868
29822 29812 29812 29842 29831 29848 29860 29862 29864 29860 29851 29862 29858 29875 29860
29845 29819 29818 29840 29839 29851 29829 29864 29864 29860 29857 29862 29818 29864 29869
29819 29819 29808 29834 29829 29817 29811 29859 29823 29866 29852 29865 29857 29871 29860
29816 29827 29815 29831 29834 29826 29837 29863 29808 29853 29854 29856 29877 29869 29868
29833 29832 29801 29833 29834 29829 29865 29857 29803 29851 29862 29862 29858 29860 29864
29813 29815 29812 29837 29836 29833 29842 29859 29822 29854 29861 29866 29862 29874 29873

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 29811 bytes 100%
1,000 29805 bytes -6 bytes 100%
10,000 29802 bytes -3 bytes 100%
100,000 29799 bytes -3 bytes 0.87%
1,000,000 29797 bytes -2 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
29925 bytes +128 bytes (+0.43%) +16 bytes
29925 bytes +128 bytes (+0.43%) +16 bytes
29959 bytes +162 bytes (+0.54%) +50 bytes
29909 bytes +112 bytes (+0.38%)
29951 bytes +154 bytes (+0.52%) +42 bytes
29941 bytes +144 bytes (+0.48%) +32 bytes
29955 bytes +158 bytes (+0.53%) +46 bytes
29937 bytes +140 bytes (+0.47%) +28 bytes
29977 bytes +180 bytes (+0.60%) +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.
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 23528 bytes -6269 bytes (-21.04%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 26436 bytes -3361 bytes (-11.28%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 27441 bytes -2356 bytes (-7.91%)
Brotli (Wikipedia) brotli brotli -q 11 27518 bytes -2279 bytes (-7.65%)
LZMA2 (Wikipedia) xz xz -9 28460 bytes -1337 bytes (-4.49%)
Zstandard (Wikipedia) zstd zstd -19 29121 bytes -676 bytes (-2.27%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 29331 bytes -466 bytes (-1.56%)

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 2020.
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.