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
  29912 bytes (29.2k)
local copy
pigz -11 -n
  29875 bytes (29.2k)
local copy
Zopfli
  29798 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-1.6.4.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.6.4 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 --i1000000 --mb8 --mls2 --bsr14 --lazy --ohh

(found February 27, 2020)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 2  --mls2
block splitting recursion 14  --bsr14
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 2 more bytes (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-1.6.4/dojo.js --location | md5sum
6270dfa08820b1dd5b4900f9872d9f0a  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.6.4.min.zopfli.js.gz | md5sum
6270dfa08820b1dd5b4900f9872d9f0a  -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.6.4/dojo.js --location | sha1sum
6cce8b49be4eb9d6a46108ae2e84e3b65fce3229  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.6.4.min.zopfli.js.gz | sha1sum
6cce8b49be4eb9d6a46108ae2e84e3b65fce3229  -

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
29798 bytes -2 bytes zopfli --i1000000 --mls2 --bsr14 --lazy --ohh February 27, 2020 @ 17:55
29800 bytes -1 byte zopfli --i100000 --mls2 --bsr14 --lazy --ohh February 27, 2020 @ 11:18
29801 bytes -2 bytes zopfli --i100000 --mls8 --bsr30 --lazy --ohh January 28, 2020 @ 18:24
29803 bytes -2 bytes zopfli --i10000 --mls8 --bsr30 --lazy --ohh January 28, 2020 @ 17:43
29805 bytes -2 bytes zopfli --i1000 --mls8 --bsr30 --lazy --ohh January 28, 2020 @ 16:36
29807 bytes -2 bytes zopfli --i1000 --mls512 --bsr15 --lazy --ohh January 28, 2020 @ 14:19
29809 bytes -2 bytes zopfli --i1000 --mls512 --bsr30 --lazy --ohh January 28, 2020 @ 13:53
29811 bytes zopfli --i100 --mls2 --bsr14 --lazy --ohh January 28, 2020 @ 13:36

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 @ 17:56.

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 29847 29859 29851 29861 29879 29868 29879 29871 29865 29868 29880 29878 29870
29845 29840 29844 29844 29857 29869 29871 29861 29867 29860 29863 29865 29870 29869 29862
29825 29822 29827 29867 29830 29824 29837 29860 29836 29869 29856 29863 29868 29871 29867
29848 29844 29839 29846 29835 29830 29859 29858 29852 29858 29856 29854 29878 29861 29871
29816 29825 29817 29838 29846 29813 29861 29866 29827 29866 29860 29861 29868 29868 29871
29819 29841 29838 29839 29838 29837 29863 29858 29859 29867 29859 29863 29873 29860 29868
29825 29836 29810 29834 29822 29839 29863 29860 29857 29858 29852 29859 29863 29868 29860
29839 29834 29830 29839 29834 29832 29858 29858 29868 29867 29858 29866 29861 29859 29867
29815 29823 29817 29838 29836 29830 29855 29860 29830 29853 29851 29863 29868 29865 29862
29834 29836 29814 29831 29827 29828 29851 29857 29820 29851 29851 29861 29856 29863 29870
29798 29819 29827 29827 29826 29829 29834 29852 29818 29853 29853 29863 29861 29871 29870
29836 29805 29843 29823 29829 29836 29852 29862 29803 29854 29852 29865 29882 29873 29870
29818 29809 29817 29825 29837 29831 29850 29863 29851 29860 29857 29862 29869 29873 29869
29812 29831 29841 29841 29838 29843 29863 29859 29832 29858 29856 29861 29858 29871 29868
29822 29819 29842 29831 29828 29818 29863 29859 29827 29858 29858 29863 29866 29869 29868
29835 29818 29811 29829 29834 29816 29864 29857 29814 29865 29858 29862 29858 29858 29868
29839 29844 29819 29839 29832 29817 29846 29859 29839 29866 29814 29857 29869 29858 29859
29820 29811 29811 29836 29830 29843 29851 29862 29864 29860 29853 29859 29866 29877 29859
29843 29819 29816 29840 29838 29850 29863 29864 29861 29860 29856 29865 29857 29862 29869
29818 29817 29808 29842 29829 29814 29816 29859 29820 29866 29851 29865 29858 29860 29868
29816 29828 29815 29839 29838 29826 29850 29863 29808 29853 29851 29856 29875 29872 29867
29833 29833 29801 29842 29835 29829 29850 29857 29803 29851 29861 29862 29858 29859 29868
29812 29819 29812 29837 29834 29834 29850 29859 29822 29854 29861 29866 29861 29862 29867

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 29800 bytes -2 bytes 0.58%
1,000,000 29798 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 +127 bytes (+0.43%) +13 bytes
29932 bytes +134 bytes (+0.45%) +20 bytes
29959 bytes +161 bytes (+0.54%) +47 bytes
29912 bytes +114 bytes (+0.38%)
29951 bytes +153 bytes (+0.51%) +39 bytes
29941 bytes +143 bytes (+0.48%) +29 bytes
29954 bytes +156 bytes (+0.52%) +42 bytes
29942 bytes +144 bytes (+0.48%) +30 bytes
29977 bytes +179 bytes (+0.60%) +65 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 23529 bytes -6269 bytes (-21.04%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 26436 bytes -3362 bytes (-11.28%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 27443 bytes -2355 bytes (-7.90%)
Brotli (Wikipedia) brotli brotli -q 11 27532 bytes -2266 bytes (-7.60%)
LZMA2 (Wikipedia) xz xz -9 28452 bytes -1346 bytes (-4.52%)
Zstandard (Wikipedia) zstd zstd -19 29119 bytes -679 bytes (-2.28%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 29344 bytes -454 bytes (-1.52%)

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.